FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: jayb on January 31, 2021, 04:57:33 PM
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So after the last round of testing with these heads, we were suspicious that the cam was not really optimized for this engine. Lykins went so far as to offer to get me a cam at no charge, that he thought would be better suited for the engine. Not one to look a gift horse in the mouth, I said sure LOL!
Then, after picking out some cam lobes that he thought would work, Brent went to order the cam and found out, to his chagrin and mine, that blanks for FE cams to achieve over 0.800" lift were not available! Brent called a couple places and so did I, but the only thing that could be done would be to order a custom blank at around $900. Neither one of us wanted to spend that, so Brent settled on a cam with just under 0.800" lift. Here are the specs for the original cam that I tested with (the Old Cam), and the New Cam:
Old Cam: Bullet solid roller, 319/334 Advertised, 285/292@.050", 0.880" gross valve lift on both lobes, 112 LSA, .030" lash on exhaust, .028" lash on intake. I degreed this cam at 110 ICL.
New Cam: Comp solid roller, 305/317 Advertised, 276/288@.050", 0.782 gross valve lift on both lobes, 111 LSA, .018" lash on exhaust, .016" lash on intake. I degreed this cam at 111 ICL.
I sure hope that sometime soon the blanks for more lift on an FE cam become available, but for now all we can do is work with what we've got. It took me a few days to break free long enough to get the cam installed, but this past Friday I was ready to go. I had also acquired some new PAC valve springs that were more suited for either of the cams. Instead of about 1050 pounds over the nose, these were 800 pounds over the nose of the new cam, while still maintaining about 300 pounds on the seat, to get that heavy intake valve closed properly.
Royce and a couple of my friends were here on Friday to help with the testing. We started off with the existing valve springs still in place. On startup the first thing we noticed was how much smoother the idle was with the new cam. Makes sense due to less duration and overlap, but the difference was really noticeable. After warm-up and lash, we ran the first pull from 3000 to 5000 RPM. The new cam was so much smaller than the old cam that I wasn't sure what would happen, but as it turned out, the engine did not care about the cam. Here is chart showing the results from the new cam and the original results from the old cam:
(http://fepower.net/Photos/Posts/OvN3-5.JPG)
These results were nearly identical, and given the more radical specs of the old cam, at this point I figured that the new cam would make less power up top. Wrong! Here is a chart comparing the two cams from 5000 to 7000 RPM:
(http://fepower.net/Photos/Posts/OvN5-7.JPG)
The new cam actually looks better at the top end than the old cam does. Go figure...
I'd been anxious to try a valve spring swap on the engine, because those big springs had served their purpose, by proving out the steel rocker arms. The swap was from PAC 1356 springs to PAC 1224 springs. I had made a tool to be able to swap the springs with the heads installed, and it took us a couple hours to get that done. After finishing, we warmed up the engine and ran the first pull from 3000-5000 RPM. The valvespring swap definitely picked up power, even at the lower engine speeds:
(http://fepower.net/Photos/Posts/OvNS3-5.JPG)
Finally, we worked our way up to the 5000-7000 RPM pull. Here the difference was even more pronounced:
(http://fepower.net/Photos/Posts/OvNS5-7.JPG)
The torque and HP improvements using the SE heads and the new cam and springs are shown below:
SE heads, 4V intake, old cam and springs, peaks: 842 HP, 719 lb-ft
SE heads, 4V intake, new cam and springs, peaks: 849 HP, 724 lb-ft
SE Heads, 4V intake, old cam and springs, average 3000-5000 RPM: 491.9 HP, 639.6 lb-ft
SE Heads, 4V intake, new cam and springs, average 3000-5000 RPM: 497.7 HP, 647.2 lb-ft
SE Heads, 4V intake, old cam and springs, average 5000-7000 RPM: 781.3 HP, 685.8 lb-ft
SE Heads, 4V intake, new cam and springs, average 5000-7000 RPM: 792.2 HP, 695.6 lb-ft
Peak HP and torque numbers can always be a little misleading, so it's nice to see such a solid improvement in the average numbers as well.
After finishing up with the 4V intake on Friday, Royce and I swapped on the 8V intake. But after a couple of tests and a jet change, we were down some on power. Paranoia is always present during a dyno session, so out of an abundance of caution we called it a day.
Yesterday I spent some time going over the engine, checking the valve lash, changing the oil, etc. Everything looked just fine, and not a trace of an issue when I cut apart the oil filter. So this morning I reviewed the data that we had collected on the 8V setup on Friday, and realized that after the jet change our A/F numbers were way lean. So this afternoon when I ran the engine again I re-jetted to get it right. Today everything looked good, and we got the same kind of improvements with the cam and spring change as we did with the 4V intake. Details below:
SE heads, 8V intake, old cam and springs, peaks: 854 HP, 725 lb-ft
SE heads, 8V intake, new cam and springs, peaks: 861 HP, 736 lb-ft
SE Heads, 8V intake, old cam and springs, average 3000-5000 RPM: 474.5 HP, 616.5 lb-ft
SE Heads, 8V intake, new cam and springs, average 3000-5000 RPM: 486.5 HP, 633.1 lb-ft
SE Heads, 8V intake, old cam and springs, average 5000-7000 RPM: 786.6 HP, 690.8 lb-ft
SE Heads, 8V intake, new cam and springs, average 5000-7000 RPM: 795.9 HP, 699.2 lb-ft
It is very interesting to me that the 8V intake is down on power in the 3000-5000 RPM range, compared to the 4V intake. I assume this is because of the two big Dominator carbs, not really working at the lower engine speeds. But they definitely take over at the top end. And 736 lb-ft of torque is 1.44 lb-ft per cubic inch. That is a really, really good number.
Next on the testing list is testing with the crossram intake manifold, then I'll swap back to the RE heads and repeat everything one more time. Based on the improvements I've seen with the SE heads, I'll bet the RE heads will peak right around 875 HP. Not 900, but pretty close, and not bad for heads that have not been ported.
I still have some work to do to to finalize, and potentially improve, the intake manifolds for this package. But at this point, I have beaten the living SH*T out of the heads, intakes, and rocker arms, and I am quite confident that they will hold up well in a street or race application. So, I'm pulling the trigger on production as of today. This week I hope to get current quotes for the castings from the aluminum and steel foundries, plus some of the other vendors I need to get parts from, and then I'll be able to finalize pricing on the package. If you are on my list for one of the cylinder head packages, I'll be in touch with you in a week or so. Thanks again to the forum for all the support on this project, I really appreciate it - Jay
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Well done Jay, and well done Brent with the cam. Gaining everywhere, even at low double digits, on the first try with an unknown combo is impressive
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That cam is a .455" lobe lift, so with a 1.76 rocker ratio, it should be right at .800" gross lift. It's interesting, on Comp's cam cards, they always compute the gross lift with the lowest rocker ratio that's available for that family. On an FE, the lowest ratio is a 1.73, so that's what they show on Jay's cam card.
This was about the largest lobe that I could have fit on a standard billet FE core without having issues with the heat treat. The durations were what I wanted, the LSA was what I wanted, but the cores were not available to do .500" lobe lift, so we had to settle. We are losing power to lift loss, but I'm pleased to see that engine pick up with a much smaller camshaft. The new cam was 9° smaller on intake duration than the old cam, .080" less lift, and about 10° less overlap. My guess was that it was just pushing power out the headers before.
The interesting part was gaining so much power through the mid range. At 5800 and 6300, the new cam looks to be about 25 hp and 25 lb-ft ahead.
Jay's onto a phenomenal cylinder head. Getting 850-860-870 hp out of a head that you can bolt on out of a box without port work is unreal.
Thanks to Jay for the opportunity to try out a cam. My nerves were a complete wreck on Friday, waiting for Jay to text with the results.
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Very nice guys! I'm happy that it's working out so well :D
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That new cam certainly looks better. More power with less duration is good. It doesn't look like the old cam was the reason for the engine peaking around 6500 rpm though.
An amazing project in any case. Hats off to you, Jay! Those heads rock!
paulie
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Great test and results.
I know I am in the minority but would like to see you do a test on a mild [compared to what you build] engine 428-445 etc with no change but your heads bolted on.
Oh well I can only hope but it would be real interesting to me.
Greg
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Watching these tests is very interesting as is your pursuit for more power by which many will eventually benefit .
I am definitely a newbie but I have a cam which might be of interest that you can have and try if you think it might be worth trying.
The specs are
Comp solid roller 307/320 advertised, 274/282 at .050, .799 gross valve lift at both lobes, 110LSA Slightly larger than cam # 2 I think?
Lobe lift is .462 on both intake and exhaust .
If it is of interest let me know
David
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I'm also wondering if these heads are feasible for milder builds or just all out race engines.
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Cool results and great work! Clearly we are dealing with a new performance level. As such, the optimum setups still need to be hashed out with experience. I think I am in the mild-build realm as some folks were asking but using a 4.375" stroke crank. Probably a 428 based block in a Cougar with less than optimum headers due to shock towers, power steering etc... My initial worry is wondering how suitable a standard 390/428 block would be. Adding cross bolts to the mains seems like a must. Not sure that alone will suffice. All that machine work expense may be better put towards an aftermarket block. I can see myself not getting too fixated on a HP number and just going for the best I can fit in the vehicle. The HP/TQ will be what it's going to be.
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That new cam certainly looks better. More power with less duration is good. It doesn't look like the old cam was the reason for the engine peaking around 6500 rpm though.
paulie
Paulie, I have to agree, although this new cam peaked a couple hundred RPM higher than the original cam that probably isn't the reason that the power is mostly flat after 6500 RPM. I think at this point that the reason is the airflow capacity of the heads. Horsepower means airflow, and with a cross sectional area that is only a few percent larger than a stock FE medium riser head, it may be that no more air can be crammed through there. I do think there is more power in the 8V intake though, and I may yet get closer to 900 HP. But even at this level, in a drag car with this engine you'd want to shift at 7500 anyway, because the engine would still be making good power at that point. And certainly with a smaller engine the HP peak would be higher in the RPM range.
I will keep working this issue, I'd like to wring everything I can out of this setup...
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Certainly these heads will work in a milder combination. The great thing about a really good cylinder head is that you don't need as much cam and compression to make a given amount of power. One thing about these heads though is that with the existing 2.300" intake valve size, you would need a 427 bore size at a minimum to make the valves fit.
However, I do have a different version of the SE head on the drawing board, with a slightly smaller intake port, and a smaller intake valve. Flow will not be as good on the intake side, but as designed it will fit a 4.08" bore, which is a 0.030 over 390 block. Just as a guess, those heads should flow at least 360 cfm on the intake. I will be building a 390 stroker dyno mule to test those heads out in the spring.
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Watching these tests is very interesting as is your pursuit for more power by which many will eventually benefit .
I am definitely a newbie but I have a cam which might be of interest that you can have and try if you think it might be worth trying.
The specs are
Comp solid roller 307/320 advertised, 274/282 at .050, .799 gross valve lift at both lobes, 110LSA Slightly larger than cam # 2 I think?
Lobe lift is .462 on both intake and exhaust .
If it is of interest let me know
David
Thanks for the offer, that cam does look interesting. Unfortunately I probably won't have time to start swapping more cams and doing more testing; the test schedule is already pretty full, and lots of related items need to get completed. If something frees up on that I'll get back to you - Jay
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congrats. bringing this along - cannot wait to see trends with many cams esp. what /how RE ex. does with new cam can fe head finely have a lot of ex. flow be showing up ? old fe guy would not know what to do esp. on top end .. possible less/no push rod flex with less spring psi. more bad fe's in the future or back to the 60s
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For the guys asking about the Milder builds . I would have to say yeah , they are going to benefit you but the flow on the heads and the power arent the only thing you are getting. You are getting access to the valley without taking the entire top end apart . You are getting infinite intake possibilities if Jay offers Intake starter flanges. You are getting gourmet type Rocker system .
So yeah , pretty much anyone would see a benefit from these . The argument could be made that you could buy other stuff and piece your own system together for some of this but this is all together in one shot and done. Tested and proven.... Who wouldnt benefit from that ?
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Jay,
What is the CI and CR on this engine?
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Jay,
What is the CI and CR on this engine?
Not Jay, but here’s a screenshot from an earlier post on the FE Power cylinder head testing which had the specs. As explained earlier in this post the cam & valve springs have been changed now. And here’s the link to this post:
http://fepower.net/simplemachinesforum/index.php?topic=9171.0;all
(https://i.postimg.cc/ZRG1vTnM/D8E4192C-3DA5-442C-9EF3-0EDCF25B49FE.jpg) (https://postimg.cc/dk9Wzc82)
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Jay, have you thought about adv the cam about 3*, it would give you a bit more dynamic compression.
Also, I would love to see the difference in the 850's vs the Dom's.
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Very cool Jay! Nice work.
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Jay, how difficult would it be to offer rocker arms in a 1.9-2.0 ratio? Not only would that let the valve lift go up, but a higher rocker ratio accelerates the valve quicker off the seat as well.
I think the new cam with an .880-.900" lift would be a big bump, but I also think that the port volume is small for a 510ci engine aiming for 900 hp and 7000-7500 rpm. I'd like to see those heads with about 15-20cc added to the port volume.
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That new cam certainly looks better. More power with less duration is good. It doesn't look like the old cam was the reason for the engine peaking around 6500 rpm though.
paulie
Paulie, I have to agree, although this new cam peaked a couple hundred RPM higher than the original cam that probably isn't the reason that the power is mostly flat after 6500 RPM. I think at this point that the reason is the airflow capacity of the heads. Horsepower means airflow, and with a cross sectional area that is only a few percent larger than a stock FE medium riser head, it may be that no more air can be crammed through there. I do think there is more power in the 8V intake though, and I may yet get closer to 900 HP. But even at this level, in a drag car with this engine you'd want to shift at 7500 anyway, because the engine would still be making good power at that point. And certainly with a smaller engine the HP peak would be higher in the RPM range.
I will keep working this issue, I'd like to wring everything I can out of this setup...
Jay, will you eventually test on a smaller displacement engine to prove your theory about port size being a bottle neck?
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Dang, that is impressive!!
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Jay, how difficult would it be to offer rocker arms in a 1.9-2.0 ratio? Not only would that let the valve lift go up, but a higher rocker ratio accelerates the valve quicker off the seat as well.
I think the new cam with an .880-.900" lift would be a big bump, but I also think that the port volume is small for a 510ci engine aiming for 900 hp and 7000-7500 rpm. I'd like to see those heads with about 15-20cc added to the port volume.
I just checked on this and it wouldn't be too difficult to get to 1.85:1, or even 1.9:1. Beyond that it's hard to say for sure, I'd need to have Bill run a strength and fatigue analysis, but there's enough meat in the rockers to go up to 2.0:1.
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Jay, how difficult would it be to offer rocker arms in a 1.9-2.0 ratio? Not only would that let the valve lift go up, but a higher rocker ratio accelerates the valve quicker off the seat as well.
I think the new cam with an .880-.900" lift would be a big bump, but I also think that the port volume is small for a 510ci engine aiming for 900 hp and 7000-7500 rpm. I'd like to see those heads with about 15-20cc added to the port volume.
I just checked on this and it wouldn't be too difficult to get to 1.85:1, or even 1.9:1. Beyond that it's hard to say for sure, I'd need to have Bill run a strength and fatigue analysis, but there's enough meat in the rockers to go up to 2.0:1.
That would be cheaper than a big cam core.
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Jay, will you eventually test on a smaller displacement engine to prove your theory about port size being a bottle neck?
I think rather than run on a smaller engine, I may get one set of the heads ported and re-test. As mentioned previously I will be building a 390 stroker to test the heads on, but due to the limitations of the block I don't think I can build this engine for the maximum potential power of the unported heads.
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Congrats Jay and thank you for putting forth the effort!
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Really impressive and also a surprise the raised exhaust ports are only a bit of extra power. Those are some really good standard exit ports!
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I am curious what gains might be had with just a simple sanding roll clean up of the ports would gain. As I recall, you gave a chopped section of the first prototype head to someone who did that, just cleaned them up enough to get rid of the casting surface. That helped somewhat didn’t it?
The heads as they are now have been blended just under the valve seat I am assuming?
I fully plan on hitting mine with a bit of sand paper to smooth the ports out, don’t think that can do anything but help.
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I'm sure you're right, most of the port is still a rough cast surface. I think the basic sand roll cleanup netted at least 10 cfm on the intake, not sure about that though. The valve job did include a cleanup under the seat, to make the inside seat diameter about 90% of the valve diameter, and then blend into the rest of the port. That's part of the normal valve job at my local shop.