Re: B Engine with H.C. Head

Posted by Marco on July 28, 1998 at 15:24:13

In Reply to: B Engine with H.C. Head
posted by Jim on July 28, 1998 at 12:12:19

A stock 'A' or 'B' engine will function reliably with a 6.0:1 compression with the following caveat:The engine must be properly rebuilt, and the timing must be handled correctly.
Many "rebuilt" engines have less than ideal clearances in the main bearings, rod bearings, pistons, and piston rings.They also are rarely balanced as well as they were originally.Theoriginal low compression allows for a somewhat "bullet proof" engine even when poorly rebuilt.
If you are running an original 'A' type distributor with a high compression head, proper use of the spark advance is more critical.Many A'ers will simply start the car, advance the lever and drive.With high compression it becomes more important to advance the timing somewhat relative to the engine speed and load similar to what a centrifugal advance distributor will do when setup properly.Many bearing failures are from advanced timing at low RPM under a load.Raising the compression as described simply reduces the margin for error elsewhere but is well within the capabilities of the engine.
My experience is that the aluminum heads require a little more care and maintenance, but also reliable when properly setup.The cast iron heads will likely provide more years of service with all else being equal.The best gasket for general service is the solid grey type without the copper clad.
If you feel any uncertainty about your engine you should consider breaking it in with the standard head and get to know it well before installing a high compression head.

E-Mail Comment to Webmaster