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Hemi valve lash

Paul_G

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Indy Cylinder head 528 ci Hemi. The valve train is very noisy. I dont know when the last time the lash was checked, if ever. I pulled the valve covers to have a look around. The cold lash settings on the intake side were from .015 to .026, exhaust side .014 to .050+. I have no cam spec other than a mechanical roller. Where is a safe place to set them too? I have them all at .015 right now. Valve covers still off.

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Assuming that the lash was set properly, it sounds like parts have worn.

For an unknown cam, aim for 012 int & 014 exh hot lash.

With alum heads &/or block, do this: have tools ready to remove a valve cover, plus feeler gauges. Get engine running, up to operating temp. Then switch off; quickly remove a valve cover, find a loose rocker, & measure the lash. Leave o'night to cool down & re-measure the [ cold ] lash.
Now you know the hot/cold difference, you can set lash cold.
 
The cam card should give you the spec. If you do a search on what folks are doing with al head hemi's your not out of the ball park but maybe a few more thousands on exh versus int.

A stock hemi cast is .028" Int and .032" Exh Cold
 
I'd bet your in the ballpark. Those aluminum heads will loosen to around .018-,020" hot. Even if the cam is prehistoric It won't be that much to tight that it should bother anything.
Doug
 

I'd bet your in the ballpark. Those aluminum heads will loosen to around .018-,020" hot. Even if the cam is prehistoric It won't be that much to tight that it should bother anything.
Doug
Just talked to Indy Cylinder Head. He said hot lash should be .020" for both sides. He would not guess on cold lash. Engine Power just did a piece on hot vs. cold lash. The engine grew about .006" when hot. That was an iron block aluminum head set up. Small block though, if that matters that much? I am between .015" and .016" cold right now. Add .006" and it is right there.
 
Every engine is different. The proper way is do it hot, then go back and see what it is cold (70*).
And you will know how much you're combo changes.
 
Just talked to Indy Cylinder Head. He said hot lash should be .020" for both sides. He would not guess on cold lash. Engine Power just did a piece on hot vs. cold lash. The engine grew about .006" when hot. That was an iron block aluminum head set up. Small block though, if that matters that much? I am between .015" and .016" cold right now. Add .006" and it is right there.
My stock hemi (Ray Barton level 1 cam) minus cam is .020" for both as well. When they get to >.003" off she gets a bit noisy.

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Just talked to Indy Cylinder Head. He said hot lash should be .020" for both sides. He would not guess on cold lash. Engine Power just did a piece on hot vs. cold lash. The engine grew about .006" when hot. That was an iron block aluminum head set up. Small block though, if that matters that much? I am between .015" and .016" cold right now. Add .006" and it is right there.
Set it at .015". Get it it hot and check a couple. Check those same ones the next morning. You'll know exactly how far.
Doug
 
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