Let me repeat this for the umpteen-th time; the most important factor in adjusting lifter preload is to insure the lifter is riding on the base circle of the cam lobe when ZERO lash is found.

If the valve is open, even a little, the lifter cannot be on the lobe's base circle. Overlap means both valves are open, which means neither lifter is on the base circle.

As cam duration and LSA are changed from stock, overlap most often increases. That means that when the piston is at TDC there's a much greater chance for both valves being in overlap.

Ever wonder why the TDC method isn't recommended by the cam companies?

So I distrust the TDC method of finding ZERO lash.

Jake

 

No idea why we got off on setting lash. I am bringing up TDC for valve spring removal.

BTW, I don't use TDC for setting lash.

 

Oh, I see now.

I thought your were referring to the TDC method for setting lifter preload. That's the term (TDC method) most commonly used when adjusting preload not removing valve springs.

I misunderstood what you were referencing.

Jake