In theory if I was .010-.014 right on lash on the intake would this cause performance issues. Explanation would be helpful.

I'm very far from a guru, but as long as you actually have lash on the base circle, I don't see how you'd cause a problem.

Not sure I understand... when you say right on. 010-014. Should be able to get them within plus minus. 001

But I will say that I doubt many of any people truly understand or ur have the time, or resources to accurately see or understand such a small change vs everything else going on.

When I do my lash regularly as a maint check more than anything. I don't /see the charges. If the car moves. 02 from what I think it should I just adjust for it that day as it could be anything.
That is what time shots are for.

So in theory.. Yes it will matter, in reality you won't know or see it.

My question is if you are supposed to be .026 hot and you are actually .012-.016 hot could you actually close the intake valve late and not get enough compression

Only if the lash was so little the valve never gets back to it's seat.

When valves get hot they can elongate and your lash closes up.....Mostly the exhaust side....way hotter than the intake....

On small engines with solid lifters and very small lash settings this can be a big problem as the engine gets hot.

Usually not a problem on a drag race engine.

It will make changes, probably to small to notice, but I can tell you it will. My engine guy showed me the difference in lash changes with using a compression gauge. Pretty cool stuff.

I know the tighter I run my lash the faster I go, but that is just telling me the combo wants more cam, which it isn't going to get!

As stated a compression gauge wil answer your question. Run valve at .010 and loosen and see what difference you see. Next you can valves at one setting one weekend and provided conditions are close you another setting the next time out.Unless you can actually make ABA test and see.

With some combo's there will be almost zero difference and if combo is off on cam it can make noticeable difference,still not going to be big.

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As stated a compression gauge wil answer your question.

It should be noted cranking compression is that and only that. Dynamic compression at speed is another. An A-B test and your time slip is your best tuning aid.

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Originally posted by Cory:
My question is if you are supposed to be .026 hot and you are actually .012-.016 hot could you actually close the intake valve late and not get enough compression

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Originally posted by Canted Valve:
It should be noted cranking compression is that and only that. Dynamic compression at speed is another. An A-B test and your time slip is your best tuning aid.

^^^ THIS. Tight lash might lower your cranking compression, yet increase your dynamic (actual running) compression, just like when you change cam to one with more duration. Time slip or dyno will show the difference, (most likely very small).

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My question is if you are supposed to be .026 hot and you are actually .012-.016 hot could you actually close the intake valve late and not get enough compression

By comparing the two different lashes, typically when both (Intake and exhaust) are equally tighter by a significant amount, such as what you stated, then yes it can and typically will hurt performance.

If in fact the engine has low or lower cylinder pressure due to a cam that might be mis-matched to the combo, then by adding more intake seat timing can reduce the cylinder pressure even more, and therefor lower the torque output numbers and reduce the torque curve.