Valve gap and compression

[Sweetbabyjane1]

In the process of adjusting the valve gap we noticed the rocker arm screws have to be retracted quite a bit. See photos. The original heads were replaced with a rebuilt set. We suspect the new heads were machined causing the cylinder and head assembly to be shorter therefore making the push-rod extend farther into the valve rocker assembly. Is the operation of the rocker compromised or should we be worried that compression ratio is now too high? Are there any other issues we should be concerned about?

As always your valuable information to help with this restorations is greatly appreciated. You all have been great!

[VW_Jimbo]

Can you get a .006 through there? Is the stem being hit off center? Does the engine turn over without any interference issues?

Those would be my questions. If you think that they need to be further from the valves….. it may be the cylinders are too low. Run your numbers through CB Performances compression calculator. I typically run that during my pre assembly mock up. That way I can get shims if needed, or machine some part before final assembly.

http://cbperformance.com/v/enginecalc.html
_________________
Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[Sweetbabyjane1]

Yes to all your questions. We are concerned about the compression ratio being too high or any other potential issues.

Thank you for all your help, as always.

[VW_Jimbo]

What is your cylinder diameter?

What is the stroke of the crankshaft?

What is the interior volume of the cylinder head combustion chamber? If you are unsure how to measure it. I did a brief write up of it in my 2127 engine build, on my 70 Bug.

Here is an example, from the Cb Performance page.

_________________
Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!