s14 sr20 Tomei solid lifter shimming question

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patchan
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Joined: Sun Oct 17, 2004 12:23 am

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Hello all,

I recently got my head freshly built with new BC springs, valves, stems, retainers, and keepers. Tomei solid lifters, and JWT s3 cams. Rockers have been machined based on Tomei's instructions and also set to take dual guides. I am using the Tomei test shims at the moment to do the shimming.

I actually did measurements before and after the rocker job too, to see if there was a difference. Before and after the rockers were modified, I was never able to fit my smallest feeler gauge I have ( .0015mm) in any of the exhaust side rockers. My readings on the intake side from front of engine to rear are .008, .010, .010, .007. I've searched around but did not find any threads with my situation.

Has anyone come across this situation where one side being that tight that you cannot get a small feeler gauge in? All my parts were bought new. Only thing used are actually the rockers, so I would've expected them to be a little loose. Any feedback or suggestions on this would be greatly appreciated.
Is it just the springs being new that cause them to be so tight on the exhaust side? Would there be any issues if I left it as is for the exhaust side and just adjust the intake side for now and reshim after getting the engine running to break in the parts and/or after my initial tune?

Thanks in advance!


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Hijacker
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Tomei solid lifters need to be paired with tomei poncams designed for the solid lifters. That could be your issue.

patchan
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Hijacker wrote:Tomei solid lifters need to be paired with tomei poncams designed for the solid lifters. That could be your issue.
Thanks for the comment.

I've actually seen builds up to a few years back with people running the Tomei solid lifters along with the JWT cams, both S3 and S4, but never heard of them reporting where one whole side was so tight.
Since it everything seems to rotate smoothly as far as I can see, and cams dont seem to be scoring or grinding, I will most likely get the motor back together and let it idle for awhile to break in the springs a little and then remeasure again.

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the converted
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You should be able to fit a feeler gauge in there when it's shimmed correctly. I don't know the specs, but I would guess if your intakes are in the 8-10 thousandth neighborhood your exhaust should be in the 10-12 thousandth neighborhood. Leaving the lifters that tight will melt your valves. Did you have any machine work done to the valve seats? It's possible that they might have been cut a little too much moving the valves further up in the head.

You can use solid lifters on a hydraulic lifter cam, but not the other way around. You won't get the gains that would come from a solid lifter cam though since you can do completly different things with the profiles on a solid lifter. I'm not sure about the Tomei's specifically, but I can't imagine that the base circle would be that different to keep you from shimming them properly.

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2_Liter_Turbo
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Ok, since I have had experience with issues pertaining to solid lifters I'll drop my .02 cents in (I run tomei solid lifters).

First thing is first. You MUST run solid lifter spec'd cams. Hydraulic lifter specific cams have too aggressive of a profile on the ramp up and down sides of the lobe. They will cause them to hit the valve seat way too fast and hard and it will damage the seats, valves themselves, cam lobes and eat through the shims (ask me how I know this... lol). Hydraulic lifters have give when they hit the seat, so you can run the profile more aggressively. You can run solid lifter cams on a hydraulic setup, but not the other way around.

Secondly, when you had the machine work done, did the machinist just drop the valves in after regrinding the seats? If so, this may be your issue. Valves typically need to have the tips ground to get the installed height within spec. It seems to me that your valves stem tips are sitting too high from the seal surface of the head. I honestly don't know what this height needs to be, otherwise I'd tell you so you could measure it.

There is some good news though. You can order smaller shims than the test shims. The test shims are sort of "middle of the range", so order up a full set of one size that's fairly thin for the side you can't get a feeler in. As for the other side, just adjust accordingly to the tomei equation.

Hope this helps! I've ran into tons of issues with solid lifters in the past and so I got pretty good with them before I got everything figured out, ha ha.

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the converted
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Interesting. I never thought about the effects on the seat itself. I know a few people that run mechanical lifters with hydro cams in domestic applications with no issues that they or I am aware of. Do you have any pictures of the damage? I'm just curious.

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2_Liter_Turbo
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the converted wrote:Interesting. I never thought about the effects on the seat itself. I know a few people that run mechanical lifters with hydro cams in domestic applications with no issues that they or I am aware of. Do you have any pictures of the damage? I'm just curious.
I don't have any pictures of the seats, because I was lucky enough not to damage those (at least visible), but I do have pictures of the valve stem tips and shims that were damaged if you want to see those. That's the reason why I ended up going with the Ferrea +1mm valves on my head, lol. Needed new valves anyways.

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the converted
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Definitely.

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2_Liter_Turbo
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Shims after just a couple hours of run time on hydraulic cams using solid lifters; yes they were gaped correctly,lol. (maybe less)...

Image

Can't seem to find the pic of the valve stem tip :facepalm:


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