FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: blykins on May 08, 2019, 03:15:33 PM
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I've had a customer messaging me back and forth about using Trick Flow heads on their FE.
I've used several sets of these so far and the issue is the same: the stand height is raised about .300" higher than a factory head. Their included valves are longer, which helps a little, but you still end up with a net .200-.250" height difference.
My customer decided to call Trick Flow to inquire and they told him that there is no issue as long as their valves are used.
Guys, this is absolutely not the case and if you follow their advice, you may end up with horrible geometry with the rocker arm riding the exhaust side of the valve tip. I know several of us have harped a lot on this, but my fear is that a lot of guys are gonna have premature valve guide wear if they don't bird-dog things on their own.
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Thanks.
They seem like really good heads in other respects.
paulie
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I just wonder how or why they are ignoring the feedback. It is one thing if a single customer says something but when builders state it, one would think Q.C. would investigate and confirm and possibly correct the issue.
Can the area be milled on the head or does it have to be the stands that get milled? Point being if the head can be milled, then they should correct it. It not, then they should confess the stands will need work done.
I wonder if any of the input is making it to their engineering vs. getting sidelined by lack of follow through. It just seems odd since an issue like this could hinder their sales, or are that may folks in the ignorance is bliss category?
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Why - with the wealth of knowledge from builders that have been there/done that would a manufacturer not include known design requirements in their product. "I know better than you other people that do the work" almost never works out.
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I sent them an email.
Blair told me that he has offered input on their intake manifold and it has fallen on deaf ears.
HJ, you could do either one....the stand pads are so high on the heads that it's blatantly obvious.
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Why are the TFS valves longer?
Is the port roof higher up?
Is the valve cover surface raised too?
Otherwise factory valve covers are going to bang into the valvetrain I'd think.
Sad that people at TFS would ignore advice from this forum's builders.
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The ports are not raised.
The stand height is. The stand pads are raised so high that the head bolt/stud nuts are completely under that plane.
I imagine the valves are longer to try and aid in the stand height difference, but it's simply not enough.
(https://live.staticflickr.com/1834/43496745634_6c23cdbe2c_z.jpg)
(https://live.staticflickr.com/1769/42016145295_e2e3bc8b3c_z.jpg)
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Geometry out of the box:
(https://live.staticflickr.com/1821/29530677218_9c85819234_z.jpg)
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Geometry with some T&D street rockers, after cutting .200" off the stands.
(https://live.staticflickr.com/65535/47757936472_db26854363_z.jpg)
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Good pics. That shows the issue very well. Why would not make the valves even longer or cut the heads correctly(preferred)?
I guess I just do not understand why they would not listen to some of the biggest names in FE building that have huge customer base(s).
That is why I asked if it "could be" done....I could partially understand it if the casting did not allow for it safely but if so , and seriously, the added cost in finishing correctly should be minimal.
They could likely save some of that cost back on less valve material ;D
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There is an article on a FE build in Car Craft using these. They appear clueless and sort of extroll the virtue of the raised pads. "May require longer pushrods"
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The ports are not raised.
The stand height and valve cover rails are.
The valve cover rails are raised as well? How does the valve cover actually seal correctly?
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The ports are not raised.
The stand height and valve cover rails are.
The valve cover rails are raised as well? How does the valve cover actually seal correctly?
I'll reneg on what I said until I find out for sure. I was thinking they were because of the potential rocker arm clearance issues that you would have. However, I don't have a set in here right now to check.
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I looks like somebody with no clue on rocker geometry designed those shaft mounting pads at that height. They look to be perfectly aligned at zero lift, which of course is not where they should be. Go figure...
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Are the threads deeper in head for rocker shaft stand bolts ?
Increased clamping force without pulling threads ?
If not and ports not raised , makes no sense .
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Not sure on that one, but all FE stand studs have the same base thread depth, so it would take something specially made if that were the case.
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We saw similar results when installing. The pics attached show rockers on MR stock heads and then as is on the TF heads. We ended up having to cut the rocker stands .200 to get the geometry correct. They run great compared to the stock heads and we saved about 20lbs a head with the swap.
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I looks like somebody with no clue on rocker geometry designed those shaft mounting pads at that height. They look to be perfectly aligned at zero lift, which of course is not where they should be. Go figure...
Looks like it was set up for mid lift with a 0.00" lift cam. :)
Otherwise looks like a very decent head offering.
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The TFS engineers are currently working on a solution.
And yes they do read these posts!
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I was talking about this with Ross last night and we were discussing an easy fix for them. Earlier in this thread, we talked about milling the stand pads down, but I'm not sure this is a viable solution as it would move the feed hole over, just as the hole in a rod journal moves over when you grind a crankshaft.
I suppose their drilling step could be adjusted to drill at the correct angle after milling the pads.
You could also lengthen the valves, but it would probably put the pushrods way up into the intake pushrod holes and cause some issues there.
Paulie, I agree with you.....I really like the cylinder heads. They flow well for a 170cc port (the ones I've cc'd here were a tad under that) and the chamber has a really nice shape. They seem to make excellent horsepower as well. I recommend their heads quite often, but it's always with a warning about the rocker stands.
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I'm missing something here. I thought it was something like common knowledge that you had to mill the stands .200" or so (not the pads on the heads. That would be foolish) and use custom pushrods to get the correct geometry. This was something that was highlighted as a caution for anyone when these heads first hit the market. Is that not what is being discussed?
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The helicoils are longer. The threads are deeper. I use a stud with more base thread to root it deeper. That is the one benefit to the pad being taller......more engagement. I just put the rocker stands in the mill and cut them down. It's not a big deal.....just not a bolt-on and go.
Biggest problem with milling the pads is that you will have to pull the helicoils out so you don't destroy an end mill, and then you have to put a shorter one back in there, defeating the purpose of having more thread engagement. If you cut the stands down, the thread hole is still on the same plane. There is effectively no difference in shaft placement in doing that, or milling stands.....the shaft would end up in the same spot.
The valve cover rail is not raised.
If you want to use their cylinder head, milling the stands is really not a huge deal. It is just a couple of hours of checking and milling. The checking always should happen on any head, and sometimes a change of some sort is required on any other head, depending on valve length, rocker arm, or cam lift. It's just part of building an "other than stock" engine. Just my opinion.
Brent mentioned that I had made suggestions to them about their manifold. I talked to them at the Cobra Jet Reunion. I had just finished a Trick Flow manifold before I went there. It had no drainback provision to get the oil out of the cylinder head oil drains. The man I spoke with said they would address that. I have done four of those intakes, and had to mill the drain into all four. Maybe they have fixed it......not sure how many were in circulation at the time we spoke. I don't think gasket thickness is enough space to drain the oil back. If you buy one, be sure to check for that. I mill the relief in there, but you can fix it with a template and a die grinder.....just FYI.
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I'm missing something here. I thought it was something like common knowledge that you had to mill the stands .200" or so (not the pads on the heads. That would be foolish) and use custom pushrods to get the correct geometry. This was something that was highlighted as a caution for anyone when these heads first hit the market. Is that not what is being discussed?
Changing pushrod length will not change the rocker arm geometry when the shaft is bolted in a fixed position. That only works when you can slide the rocker up and down a stud mount by changing pushrod length.
As many combos of lifters, heads, and rockers as there are available these days, you can never assume a pushrod length that puts your adjuster in a happy place. You should plan to measure and get correct pushrods for your specific engine. Just another one of my opinions.....
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Changing pushrod length will not change the rocker arm geometry when the shaft is bolted in a fixed position. That only works when you can slide the rocker up and down a stud mount by changing pushrod length.
As many combos of lifters, heads, and rockers as there are available these days, you can never assume a pushrod length that puts your adjuster in a happy place. You should plan to measure and get correct pushrods for your specific engine. Just another one of my opinions.....
Poorly written where I included the pushrods for geometry. I know pushrods have nothing to do with geometry on a shaft system. I meant you had to mill the stands to correct geometry and THEN use a custom length pushrod to get the ball stud in the proper adjustment position.
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As many combos of lifters, heads, and rockers as there are available these days, you can never assume a pushrod length that puts your adjuster in a happy place. You should plan to measure and get correct pushrods for your specific engine. Just another one of my opinions.....
Yes, pretty much a given on any motor. I just assume that procedure. It's easy - just measure, send a note to Brent with some numbers I get off on this colorful plastic card I have, then in a blink the perfect set of pushrods appear in my mail box. It's PFM for sure ;D
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Are the threads deeper in head for rocker shaft stand bolts ?
Increased clamping force without pulling threads ?
If not and ports not raised , makes no sense .
Beat me to it lol... Maybe that was their thought, but poor execution? Is there more thread engagement the way they come? Still has to fit right, one could (if there is room) go deeper into the head to get more engagement, but if it was that easy (that room thing) someone would have done it a long time ago
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The fact that Jegs & Summit sell these heads, and reading their description, leads a guy like me to believe that they are bolt on and go, to which they obviously aren't. TFS states they are a direct bolt on. Most back yard guys don't have a milling machine. I realize most out of the box aluminum heads may need some tweaking , but the need to lose .200 on stand height is crazy. No big deal to the regular builders, but a big deal to me after dropping big coin for a set of heads. Thank you Brent for the heads up on this.
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I'm missing something here. I thought it was something like common knowledge that you had to mill the stands .200" or so (not the pads on the heads. That would be foolish) and use custom pushrods to get the correct geometry. This was something that was highlighted as a caution for anyone when these heads first hit the market. Is that not what is being discussed?
That's not what Trick Flow is telling people. I spent the better part of 30 minutes explaining to a customer what needed to be done. He decided to call Trick Flow and confirm and they told him that they didn't need to be touched. I didn't really appreciate that, it made me look like an idiot.
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That's a significant failure on TF's part if they are not informing customers they can't just run their heads.
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I think Trickflow could do better.
JMO,
paulie
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The helicoils are longer. The threads are deeper. I use a stud with more base thread to root it deeper. That is the one benefit to the pad being taller......more engagement.
Thanks Blair
Deeper threads with studs that will use them should clamp better and eliminate some stand movement. I like it.
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looks like there is enough room to add a rocker stud for each valve
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Brent, approximately how much does it cost to make the TFS heads completely right? I normally don't ask about vendors about cost, but this seems like a tech issue.
thanks,
paulie
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I think Trickflow could do better.
JMO,
paulie
Had one of the intakes here.
Looks like it has potential with some tweaks.
It does seem like they never really installed these parts and ran them - we are the research and development department...
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Brent, approximately how much does it cost to make the TFS heads completely right? I normally don't ask about vendors about cost, but this seems like a tech issue.
thanks,
paulie
You mean to cut the stands?
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Maybe trick flow should include rocker stands at the correct height to match their heads? would the more engagement part of the higher stands on the TF heads result in a more stable valve train?
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If they supply stands, then you're locked into whatever rockers and shafts fit their stands. Needle bearing rockers, such as T&D, Harland Sharp, etc., use a different diameter shaft than a bushed or factory rocker. Some rocker bodies are different widths as well.
The stability will just depend on how much stud engagement you have. I have pulled stand studs out of the heads at 600 lbs open pressure on aluminum heads. I don't know how much more base thread you'd have to have to get around that. My SOP for big pressure solid rollers is to just use race rocker setups. I'm thinking about how much you'd have to whack off a TFS head to get the T&D race rocker mounting bar to sit where it needs to......wow......
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If they supply stands, then you're locked into whatever rockers and shafts fit their stands. Needle bearing rockers, such as T&D, Harland Sharp, etc., use a different diameter shaft than a bushed or factory rocker. Some rocker bodies are different widths as well.
The stability will just depend on how much stud engagement you have. I have pulled stand studs out of the heads at 600 lbs open pressure on aluminum heads. I don't know how much more base thread you'd have to have to get around that. My SOP for big pressure solid rollers is to just use race rocker setups. I'm thinking about how much you'd have to whack off a TFS head to get the T&D race rocker mounting bar to sit where it needs to......wow......
I thought this thread was about regular guys trying to use these heads out of the box. Race-prepping ANY head will require machining or other modifications.
What WOULD happen if someone tried to just bolt these on out of the box? Using their valves. Do the installation instructions say you have to get custom-length pushrods?
All this glossing over of longer valves...how much extra weight do those add; what effect does the added weight have on redine, imortant if you're wanting to use a hydraulic cam.
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This thread IS about guys trying to use them out of the box. All the discussion about machine work was to discuss what's necessary to make them correct and usable.
What would happen? You'd constantly be putting a side load on the valve. Nobody aims to put the pattern on the outside tip of the valve. We try to get the pattern near center to eliminate valve guide wear and eliminate lift loss. That's not really "race prep", it's just common sense.
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Brent, approximately how much does it cost to make the TFS heads completely right? I normally don't ask about vendors about cost, but this seems like a tech issue.
thanks,
paulie
You mean to cut the stands?
Yes.
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Brent, approximately how much does it cost to make the TFS heads completely right? I normally don't ask about vendors about cost, but this seems like a tech issue.
thanks,
paulie
You mean to cut the stands?
Yes.
$125-150. There's quite a bit of setup time in it.
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The problem I have is that TFS markets these as, "...a direct bolt-on for all 1961-76 engines."
While technically they do bolt right on, I think the average buyer reading that statement (beside an assembled head labeled "Street Port") would expect ready-to-run valvetrain be available over some counter somewhere.
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Brent, approximately how much does it cost to make the TFS heads completely right? I normally don't ask about vendors about cost, but this seems like a tech issue.
thanks,
paulie
Thank you.
You mean to cut the stands?
Yes.
$125-150. There's quite a bit of setup time in it.
Thank you.
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And the fact that the chambers are at least 2cc smaller than most other heads out there. I usually see them at a hair under 70cc.
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There is an article on a FE build in Car Craft using these. They appear clueless and sort of extroll the virtue of the raised pads. "May require longer pushrods"
We're not clueless, the stock stand height worked just fine for us. That engine made 700 hp and everything looked great. Those heads are a super nice design as were the other parts we used on that engine. The engine took a little more "fine tuning" than a typical Chevy or Mopar engine, but you kind of expect it with a FE engine. Especially when using a bunch of brand new parts. We had one of the first sets of TF heads as well as set #1 of the Comp rocker arms so stuff did have to be tweaked a little bit but we didn't have to machine the stands. Pushrod clearance was tight in several spots and the intake did end up on the milling machine a couple of times.
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this topic is confusing,all the different answers to the problem,or is there a problem.leaves me scratching my head,but i will have to stick with this forums engine builders because of their years of experience.so what does a body do with a new set of tf heads,bolt them on or have your shaft pads machined? they might have made 700 hp out of the box,but how long will this engine last,or should i say will it have future rocker-valve problems?
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Andyf it’s really interesting that you guys had a different outcome with the higher riser pads.
It would be neat to see a civilized/respectful discussion between all you great builders here.
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Between Blair and me, I think we have at least 3 TFS builds, with 3 different brands of rockers. All 3 required cutting the rocker stands down.
The other user that posted here also had to cut. That’s 4...
I would consider it a “must”.
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I thought it would be informative to post some mechanical drawings of what good rocker geometry looks like. The obvious difference is that with correct rocker geometry the travel across the top of the valve is reduced, and that brings benefits in terms of wear on the valve guide and reduction in friction in the valvetrain, especially if you are not running a roller tip rocker arm. From the pictures I've seen the Trick Flow heads look like they come out of the box with rocker arm geometry similar to what is shown in the first picture below. Will they run like this? Sure. Will they make power? Of course. Is it the ideal setup? Not by a long shot. This is why the rocker pads are being cut down by some of the folks here. Longer valves would also solve the problem. Since Trick Flow is offering the heads and the valves, it seems odd that they set it up this way. Seems like a design or manufacturing mistake to me. I hope they can get it corrected.
(http://fepower.net/Photos/Posts/Rocker Arm Geometry Incorrect.JPG)
(http://fepower.net/Photos/Posts/Rocker Arm Geometry Correct.JPG)
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The fact that longer valves are needed seems to be blithely dismissed. Don't longer valves weigh more, and doesn't that extra weight impact performance, particularly at higher rpm's, particularly with hydraulic cams, which may be the cam of choice for those purchasing 'out-of-the-box' bolt-on heads?
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Maybe I'm missing something, but if the raised pads come with more beef and thread engagement, wouldn't that be an advantage, since that is a weak point on most aluminum heads? And cutting the stands, instead of the head, would fine tune the geometry without loosing the extra strength. Not sure why one would want to give up the extra strength by cutting the pads instead of just cutting the stands?
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I'll venture that since the heads have already been distributed to a number of sellers already (and more sit in TFS's own warehouse) it would be quite difficult to retrieve them all, re-machine them and redistribute them. It's too late to easily and cheaply fix all those heads now. Perhaps TFS will change the pad height on future castings as part of overall machining.
Btw, they also could easily slap a sticker on every box indicating a need to a.) closely check stem sweep, perhaps using a drawing like Jay did above b.) recommend either longer valves or pad machining.
Bet though they won't do this as its an admission they aren't direct replacements without actual machine shop (no shaded tree, backyard stuff here!) pad reduction intervention.
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Maybe I'm missing something, but if the raised pads come with more beef and thread engagement, wouldn't that be an advantage, since that is a weak point on most aluminum heads? And cutting the stands, instead of the head, would fine tune the geometry without loosing the extra strength. Not sure why one would want to give up the extra strength by cutting the pads instead of just cutting the stands?
One reason would be clearance between the rocker body and the head, or the end stand. For example, if you tried to cut one of the Precision Oil Pumps end stands down, you'd probably turn it into two pieces and loose the benefit of the support out at each end of the rocker. If you were running solid spacers between the rockers, maybe the spacer would hit the head with the reduced stand height. The other issue would be fixturing in a machine. How would you easily fixture all the stands so you took the same amount off each one? It certainly could be done, especially if you used a rocker shaft for alignment, but I'll bet it would be more expensive than just cutting the rocker pad.
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I suspect they would address this about 5 seconds after someone starts marketing, "Rocker stands to make TFS heads a direct replacement."
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I know that is a generalized drawing there Jay, but in the case of the Trick Flow, the tip is actually pitched too far towards the exhaust side. Depending on the arch of the rocker arm (if any), a longer valve will not necessarily do the same thing as a change in shaft placement. If it was a "box" geometry that started with all 90° angles, up with one, or down with the other would accomplish the same things. If the set-up exists with "other than" 90° angles to start with the remedies get kinda blurry. Just for the sake of example....sometimes dropping the stand .200 might affect it more or less than a .200 longer valve, or vice versa. They do have a longer valve, but it isn't "longer enough", and it would create other issues like installed height problems to keep making the valve longer. The best fix for their deal is to lower the shaft, by whatever method suits a person's fancy. I agree that it will work, it has minimal effect on power, and yes, it will wear the guides out quicker over time than proper placement. It also can be hell on a valve tip and rocker if not a roller, as Jay suggested.
Seemed to me that milling the rocker stands and changing the studs is the best answer. The stands can be easily clamped in a Kurt vise and trimmed, and the studs can be bought with longer base thread. After the fix, the deeper root is actually better........it just needs to be done.
One of the problems when raising the port roof when using OE style mounting is than we start to run out of threads above the port. This doesn't happen quite as soon if the pad is taller and there are more threads left......just food for thought.
I think we shouldn't be too greedy about wanting an absolute bolt-on-no hassle situation when working with aftermarket heads. A bolt-on OE garden variety FE head will flow about 230 on my bench on a good day. That TFS that needs the stands milled will flow 308 here. If all it takes is milling the darn stands a little, big deal.....just my opinion.....for 80 cfm, seems like a pretty good deal.
Valvetrain geometry can get to be an infinite discussion, because there are so many conditions that can require so many different remedies. Sometimes, with really big camshafts with super high spring pressure, it is good to screw it up intentionally, in terms of the normal theory, to ease the burden past half lift, when ramps are stout, and spring pressure is high. Other times, with less than .500 lift, the tip will barely change position through the whole range. THAT is obviously what most of the street folks are looking for.
Maybe Trick Flow should just put a note in the box that when building a high performance engine, one should verify proper valvetrain geometry. I'm going to check it on all heads and all valvetrains. Over time, I see some things over and over with certain combos of parts. If you don't do it every day, you should check your individual situation out for yourself, or work with someone who can check it for you.
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I know that is a generalized drawing there Jay, but in the case of the Trick Flow, the tip is actually pitched too far towards the exhaust side. Depending on the arch of the rocker arm (if any), a longer valve will not necessarily do the same thing as a change in shaft placement. If it was a "box" geometry that started with all 90° angles, up with one, or down with the other would accomplish the same things. If the set-up exists with "other than" 90° angles to start with the remedies get kinda blurry. Just for the sake of example....sometimes dropping the stand .200 might affect it more or less than a .200 longer valve, or vice versa. They do have a longer valve, but it isn't "longer enough", and it would create other issues like installed height problems to keep making the valve longer. The best fix for their deal is to lower the shaft, by whatever method suits a person's fancy. I agree that it will work, it has minimal effect on power, and yes, it will wear the guides out quicker over time than proper placement. It also can be hell on a valve tip and rocker if not a roller, as Jay suggested.
Blair, thanks for the clarification on that, I don't have a set of those heads so I wasn't aware of the alignment issue.
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The obvious difference is that with correct rocker geometry the travel across the top of the valve is reduced, and that brings benefits in terms of wear on the valve guide and reduction in friction in the valvetrain....
Not to mention the amount of lift that you lose to unwanted movement. Anytime you see a wider witness mark, especially with a roller tip, you are losing some amount of valve lift because the rocker arm is too busy making a lateral movement instead of pushing the valve down. You already lose some to pushrod deflection, there's no need to compound it.
Most rocker stands that I've messed with so far will take the .200" cut off the bottoms without issue, including T&D streets, and POP center/end stands.
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I know that is a generalized drawing there Jay, but in the case of the Trick Flow, the tip is actually pitched too far towards the exhaust side. Depending on the arch of the rocker arm (if any), a longer valve will not necessarily do the same thing as a change in shaft placement. If it was a "box" geometry that started with all 90° angles, up with one, or down with the other would accomplish the same things. If the set-up exists with "other than" 90° angles to start with the remedies get kinda blurry. Just for the sake of example....sometimes dropping the stand .200 might affect it more or less than a .200 longer valve, or vice versa. They do have a longer valve, but it isn't "longer enough", and it would create other issues like installed height problems to keep making the valve longer. The best fix for their deal is to lower the shaft, by whatever method suits a person's fancy. I agree that it will work, it has minimal effect on power, and yes, it will wear the guides out quicker over time than proper placement. It also can be hell on a valve tip and rocker if not a roller, as Jay suggested.
Seemed to me that milling the rocker stands and changing the studs is the best answer. The stands can be easily clamped in a Kurt vise and trimmed, and the studs can be bought with longer base thread. After the fix, the deeper root is actually better........it just needs to be done.
One of the problems when raising the port roof when using OE style mounting is than we start to run out of threads above the port. This doesn't happen quite as soon if the pad is taller and there are more threads left......just food for thought.
I think we shouldn't be too greedy about wanting an absolute bolt-on-no hassle situation when working with aftermarket heads. A bolt-on OE garden variety FE head will flow about 230 on my bench on a good day. That TFS that needs the stands milled will flow 308 here. If all it takes is milling the darn stands a little, big deal.....just my opinion.....for 80 cfm, seems like a pretty good deal.
Valvetrain geometry can get to be an infinite discussion, because there are so many conditions that can require so many different remedies. Sometimes, with really big camshafts with super high spring pressure, it is good to screw it up intentionally, in terms of the normal theory, to ease the burden past half lift, when ramps are stout, and spring pressure is high. Other times, with less than .500 lift, the tip will barely change position through the whole range. THAT is obviously what most of the street folks are looking for.
Maybe Trick Flow should just put a note in the box that when building a high performance engine, one should verify proper valvetrain geometry. I'm going to check it on all heads and all valvetrains. Over time, I see some things over and over with certain combos of parts. If you don't do it every day, you should check your individual situation out for yourself, or work with someone who can check it for you.
Thank you- I was thinking with my Bridgeport mind, and had the same idea about putting the stands in an accurate mill vice, and keep the same setup for the next batch. The average wrap-around end stand thickness thing, a valid point, could be overcome with a little country thinking. In my mind, the extra beef and thread engagement is worth coming at it from a different direction
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I know that is a generalized drawing there Jay, but in the case of the Trick Flow, the tip is actually pitched too far towards the exhaust side. Depending on the arch of the rocker arm (if any), a longer valve will not necessarily do the same thing as a change in shaft placement. If it was a "box" geometry that started with all 90° angles, up with one, or down with the other would accomplish the same things. If the set-up exists with "other than" 90° angles to start with the remedies get kinda blurry. Just for the sake of example....sometimes dropping the stand .200 might affect it more or less than a .200 longer valve, or vice versa. They do have a longer valve, but it isn't "longer enough", and it would create other issues like installed height problems to keep making the valve longer. The best fix for their deal is to lower the shaft, by whatever method suits a person's fancy. I agree that it will work, it has minimal effect on power, and yes, it will wear the guides out quicker over time than proper placement. It also can be hell on a valve tip and rocker if not a roller, as Jay suggested.
Blair, thanks for the clarification on that, I don't have a set of those heads so I wasn't aware of the alignment issue.
TFS Engineer did say the valve angles have been changed from stock.
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We're not clueless, the stock stand height worked just fine for us. That engine made 700 hp and everything looked great. Those heads are a super nice design as were the other parts we used on that engine. The engine took a little more "fine tuning" than a typical Chevy or Mopar engine, but you kind of expect it with a FE engine. Especially when using a bunch of brand new parts. We had one of the first sets of TF heads as well as set #1 of the Comp rocker arms so stuff did have to be tweaked a little bit but we didn't have to machine the stands. Pushrod clearance was tight in several spots and the intake did end up on the milling machine a couple of times.
From the picture you posted, you can see that the rocker tip is off to the exhaust side at zero lift, just as Blair noted. And like Jay said, yes, it'll run and make power, but that is far from desirable in a geometry pattern. Defending the fact that it 'worked' only confuses people and will lead others to have problems down the road. So, it seems you guys were clueless. Sorry, don't mean to be rude about it, but the facts need to be set straight for people.
Given some of the benefits noted, it seems like they are a good set of heads, with the proper set-up and required work. A shorter stand means a shorter stud, and a shorter stud won't deflect as much, so that's a good thing. The sad part is that there are a lot of people who don't go internet-cruising to find out any and all issues. There are still a lot of backyard mechanics out there, and they will have problems. Pretty crappy business practice, IMO, for TFS to pass these off as "bolt-on". But that's what you get with businesses today. Luckily, we have the benefit of builders here who make us aware of these issues before we find out on our own...in most cases.
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(https://i.postimg.cc/4y81YWfh/683-A7-BEB-C3-C8-44-A8-B036-DCA90623-B4-AE.jpg)
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Would using highriser stands help/hurt/still need modifying?
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Can't imagine taking .200" off of the new Comp steel stands is quite as fun as with the other aluminum stands.
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I thought it would be informative to post some mechanical drawings of what good rocker geometry looks like. The obvious difference is that with correct rocker geometry the travel across the top of the valve is reduced, and that brings benefits in terms of wear on the valve guide and reduction in friction in the valvetrain, especially if you are not running a roller tip rocker arm. From the pictures I've seen the Trick Flow heads look like they come out of the box with rocker arm geometry similar to what is shown in the first picture below. Will they run like this? Sure. Will they make power? Of course. Is it the ideal setup? Not by a long shot. This is why the rocker pads are being cut down by some of the folks here. Longer valves would also solve the problem. Since Trick Flow is offering the heads and the valves, it seems odd that they set it up this way. Seems like a design or manufacturing mistake to me. I hope they can get it corrected.
(http://fepower.net/Photos/Posts/Rocker Arm Geometry Incorrect.JPG)
(http://fepower.net/Photos/Posts/Rocker Arm Geometry Correct.JPG)
Only problem is that your drawing isn't accurate. Do you have a set of TF heads on your bench? Do you have the Comp rocker arms on them? If not you might not have the drawing correct. We didn't see any of the problems that people are talking about. I'm guessing that nobody on here has Comp rockers on the TF heads? If not then why does everyone all worked up? If you haven't built it and tested it then what makes you an expert?
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Wow. At this point, we have five pages of discussion, some good info, several opinions, looks like a few feelings hurt.......all over an issue that can be cured for about $160 which would include some studs. If Trick Flow reads this, why don't you just add $80 to the cost of the heads, and furnish some studs with full thread engagement, and make the studs .100 shorter than an Edelbrock stud is from the top of the base thread to the other end. Then, they would root deeper, and the stud would work whether you cut the stands or not. Then we are down to an $80 milling job. It really ain't a big deal......
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Well, just looking at that picture of andyf's rocker arm, it is dangerously close to popping off the pushrod and at a terrible angle. Tells me all I need to know about not being correct. Just because something works does not mean it is correctly done. Joe-JDC
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I will get a head and a set of Comp rockers in here this week, mock it up, and report back.
My guess is that it will either be way off to the exhaust side of the valve, or it will be close to center but be way off towards the intake side of the valve on another cylinder head.
It stands to logic that if the Comp rockers fit the TFS heads perfectly, then they will need to be shimmed way up to work on another head.
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Can't imagine taking .200" off of the new Comp steel stands is quite as fun as with the other aluminum stands.
You do not need to worry about that.
Just got in a set of the new Comp rockers to try out.
The supplier for the steel stands had some sort of issue and the new ones are aluminum now.
Also wondering who and why they decided to have a snap ring groove machined in the end of the shafts.
Serves no purpose and makes a great spot for the shims to get caught up in.
Need to check ratio on this set - on dyno the engine I am running with them seems to be down a bit on power but its RPMing like crazy for a hydraulic roller deal - like 6700......
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Looking at that top picture it does look like the roller is on the exhaust side of the tip. And even at full lift it looks like it is still more on the exhaust side. Besides premature guide wear does it actually cost horsepower, and because of the angle of the rocker could that cause a problem were the push rod meets the rocker. What I mean by that is the adjuster at full lift is going to have a lot of stress on it. Or am I wrong thinking this way.
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Joe's last comment was aimed there. If the rocker shaft is too high, it will pitch the rocker on a funky angle at full lift. In addition to things happening on the long side of the rocker, the stand height also affects the pushrod angle at max lift. Lowering the stand will put less angle on the pushrod-to-adjuster making it less likely to spit out a pushrod.
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I guess I am going to have pull my valve covers and recheck mine. I thought they looked ok but after all this discussion I think I better look again...a little closer. I am running the older Dove wide body rockers on mine.
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How much shorter is the rocker pad to a high riser? Would it be easier to just shim a high riser stand?
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Would using highriser stands help/hurt/still need modifying?
How much shorter is the rocker pad to a high riser? Would it be easier to just shim a high riser stand?
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I wondered the same, but remembered this comment from an earlier discussion...
I think I would just get good billet aluminum stands and machine them. It would take a lot of shim under a High Riser stand, and they aren't cheap. The "base" of the standard OE stand isn't thick enough to mill .250 and still retain a good platform. We just put the shaft through the billet stands, and turn them upside down in the Kurt vise, and mill them all exactly the same.
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I wondered the same, but remembered this comment from an earlier discussion...
I think I would just get good billet aluminum stands and machine them. It would take a lot of shim under a High Riser stand, and they aren't cheap. The "base" of the standard OE stand isn't thick enough to mill .250 and still retain a good platform. We just put the shaft through the billet stands, and turn them upside down in the Kurt vise, and mill them all exactly the same.
thank you.. I missed that post
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I ordered a complete, assembled head from Trick Flow and rockers from Comp.
Got the cylinder head in, popped a couple of springs off, put checking springs on, then bolted the rockers on.
I'll pop up these photos and you all can discuss. I have my own thoughts, but I'd like to hear everyone else's first.
Initial position pictures reflect zero lift. The pattern shown reflects a simulated full lift of around the .800-.850" lift range, with about .125" retainer/seal clearance.
(https://live.staticflickr.com/65535/47813629092_ceb7e5e23c_z.jpg)
(https://live.staticflickr.com/65535/47865857941_dd9ccaa9be_z.jpg)
(https://live.staticflickr.com/65535/47813629372_f31d4ca74d_z.jpg)
(https://live.staticflickr.com/65535/40899235553_3448595e44_z.jpg)
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Not much to discuss really. It's pretty obvious the geometry is way off and the roller tip is right to the edge of the valve stem at lift, according to the wear pattern. Exactly what was pointed out earlier.
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I've had FE's since 1966. That is the worst rocker witness mark I have ever seen.
But then again,
I'm just a old Georgia redneck.
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Looks pretty bad to me. No doubt a person could make several dyno pulls for a magazine article without a catastrophic issue.
JMO,
paulie
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Let me throw this in....
The pattern is to the intake side with these rockers. The issues I’ve seen before with T&D rockers and factory rockers show the pattern to the extreme exhaust side.
Think about why it would want to start at the center and roll toward the intake side. See if you see what I’m thinking.
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What is the angle of the adjuster ball and the pushrod? Looks to be exaggerated, which would indicate that the stands are too high, or the pad too high, or the stands need to be cut down to bring into specifications. I stand by my earlier statement, just because something works does not mean it is right. Joe-JDC
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Yep, I still feel that it would be much better to shorten the stands han cut down the pads, and keep the extra strength of the extra beef and thread engagement. Just gotta think outside the box- like this
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Joe, I wasn't really paying attention to the adjuster end.
In an ideal situation, the rocker will start out near the center of the valve, roll outward a little and then back to where it was at full lift. You're aiming for a minimal contact patch.
In this situation, the rocker starts out near the center of the valve, but all further movement is directed to the intake side of the valve stem.
IMO, the stand pads are just too high. My gut tells me if I were to whack .200" off of these Comps, it would start to push things back to where they need to be.
I did a very rough measurement with calipers and the the Comp Cams rocker tip length is right around 1.500". Stand height is 1.400".
Here's a video:
https://www.youtube.com/watch?v=yhvZkI-k8us
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This geometri should give less lift if i am thinking right
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Nice demo, clearly needs the stands cut as many of us have said.
As you and I discussed before, it'd be nice if they could fix the issue AND keep the thread engagement, but if they won't, lopping .200 off really is an easy fix for a good flowing head
BTW, both sets of your rockers really came together nicely on the two 461s, with very different cam profiles, can't speak highly enough of them
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There are variables from different manufactures I would think, for example: In jays drawing he has the roller tip center, the push rod center and the shaft center on one plain. If you were to lower the shaft say .300 thousandths down from the imaginary line between the roller and the push rod you now have a greater distance from shaft to roller/push rod. You have not changed the ratio but would need to shorten the stands to keep correct geometry. Mixing rockers and stands? Do all rocker arm manufactures use one standard offset of the shaft to the imaginary line between roller and push rod? One stand height? How well are measurements held? Brent would be the man to know as he has hours developing a rocker that works. I'm sure the builders here have cut different amounts off stands. I look at it as you always degree a cam, always check rocker geometry and push rod lengths. There is no bolt on and go heads from big box stores, not even for chebby guys. Love the idea of extra material for strength and stability in the valvetrain. Shorter the stand, less deflection. Imo
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[quote author=fastf67 I look at it as you always degree a cam, always check rocker geometry and push rod lengths. There is no bolt on and go heads from big box stores, not even for chebby guys. Love the idea of extra material for strength and stability in the valvetrain. Shorter the stand, less deflection. Imo
[/quote]
This..
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At first I wondered if the rocker design may be playing into it, but those measurements you gave of the 1.5 tip length and 1.4 stand height seem to be about right, at least on a quick check of a stock rocker and stand I just looked at.
What are your thoughts as to why this one is erring on the side of the intake and not the exhaust, which seemed to be what the others experienced? Either way, it's still a horrible pattern...but good enough for a magazine build, I guess.
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Food nfor thought . Why not use a longer Valve ?
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Maybe 1/2 see's?
Cut the stands .100 and the pads .100?
Lotsa work but...................
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Food nfor thought . Why not use a longer Valve ?
\
As discussed earlier, the TFS head already uses a longer valve. I'm no expert, but it seems that making it even longer will cause other issues, like having super tall valve springs or having to shim them up to the point of not being feasible, or too much stem sticking up out of the guide, causing flex and wear issues.
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IMO, the stand pads are just too high. My gut tells me if I were to whack .200" off of these Comps, it would start to push things back to where they need to be.
As one of the biggest problems with running big cams and springs has been the 4-bolt attachment points that were never designed for that load, especially in aluminum, the taller and presumably much stronger pads would seem to be a big improvement, if you can make up the height difference elsewhere (shorter stands). You seem to be fixated on one (conventional) solution, cutting the pads, which would unnecessarily take away the strength advantage, when the height can fixed without giving up the extra strength. I would imagine one or more of the established sources that supply aluminum rocker stands could come up with a kit, with some input from the major players, with the proper height to work with the TF heads, including the end stands. Gotta get outside of the box and look from a different angle. Personally, I would work pretty hard at finding another way than cutting the pads down and giving up the strength
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Does the TFS box include (long) valves? If so, when you cut (whatever), do you just throw those long valves out and have to buy new ones?
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IMO, the stand pads are just too high. My gut tells me if I were to whack .200" off of these Comps, it would start to push things back to where they need to be.
As one of the biggest problems with running big cams and springs has been the 4-bolt attachment points that were never designed for that load, especially in aluminum, the taller and presumably much stronger pads would seem to be a big improvement, if you can make up the height difference elsewhere (shorter stands). You seem to be fixated on one (conventional) solution, cutting the pads, which would unnecessarily take away the strength advantage, when the height can fixed without giving up the extra strength. I would imagine one or more of the established sources that supply aluminum rocker stands could come up with a kit, with some input from the major players, with the proper height to work with the TF heads, including the end stands. Gotta get outside of the box and look from a different angle. Personally, I would work pretty hard at finding another way than cutting the pads down and giving up the strength
I've never advocated cutting the head pads. I always cut the bottoms of the rocker stands. What you quoted was me saying I would cut .200" off the bottoms of the rocker arm stands, which is what I've traditionally done so far. Cutting the pads on the heads would cause more problems, like moving the oil feed hole around, etc.
I also would never advocate a solid roller with a 4-bolt mounting setup in aluminum heads. Recipe for disaster.
The TFS valves are +.100" over stock length. I use those valves. If I didn't use those valves, the rocker stands would have to be cut down even more. Using an even longer valve could pose more issues in other spots, such as pushrod clearance, etc.
This post was not really to come up with different solutions to the problem, it was just a warning to those thinking that they can buy the heads, bolt them on out of the box, and use whatever rocker arm setup they wanted.
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What's the most you could cut off of the stands? Why wouldn't you cut them down to the bare minimum?
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I pulled the rockers off mine tonight for a double check. I only have maybe 50 miles on the heads. The contact pattern looks pretty good to me but I hope the experts will chime in. I didn't put anything the valves to check the contact for these pics, this just the bare valve. I am using Dove HD roller tip rockers.
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It looks like there is a difference in rocker arm pivot center lines between dove hd and comp
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Happen to took any pic at zero lift
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This is a TF head using Harland sharp rockers with needle bearings. The cam is a comp 308R with a .674 valve opening. The harland sharp is what TF recommends in their instructions that come with the heads.
(https://i704.photobucket.com/albums/ww45/mason427/ROCKER%202a.jpeg) (http://s704.photobucket.com/user/mason427/media/ROCKER%202a.jpeg.html)
(https://i704.photobucket.com/albums/ww45/mason427/ROCKER%201a_1.jpeg) (http://s704.photobucket.com/user/mason427/media/ROCKER%201a_1.jpeg.html)
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Mike, how's about a pic or two of the actual sweep on the valves stems?
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I usually jack those Sharps up about .200 on other heads. They look pretty good on there, LOL. Those Comps must have a shorter tip length than the Sharps.
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Howdy guys,
I asked about wear pattern a few weeks back and got the answers I needed,
but this has been extremely informative. Looked at the new Blue Thunder heads
I have to see if they had room to machine and it appears they do. Do the Edelbrock
heads have room to machine or do the stands still need to be machined on them also
or is this a case by case thing?
Thanks
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Is 0.200" of stud engagement critical, or even significant? Like as said, for high pressure solid roller cams you probable want more studs anyway, right?
paulie
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Interesting shot of the Harland Sharps. I went from Dove HD to Harland Sharps on Edelbrock
Heads. With a .760 lift I raised the sharps .125” in comparison to the Doves. Maybe Trick Flow designed their pad height around the Harland Sharp rockers......
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Here are some better pics of mine. This is with about .640 lift. The first pic is closed, second open and third pattern.
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Harland sharp rockers are recommended on the instruction sheet
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Am I correct in asumming from this discussion that different rocker arm manufacturers, even if they all use the same ratio of say 1.6 to 1, use different lengths as measured from the shaft centerline to pushrod ball center and valve contact point and not the OEM measurements ?
If that's true, no wonder geometry is all over the place.
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Balance of CC article - Page 1
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Balance of CC article - Page 2
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Balance of CC article - Page 3
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Thx Chris. Still, a little hard to read even expanded.
Do I take it they didn't alter the head's pads or cut the stands at all?
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It says the raised position “solved” some problems.
Solved?
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Thx Chris. till, a little hard to read even expanded.
Do I take it they didn't alter the head's pads or cut the stands at all?
Andy F. who wrote that article replied on page 3 & 5 of this thread that no machining of the pads or stands was done on the engine in the article.
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Thx Chris. till, a little hard to read even expanded.
Do I take it they didn't alter the head's pads or cut the stands at all?
Andy F. who wrote that article replied on page 3 & 5 of this thread that no machining of the pads or stands was done on the engine in the article.
Wow, that's amazing as how does only one rocker system work w/o machining.
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They don't look like they have the correct geometry from the pictures. My Dove's sit dead center and have about a .045 witness mark on the valve stem. Those look as if they are riding the furthest point out on the stem.
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Wow, nice thread (long).
My biggest pet peeve with the article was that the basics weren't given in either the July or August issues, like compression ratio (10.8, given online but not in the magazine we pay for) and cam specs for the Comp XR292R (not even listed for FE on Comp's website). Then again, dyno articles in the good old days didn't give cam specs either, and stuff like .050 duration or even .100 duration didn't exist.
https://www.hotrod.com/articles/new-product-overview-ford-fe-heads-trick-flow/#dsc_1831-jpg
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=1028&sb=2
As the Gonkulator compares all the FE heads these come out right there with the leaders of the pack which is highly commendable.
And, I get the idea of having longer valves for more lift & spring, and longer pads for more threads.
But those things also make it a Race Head, as the 5-6 pages in this thread show.
Why not offer a "Real Street Bolt On No Kidding" version of these heads, shorter valves, factory pad heights, so that stuff like the good old factory rocker setup will bolt on?
Seems it would vastly open up the potential market for these otherwise great heads.
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Thx Chris. till, a little hard to read even expanded.
Do I take it they didn't alter the head's pads or cut the stands at all?
Andy F. who wrote that article replied on page 3 & 5 of this thread that no machining of the pads or stands was done on the engine in the article.
The 2nd paragraph says "the intake manifold needed to be machined for pushrod clearance and so did the bottom of the rocker arms". Depends on how you read it I guess. No other details on the machining provided.
Also had a bit of a "moment" about the statement on the 3rd page that "...a few guys who couldn't wrap their heads about an FE engine making 700 hp on pump gas." Must be comfy under that rock.
Posted the pages because I didn't really have time to type all that info. TL-DT (too long - didn't type) ;)
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Thx Chris. till, a little hard to read even expanded.
Do I take it they didn't alter the head's pads or cut the stands at all?
Andy F. who wrote that article replied on page 3 & 5 of this thread that no machining of the pads or stands was done on the engine in the article.
The 2nd paragraph says "the intake manifold needed to be machined for pushrod clearance and so did the bottom of the rocker arms". Depends on how you read it I guess. No other details on the machining provided.
Also had a bit of a "moment" about the statement on the 3rd page that "...a few guys who couldn't wrap their heads about an FE engine making 700 hp on pump gas." Must be comfy under that rock.
Posted the pages because I didn't really have time to type all that info. TL-DT (too long - didn't type) ;)
Ah, got it as they did machine the rocker (stands). Thx.
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Apologies for resurecting this old topic, but I wondered if anyone might have discovered a final resolution to the TFS heads/rocker issue? I heard BLykins mention in one of his videos that Precision Oil Pumps offers already machined/made to fit rocker stands, however I was unable to find this on their website (I'm admittedly a newbie with all this). If Precision does indeed offer these, would someone please direct me to where they can be purchased? Thanks in advance!
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I've done more builds with the TFS heads than I can remember at this point.
What it boils down to is which rocker arm system you use. The Harland Sharp complete adjustable rocker system seems to bolt on without any issue. Most other rockers I've used will require some stand work.
These are fairly new with Precision Oil Pumps. Just call them and have him send you a set.
I've also arranged with POP to offer 1/4" longer stand studs for TFS heads. They have a 1/4" longer base thread, for more thread engagement for extra spring loads.
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I installed a set of TFS heads on the 428CJ in my 59 over the winter, I am running ISKY iron adjustable rocker arms (no roller tip, but they do have a curved, hardened pad on the valve end). On my iron CJ heads, I had been running the Oregon Cams stands and support system, but milling the Oregon Cams lower plates would make them very thin where they are machined to clear the head bolts, (which is not needed with the TFS heads, due to the taller rocker pads on the heads). So I called POP, and he said that he did offer rocker stands that were machined lower, but only .100". I spent a fair bit of time trying different rocker stand heights, different length pushrods, and measuring lift at the valve and valve stem pattern, and for my application (mild solid flat tappet Oregon Cam, dumb bell lifters, the Isky rockers, etc), I wanted stands .230" shorter than standard, and 9.450" long "ball and cup" pushrods. I ended up buying the regular POP stands, and had Brent machine them down . 230". That does make the end support fairly thin at the head bolt relief, (which isn`t really needed with the TFS heads), but with the smallish cam and mild valve spring pressures, I don`t expect on issues in that area. I put 2500 miles on the car with the TFS heads this year, and currently have the engine apart for an unrelated problem, and the supports all lok fine. One thing that I noticed while doing all that mockup and measuring, was how much valve lift can be lost with bad rocker geometry. All my previous FEs had used factory iron heads, mostly CJ heads, and standard type 4 bolt rockers, (factory FE adjustables, Ersons, Iskys, plus HD Doves with the end supports attached to the head bolts), so I never really gave the geometry very much attention, but this was quite an eye opener. Pretty easy to "lose" .030-.040" of valve lift with bad geometry.