just both a 352 1962. would like to do a compression test on it !!! what is the magique number ...sorry for my english...tank-you in advance !!!

factorie specs:
220 horsepower
v8-352
bore 4.00
stroke 3.5
compression ratio 8.9

 

According to my 1966 Ford Repair Manual, the cranking pressure for a 352 should be between 160 and 200 psi.

It also states the maximum allowable tolerance between cylinders is 20 psi.

On an engine that old, I wouldn't worry if your results are a bit lower than Ford's spec as long as the engine isn't burning oil. As the rings wear, the comprssion test will show lower results.

However, the maximum difference between cylinders is important. If you have a few cylinders a lot lower than all the others, you may have some valve problems.

In my limited experience, I havn't seen low compression test results from a bad head gasket, so I would say poor results indicate a mechanical problem with the rings, valves, camshaft, etc.

You may want to investigate doing a Leak-Down Test on your engine. It can tell you things a compression test can't.

Leak-down tester - Wikipedia, the free encyclopedia