Ford Muscle Cars Tech Forum banner
1 - 1 of 1 Posts

429 Posts
Discussion Starter · #1 ·
A little history....

about 5 years ago I bought the bidget 393 kit from CHP, flat top pistons, .040 over, and topped it with a Performer RPM HCI kit. Got the 1.90 intakes on the heads because they flowed almost as well as the 2.02s and I didn't want clearance problems.

At the time the guy at CHP told me that combo would be about 10.5 to 1 compression. Engine ran great for a while, although detonation prone even with a dump truck advance curve. Fast forward to las fall on the last drive of the year my engine starts making a pronounced slap or knock from a single cylinder, cant tell which, so I parked it for the winter. This spring, problem still there, so I run a compression check. Holes 2 and 3 are at 30psi, the others at 225.

OK, that screams head gasket, but in the meantime I went to the CHP site and with the kit I bought back when, it list the compression ration with flat tops and 60cc heads at 11.75 to 1!

Yikes! No wonder it was a popcorn machine.

So, if indeed my problem was only a head gasket, it seems like I could fix that and the overly high compression ratio with a set of heads with a larger CC chamber. AFR 205s look like an option, but I am concerned about valve to piston clearance. I would really love just to replace the heads and not yank the whole engine to fit with dished pistons.

Any advice on head options?

Also, I was thinking about converting to a hydraulic roller while at it. Comp makes a retro that could use the existing dizzy gear, right? Any advice on grind given the above?

I am not looking to race or even hit 6500 very often, just want a respectable street runner.
1 - 1 of 1 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.