Model A Engine Question

I have a stock Model A engine with a "high compression" head. Checking the compression with my guage, I read between 60 and 65 psi in each cylinder. What should it be? http://mccainautomotive.com/LawerencetheCar.htm

 

Years ago I had a Model A with high compression head, dual carburetors, etc and I had a little over 150# in each cylinder. You may be a little low depending on what head, pistons, cam, carbs, etc.

 

I have just spoken to a restorer friend of mine and he tells me a high compression head should give you around 70psi per cylinder.

That is not to say FatFndr<SCRIPT type=text/javascript> vbmenu_register("postmenu_5301933", true); </SCRIPT> comments are incorrect as other factors will make a difference as well.

However as a general rule with nothing else done 70psi is roughly what you should end up with.

 

FatFndr is that you Ed

I agree it all depends which head, pistons, cam. My hill climb A has 160lbs compression.

 

So long as all the cyl's are within a few pounds of each other, I'd say your good to go.

Naturally, that assumes the engine hasn't been sitting outside in the mud for the past 30 years

Also, keep in mind that 6:1 was considered "high" compression when that engine was new.

 

My old Motors manual says 65-70 PSI, wide open throttle and engine at normal road temperature, stock engine, Greensboro is less than 1000 feet elevation so that won't be a big issue.
I would suggest that a leakdown test may be more productive.

 

Thanks for the help. Jeff