FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: ACHiPo on December 18, 2016, 11:25:34 AM
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I'd assumed that using a set of roller rockers on an Edelbrock RPM would be the best and most reliable top end for a mild stroked 427 street motor using a BBM block. I've been seeing things that suggesting T&D doesn't recommend their roller rockers for the street (not sure whether that is current information). They recommend inspecting every 2000 miles for fatique cracks, which doesn't give me confidence that it's a good solution for my application?
Thoughts?
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Absolutely no worries about using T&D rockers on the street.
However, if you're looking for something more economical, we have access to "new" non-adjustable factory style rocker setups that work extremely well with milder hydraulic roller applications.
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I called them (T&D) when I was looking for a system for my truck.
Their words to me were something like, aluminum has a fatigue/failure lifetime.
So I'm sure they don't want folks running them everyday on the street, then wanting replacements if/when they fail. That would be a PITA.
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I like to use the non-adjustable OEM style with good shafts, studs, and end supports, if we are .600 lift or less. The end supports are not a requirement if you are "mild" enough. It requires the effort to set them up one time, then bolt them down and forget about it.
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I don't think T&D meant that to dissuade you from buying their rockers. They do have "street" rockers and "race" rockers and if aluminum caused that much fuss, then no other rocker manufacturer would offer aluminum bodied rockers. Pretty sure Comp's Ultra Gold and Ultra XD rockers are both aluminum and they offer a lifetime warranty on them...
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I called them (T&D) when I was looking for a system for my truck.
Their words to me were something like, aluminum has a fatigue/failure lifetime.
So I'm sure they don't want folks running them everyday on the street, then wanting replacements if/when they fail. That would be a PITA.
Turbo,
T&D's fatigue statement is what I read that made me skeptical. I'm ok with the initial cost if it makes for a reliable, fun car. If I need to rebuild the motor every 20k miles (even if that's only every 10 years so not every day on the street, but whenever I want), I'd like a better solution.
AC
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I like to use the non-adjustable OEM style with good shafts, studs, and end supports, if we are .600 lift or less. The end supports are not a requirement if you are "mild" enough. It requires the effort to set them up one time, then bolt them down and forget about it.
This might be a good way to go for me. The idea of using rollers makes a lot of sense compared to sliding surfaces, but there are an awful lot of motors with 100k or more miles with traditional rockers so it's got a good track record.
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I don't think T&D meant that to dissuade you from buying their rockers. They do have "street" rockers and "race" rockers and if aluminum caused that much fuss, then no other rocker manufacturer would offer aluminum bodied rockers. Pretty sure Comp's Ultra Gold and Ultra XD rockers are both aluminum and they offer a lifetime warranty on them...
Brent,
Thanks. I was wondering about their "Street" rockers and whether the comment I read applied to them. I suspect they meant that race motors may only have a few hundred hours on them before rebuild, as opposed to a street motor that sees (hopefully) a couple thousand before needing a rebuild. Everything fatigues, but steel is better than aluminum for a given design, which is not to say you can't use Al to make reliable parts. Guess I can contact them and ask.
AC
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I don't think T&D meant that to dissuade you from buying their rockers. They do have "street" rockers and "race" rockers and if aluminum caused that much fuss, then no other rocker manufacturer would offer aluminum bodied rockers. Pretty sure Comp's Ultra Gold and Ultra XD rockers are both aluminum and they offer a lifetime warranty on them...
I agree with you. But for me it was something to think about as I am often out in the middle of nowhere in my truck after many cycles in the city.
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Less things to fail=less chance of failure. If you had lash to deal with, the street T&D is probably the highest quality option right now. Same rocker quality as the paired shafts. The weak link being the traditional mounting vs. the HD paired shaft design. We use beehives and non-adjustables for hydraulic streeters to reduce the chance of a failure in the middle of nowhere, like Turbohunter described.
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After seeing you build a few of those Blair I would go that way if I had to do it again.
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I wouldn't hesitate to take off and drive to California with the T&D rockers, then turn around and drive back. An aluminum bodied rocker arm just isn't something that I would consider a higher failure rate part, unless we were talking about Procomp parts. If you wanted absolute simplicity, then it needs to be a flat tappet camshaft and a factory rocker.
With that being said, sometimes it comes down to budget and a less expensive part being able to handle the job. If you compare a $1000 set of T&D rockers to a $450 set of "new" non-adjustable rockers with end stands and studs, then you're saving a lot of money and still ending up with new parts that will handle a hydraulic roller camshaft with ease.
I'm on my 3rd build with new factory non-adjustables in the past few months and I must say that I prefer the simplicity. It would be a little more challenging for the DIY'er to measure for accurate pushrod length, but other than that, I see no drawbacks. I do find that the non-adjustables will let a hydraulic roller FE rpm a little higher with the same parts. I pair them up with a set of end stands from POP.
(http://i170.photobucket.com/albums/u267/shellvalleyowner/Mobile%20Uploads/IMG_3696_zpscqm85o4a.jpg)
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I'm on my 3rd build with new factory non-adjustables in the past few months and I must say that I prefer the simplicity.
"New factory non adjustables"
I didn't know there was such a thing?
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Yeah, there are a couple of companies now offering complete setups with new rockers, shafts, springs, etc. It's a great offering.
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New non-adjustable 1.72 or 1.76 ratio?
Richard
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This is one of the reason I used factory adjustables. Very simple durable setup.
With a street cam, the sliding surface isn't really all that much slidin.
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Yeah, there are a couple of companies now offering complete setups with new rockers, shafts, springs, etc. It's a great offering.
Sorry double post.
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Yeah, there are a couple of companies now offering complete setups with new rockers, shafts, springs, etc. It's a great offering.
Brent,
Can you post or PM the companies? My search is coming up empty.
AC
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They are usually available through engine parts warehouses. You can have your builder check for them. I buy mine through Motorstate.
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They are usually available through engine parts warehouses. You can have your builder check for them. I buy mine through Motorstate.
Thanks.
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Yeah, there are a couple of companies now offering complete setups with new rockers, shafts, springs, etc. It's a great offering.
Brent,
Can you post or PM the companies? My search is coming up empty.
AC
Here is the typical pricing spread:
www.ebay.com/itm/252641867218
www.ebay.com/itm/162197188175
Several other vendors on eBay. Search "Ford FE Rockers".
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Yeah, there are a couple of companies now offering complete setups with new rockers, shafts, springs, etc. It's a great offering.
Brent,
Can you post or PM the companies? My search is coming up empty.
AC
Here is the typical pricing spread:
www.ebay.com/itm/252641867218
www.ebay.com/itm/162197188175
Several other vendors on eBay. Search "Ford FE Rockers".
Quite a savings over T&Ds that's for sure!
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Where is the break point as in lift, spring pressure and such between a set up like that and rollers.
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I've ran them to 6500 with about .600" lift and 350 over the nose.
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Finally got around to contacting T&D. They recommend their steel rockers for street use--an extra $500.
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My opinion is .600 lift is about as far as you want to go due to side loading the guide as it paddles across the valve tip. A good radius on the tip, and dialing in the stand height is important. I won't use the OE rocker past 425 open pressure. Seat pressure is really no issue. I have been working on camshafts that have .525 lift, and valve jobs that maximize flow to .500 lift, to go along as a package for long-running street use with the non-adj rockers. High lifts on the street will wear things out, and planning around a lower lift program can still make big street power and maintain long term reliability.
We get the 427 Stock Eliminator cars in the 9's with .500 at the valve, and 390s in the 10.30s with .481/.490 lift. If one approaches it right, longevity on the street and low lift power can happen.
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Finally got around to contacting T&D. They recommend their steel rockers for street use--an extra $500.
So I seen the "an extra $500".
Well I must look that up.
I go to the T&D Machine Products site. Love that spiderweb. ;)
They are not giving up the price there, but they do give out tech.
It say's that the stock type are 1.60 and the Blue Thunder Thor, 1-piece Stand
1.650.
Is this true?
I have never measured a T&D rocker.
That's giving up a lot of cam if it is the case.
Most are measured at least 1.73 stock. ???
http://tdmach.com/bbf.html
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Finally got around to contacting T&D. They recommend their steel rockers for street use--an extra $500.
Unless you lack confidence in your engine builder, I would let them make the call on the rocker arms. They may or may not be in agreement with what you decide. With that being said, if you knew how many hundreds of FEs are out there running on the street with T&D aluminum street Rockers, you wouldn't be second-guessing the durability. They have good parts.
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Man I have been running aftermarket alum rockers for a LONG time, in fact, my current set in the 489 are over 10 years old. I have seen some Comp and Dove's break, but usually only with high spring pressure, and keep in mind those aren't bushed or bearings. My Ersons I think will last forever at flat tappet pressures, the weight is distributed across the bearing case and the pressures on each end just aren't that wild on a pure street engine
That being said, with hydraulic roller I am a huge proponent of the stock hyd rockers. However, I wouldn't hesitate to use any available name-brand rocker out there, and Ersons or T&D streets I wouldn't even think twice based on a failure rate of zero on every set I have seen or used.
I also second Brent's comment and add that if you don't trust the guy to pick a rocker, I am not sure I would trust him to build it....
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I think the T&D is the best aftermarket rocker there is for the FE, in most cases. It does cost more, and there are builds that just don't require them. I don't think the aluminum will give up. I ran a set of Scorpion aluminum rockers over 100,000 miles in a 514 cube 385 series engine in one of my trucks. I sent them back to be checked out, and they just sent a new set.....said they were lifetime warranty. Point being, the aluminum body did not fail over many miles with hydraulic roller spring pressure. I just like the simplicity of the non-adj rockers in engines that can use them. A little less money, and less moving parts. If you desire a roller tip, the T&D is the best, in my opinion. If you ran a solid roller in a cigarette boat, the stainless with paired shafts should be used.......
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Ford used aluminum rockers from Crane in Cobra Mustangs as an OE installation. They must have passed some significant long term durability testing to get the OK for that usage. On hydraulic spring pressure and rational lift builds I do not think aluminum will be a problem at all. I will agree on the T&D stuff being extremely high quality.
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Finally got around to contacting T&D. They recommend their steel rockers for street use--an extra $500.
Unless you lack confidence in your engine builder, I would let them make the call on the rocker arms. They may or may not be in agreement with what you decide. With that being said, if you knew how many hundreds of FEs are out there running on the street with T&D aluminum street Rockers, you wouldn't be second-guessing the durability. They have good parts.
This is more about feeding my OCD than trust in the builder--I'm chompin' at the bit to something, even if it's just picking out components that may never get put into my motor.
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Finally got around to contacting T&D. They recommend their steel rockers for street use--an extra $500.
So I seen the "an extra $500".
Well I must look that up.
I go to the T&D Machine Products site. Love that spiderweb. ;)
They are not giving up the price there, but they do give out tech.
It say's that the stock type are 1.60 and the Blue Thunder Thor, 1-piece Stand
1.650.
Is this true?
I have never measured a T&D rocker.
That's giving up a lot of cam if it is the case.
Most are measured at least 1.73 stock. ???
http://tdmach.com/bbf.html
They are 1.76:1, and I was wrong about pricing. The Edelbrock kit is $1176 and the steel rocker option adds another $608. I really like the idea of roller rockers, but for my cam and build, $1800 just seems crazy. Ultimately I'll let my engine builder decide--like I said I'm just enjoying learning and figuring this stuff out on my own.
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They are 1.76:1, and I was wrong about pricing.
How would you know, you don't own a set so how would you have measured them.
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They are 1.76:1 and the race rockers are available in different/custom ratios. Of course there's a tolerance to everything, but I don't know where all this 1.6-1.65 stuff came from.
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So, Brent, Barry, Jaym, etc......do you think if someone made these T&D style of NASCAR rocker for the FE, would they add significant RPM capability?
http://picclick.ca/NASCAR-TD-Roller-Rocker-Arms-220-Ratio-Chevy-311582161065.html
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They are 1.76:1 and the race rockers are available in different/custom ratios. Of course there's a tolerance to everything, but I don't know where all this 1.6-1.65 stuff came from.
From T&D web site. Must be true if it's says so on there web site.
http://tdmach.com/bbf.html
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Yes I do. They are super light without a big body and an adjuster hanging off the back.
My buddy had an older RCR engine go through his shop for a freshen up, used as a dirt track engine. It had an .800" solid roller in it. Of course it had small titanium valves, but the spring pressures were only 180 seat and 450-475 open, using $1000 PSI valve springs. Engine peaked at about 8000 rpm. I attribute the low spring pressures/high rpm to the fact that the valvetrain was super light as it used the rocker arms that you linked us to.
A rocker that's missing that adjuster is going to be much lighter.
I have had factory non-adjustables to 6500 with hydraulic rollers on the dyno. That's pretty difficult with a typical rocker arm with adjusters.
A T&D setup like the one linked would be really nice for an FE....strength and light-weight. However, it takes a lot of effort on the builder's part as pushrod length needs to be *carefully* measured, especially with a solid cam. No adjusters, so no way to adjust lash/preload.
I really like the factory non-adjustable rockers. Hard to talk some guys into it though, as a $350 rocker arm setup that looks like it was just pulled off of a '64 Galaxie doesn't look right on a $18k engine. :)
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They are 1.76:1 and the race rockers are available in different/custom ratios. Of course there's a tolerance to everything, but I don't know where all this 1.6-1.65 stuff came from.
From T&D web site. Must be true if it's says so on there web site.
http://tdmach.com/bbf.html
That's the rocker arm length...............not ratio.
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They are 1.76:1 and the race rockers are available in different/custom ratios. Of course there's a tolerance to everything, but I don't know where all this 1.6-1.65 stuff came from.
From T&D web site. Must be true if it's says so on there web site.
http://tdmach.com/bbf.html
That's the rocker arm length...............not ratio.
Huh ???
The rocker is 1.6" long? Which part?
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Center to center of rollers. That dimension helps determine what kind of spring you can put underneath it. The dimension from the fulcrum to the pushrod cup dictates the rocker ratio.
Their street rockers are 1.76:1.
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Buy the T @ D s , and be done with it ..very nice part and to me you making an investment on a part that you will have around for a long time .. Never cut corners on your build , Bud
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(http://i170.photobucket.com/albums/u267/shellvalleyowner/IMG_3871_zpsr6omxavk.jpg)
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They are 1.76:1, and I was wrong about pricing.
How would you know, you don't own a set so how would you have measured them.
Scotia,
I only know what the tech emailed me--they are 1.76:1 and I was wrong about the pricing.
AC
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(http://i170.photobucket.com/albums/u267/shellvalleyowner/IMG_3871_zpsr6omxavk.jpg)
Is the cheap vernier broken?
You are measuring a race rocker and it only reads 1.60.
The race rockers are 1.65.
Exactly how does this measurement tell you how much spring you can use?
"That dimension helps determine what kind of spring you can put underneath it. " your words
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That was a 1.8:1 351C race rocker. It was the first one I grabbed on the shelf. Those calipers were the first ones I grabbed as well. If you want me to measure it with my Brown & Sharpe mics and show you that it's a 1.6" length with greater precision, I can do that too. ;)
The length can change due to the geometry that's desired and when you start moving dimensions around, you gain/lose, retainer/spring clearance as well.
Merry Christmas. Go have fun with your family. Enjoy the grandkids.
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Howie... the 1.60 is the pivot length of the rocker like Brent said, not the ratio. The Blue Thunder for the FE is the same pivot length 1.60. These are "race rockers, and are available in many ratios, with 1.75 being standard, but 1.8 or 1.85 or even up to 2.0 available if desired. The Blue Thunder "THOR" head is a BBF or 385 series head, not FE, and the 1.65 or 1.75 as a custom is again... pivot length not ratio.
T&D make the rockers to order, so you can get any ratio and many offsets if desired, within reason. I have handled a few sets of T&D race rockers for both Blue Thunder and Edelbrocks, have them on my own engine, but never a "street" rocker assembly... so no idea on that stuff, yet. I'll admit the T&D catalog reads a little funny, but you didn't understand it correctly.
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I personally own a set "and a half" of T&D race rockers for Blue Thunder heads with 1.9 ratio...
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Thanks for all the inputs on this. It seems I've got my answers: 1) T&D indeed makes really good stuff, 2) the standard T&D aluminum street rockers are not recommended for a daily driver due to fatigue, 3) Any engine builder worth his salt can pick the right combination for my application,
Additionally: 4) for ~$1800 a set of T&D roller rockers with steel instead of aluminum rockers should work great for my application, or 5) for ~$300 a set of non-adustable steel OEM-style rockers that will also work great for my application.
Next question: for my mild application (hydraulic roller with <0.6" lift and running <6200 RPM), does it make sense for additional insurance to add ~$200 for some end stands and another ~$100 for spacers to replace the stock spacer springs?
Merry Christmas!
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I would say you've pretty much got it right save for one thing.
Your #2 statement is probably (according to the much more experienced guys/builders on the forum) a bit to concrete. You might amend that to say, if you're worried about aluminum fatigue then you might not want to buy these. However as the builders have stated, they are quite confident in the T&D quality. I put much more stock in the experience on the forum as to any interweb research that you (or I) may have done.
As for your question of end stands, everyone here seems to say yes and the smart side of my brain says it certainly can't hurt, only help.
To help solidify this thought for you I'm thinking of a freshen up for my truck engine to include a set of new non adjustables with stands.
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I would say the #2 statement is false altogether. I've got one customer who put 6000 miles on his T&D street rockers just this year alone. I also have numerous other customers who have extended time on T&D streets.
If you do go with a factory setup, I would use studs and end stands. Solid spacers are not required and the factory style springs work just fine. I have numerous setups out there just like that.
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I would say you've pretty much got it right save for one thing.
Your #2 statement is probably (according to the much more experienced guys/builders on the forum) a bit to concrete. You might amend that to say, if you're worried about aluminum fatigue then you might not want to buy these. However as the builders have stated, they are quite confident in the T&D quality. I put much more stock in the experience on the forum as to any interweb research that you (or I) may have done.
As for your question of end stands, everyone here seems to say yes and the smart side of my brain says it certainly can't hurt, only help.
To help solidify this thought for you I'm thinking of a freshen up for my truck engine to include a set of new non adjustables with stands.
Turbo,
Thanks. I based my second statement on an email from T&D that said fatigue can be an issue with aluminum rockers in street applications and his recommendation to use their steel rockers.
Regards,
AC
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I would say the #2 statement is false altogether. I've got one customer who put 6000 miles on his T&D street rockers just this year alone. I also have numerous other customers who have extended time on T&D streets.
If you do go with a factory setup, I would use studs and end stands. Solid spacers are not required and the factory style springs work just fine. I have numerous setups out there just like that.
Brent,
I'll defer to you and the other builders as you have a whole lot more experience than I do--I'm just relaying what the T&D tech wrote to me in an email.
Thanks for the recommendation on the studs and end stands, as well as the education on rockers in general.
Merry Christmas!
AC
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That was a 1.8:1 351C race rocker. It was the first one I grabbed on the shelf. Those calipers were the first ones I grabbed as well. If you want me to measure it with my Brown & Sharpe mics and show you that it's a 1.6" length with greater precision, I can do that too. ;)
The length can change due to the geometry that's desired and when you start moving dimensions around, you gain/lose, retainer/spring clearance as well.
Merry Christmas. Go have fun with your family. Enjoy the grandkids.
Interesting you do not have the answer.
Didn't think you had one.
Actual setup to measure a rocker sweep.
I run Ersons, they are marked 1.76 on the top. I don't get a full 1.76. And I know my way around a measuring stick.
(https://s5.postimg.org/y9xuzrg8n/DSCN1116.jpg) (https://postimg.org/image/3si087svn/)photo hosting sites (https://postimage.org/)
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Don't have one set up to measure right now.
But I can promise you from many past experiences that T&D is pretty flippin' close to correct.
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Howie, we are all proud of you because you put your engine together all by yourself.
However, insulting me or other forum members because you couldn't understand the terminology in the T&D catalog isn't really the best way to make friends.
I'm not sure what question I was supposed to have answered, but if you want to ask it again, I'll be more than happy to give you an answer.
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I am at a loss of what the issue is here.
1 - The measurement from center to center on each side of the pivot is the designed rocker ratio and can easily be measured
2 - Depending on how that rocker is designed to get there affects spring clearance (and pushrod clearance too). In other words, 1.76:1 (or any ratio) can be come about in different arm length combos, within the available space for a given rocker
3 - Functional rocker ratio CAN be slightly different when installed, and can even change throughout travel due to where the rollers, pushrods, valve tips engage, and even how far the adjuster is, or isn't, buried. However, the mechanical ratio of the rocker body is still the same
What would be more interesting than looking at total lift, would be to map out the lobe lift in 5 degree increments, then compare it to what the valve sees. I bet it'd be very different from a stock foot type rocker to a roller.
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Exactly Ross.
Sticking a dial indicator on a rocker arm to try and directly measure rocker arm ratio does absolutely nothing. What needs to happen is the dial indicator needs to be on the spring retainer and the lift at the valve needs to be compared to the dial indicator measurement directly on the lifter/lobe. You will lose all kinds of lift to incorrect stand height, pushrod adjuster depth (translates to sweep that doesn't open the valve), pushrod flex, etc. As a matter of fact, you can raise/lower the rocker stands by .015" increments and see differences in how much the lift at the valve changes.
It's a given that you're not going to see the exact lift that the cam card dictates. Engine builders spend a considerable amount of time trying to get the lift at the valve to what it needs to be....whether it's a max lift goal with minimal losses, or to make sure that the lift meets a lift rule.
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Not to mention rocker deflection, pushrod deflection, shaft and stand deflection, and even cam deflection on serious race stuff. On one system I ran I was able to verify .037 total lift loss compared to the system that replaced it.
Any angularity you put into the system will also change rate and angle data points - try adjusting a stock rocker a mile out using one pushrod and then as close as you can using a longer pushrod - - then report back.
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Brent you have it all wrong.
I'm telling you to pound sand.
You don't even talk a good game on the spiderweb let alone run something you own.
You could not cut 0.015" off the bottom of anything.
You don't have the gear.
Put that in your pipe and smoke it.
Now as for my picture.
The dial is on the spring and measuring the actual push on the valve. So There. ::)
I build cars laddie.
You're going to have step up your game to get there.
Edit: The question. "That dimension helps determine what kind of spring you can put underneath it. " Brent is referring to the 1.60 and 1.65
that I had shown. Please explain to all of those potential customers how you use that number to select the spring they need.
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Google my name. Then Google yours.
Have a nice day.
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That's enough please, gentlemen... ;)
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Jay - understand if you lock this one, but I dove into the catalog, both on the net and the PDF download version and may have found some things that could be confusing the discussion
I am trying hard to understand the 1.60/1.65 issue, and so far, the only thing I see on T&D's web page is rocker length listed at 1.60 for the FE and 1.65 for the 385s, not ratio. It even lists some as 3.00 for the Boss 9, because they surely don't have a 3.00 ratio rocker. and Boss 9's use a short and long rocker, which supports the length versus ratio
Now, digging deeper, if you go to the tab that discusses that rocker length, it shows two dimensions for length. "Fulcrum length" (then they show all the available ratios) and "Dimension A" (which honestly I am not sure why anyone would care enough about that dimension to post it) Dimension A is the fulcrum length plus 1/2 the shaft diameter
As far as fulcrum length, it does affect spring choice. Not in open/close pressure but in choosing a spring diameter. In fact, they even note it in the footnotes under Note 109: Will clear most common spring diameters. I haven't had to fight it on FEs, but I sure have had to either choose a smaller diameter spring or different style rocker on other engines that had interference issues with aluminum rockers in particular. It certainly needs to be watched.
The catalog does not advertise what the common FE T&D rocker ratio is, which surprises me (and I have never bought a set, so I can't say I ever measured a set or checked for clearance with a T&D rocker) but it does show that the 1600 series rocker (1.6 fulcrum) can be had in 1.50-2.00 ratio in .05 increments. The way T&D has to do it if they keep fulcrum length the same on the valve side is to move the cam side. Honestly that seems like a logical way to do it because they just drill the adjuster hole 1.0667 - .8000 from the fulcrum to change ratio and they don't have to mess with coming off the center of the valve by moving the valve side, or valve and spring diameter issues by moving the the pivot bore.
To the guys that use them, do the T&Ds work out to be 1.75:1 not 1.76?
I still agree with the statement that you have to check spring/retainer clearance to rocker body, especially with a big bodied alum rocker and especially with an FE which could have as much as 1.55 diameter valve spring.
Two more comments.
1 - I agree with the way Howie checked for lift using a dial indicator on the valve, it's the best you can do to see what the ratio ends up to be in final use at max lift or anywhere on the curve, as it accounts for all the mechanical loss (at least at zero RPM) and lash. In fact, I would even say that you could have some mechanical GAINS at some points on the curve where the ratio is above 1.76, especially if you have some push rod angularity, but it depends on setup
2 - I also agree with Brent that measuring rocker ratio using the fulcrum method to make sure you have what you think you have, especially with custom rockers. In fact, in the catalog on page 5 T&Ds show exactly that
In the end, if there is more to this argument, then I am missing it, but I think everyone is making valid points...except for the T&D catalog... which seems to focus on everything OTHER than ratio :)
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I've installed 4 sets of T&D race rockers. 3 sets have been 1.75 ratio (this is stamped right into the rocker, so hard to miss!), the fourth set had 1.8 ratio on the intake side. Ross is correct that the RATIOS are available in .05 increments from 1.50 to 2.0 RATIO... LOL. I'm not yelling but this whole ratio deal is crazy. It is not that hard to understand. The numbers that are in the T&D catalog list the fulcrum length or "pivot" length as Jesel calls it. That remains the same on all (the FE) rockers. It is basically the geometry of the stand and the cylinder head that determine this.
Also the T&D race rockers are available on center, .080 left and right offsets, as well as .170 and .250 offsets available. I have one set here that are on a set of Kuntz Pro ports that have a .500 offset on the intakes (ports moved over and custom one off sheetmetal intake, .937 double offset lifters etc.) so lots of options as they are basically all made to order and can be customized as long as the Engineers say it is possible and draw it out in CAD, then they can machine anything.
As far as spring clearance, I have used up to 1.650 diameter springs with these T&D rockers, some guys use 1.750 springs or have in the past on high RPM engines.. but maybe not on FE's, they just list it as that is designed into it, and will be a different dimension with different pivot lengths. The newer "high tech" springs being used now are better material and going back to 1.500 (ish) diameter dual springs, so bigger isn't always better.
I don't see what all the fuss is about, but maybe there is more too it between Howie and Brent. None of my business...
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Im pretty sure the T @ D s ok for street use , they would nt have street versions , race versions if they were nt . AND Barry , Brent , Blair would nt use them in a build , sell them in a build if there was issues with them. My car is not a daily driver , but i drive it and im not worried bout going in a long trip anywhere with them . Insurance for our classic or collector cars is what defines daily driver or not to me . My Grundy insurance allows 4000 miles a year average for my coverage . When i put this motor together , i never put a mile figure on it , more of an idea that at 3000-5000 miles a year i would build a stroker or something else before i ever wore this one out ..Bud
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Google my name. Then Google yours.
Have a nice day.
So I did as you said Brent....
this is Brent Lykins from Ohio:
(http://i.dailymail.co.uk/i/pix/2012/11/14/article-2232669-16048323000005DC-781_634x562.jpg)
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ROFL...
That cat has a little more hair than me. Nice 'fro....
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yep !! .. that's him ... lol
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NICE MUG SHOT BRENT ......
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(http://memeguy.com/photos/images/my-cousin-was-babysitting-my-daughter-this-is-what-she-sent-me-197827.jpg)
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Brent you have it all wrong.
I'm telling you to pound sand.
You don't even talk a good game on the spiderweb let alone run something you own.
You could not cut 0.015" off the bottom of anything.
You don't have the gear.
Put that in your pipe and smoke it.
Now as for my picture.
The dial is on the spring and measuring the actual push on the valve. So There. ::)
I build cars laddie.
You're going to have step up your game to get there.
Edit: The question. "That dimension helps determine what kind of spring you can put underneath it. " Brent is referring to the 1.60 and 1.65
that I had shown. Please explain to all of those potential customers how you use that number to select the spring they need.
Hurling insults at somebody who is trying to help? Nice, Howie. Shows a real lack of character.
Look at your pushrod angle compared to the rocker. Notice how it effectively puts the "push" point lower and nearer the shaft. The angle also changes the amount of lift that the rocker sees, or the effective lift of the cam lobe. Look at how far down or up your adjusters are. You know that this also changes the effective ratio. And if it's not clear how fulcrum length decreases or increases the length of the rocker, thereby changing the available space for a spring to fit, then maybe you should stick to building cars.