So I go to my new machinist yesterday to pay for my 235 head. He had to surface the head another .010" cuz he said it was .006" warped. I asked what the hell, as the head had been cut .030" in '97. Shop says that the head had been shaved on an old machine, which introduced a "bow" into the center of the head due to a worn surface machine. OK, I'll buy that.

He removed the umbrella seals and installed new o-ring seals. He said that was correct for a street engine. Said valves, guides, and hardened seats done in '97 were OK.

He also said that the head was trying to drop a valve. HUH? I said. Seems that the Comp Cams inner/outer springs I was using didn't fit the stock valve retainers correctly. The inner spring was grinding away at the stock retainer, and could cause a lock to pop loose. So he installed the correct Comp Cams retainers with new locks, machined the spring seats in the head, ground the valves, surfaced the valve stems, checked the springs, and set the installed height on all valves.

So if any of you guys use dual-wound valvesprings on your 235/261, you have to use the Comp Cams retainers and have the spring seats machined to accept the inner spring. Or risk dropping a valve. How many of y'all knew that one???

He is also going to CC the head so we'll know the compression ratio.

Question- My '54 (pre-898) head has now been shaved at least .040". How will this affect my valve-to-piston clearance and valvetrain geometry?

Chip

Preaching the Hot Rod Gospel according to the 4-stroke apostles:

Suck, Squish, Fire and Fumes