Thread: 406 sbc w/too much compression!

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I have a 406 sbc I took out of my ski boat. It has 882 heads (1.94/1.50) with a 3 angle valve job and domed pistons yielding 10.5 to 1 compression. I reasoned that with the constant flow on lake water, the cylinder temps would be ok. What I didn't take into account was the heavier load on the engine in a boat versus a car. I don't want to put new pistons in it, as it has few hours on it and the rings are seated nicely. I know a cam with extra overlap will bleed off some compression, but I am not sure where to start. It has a performer rpm intake and cam, but the cam has to go. I ran premium in the boat, but I had to run the timing real light to avoid detonation. Can you guys suggest a cam that will produce good power on the street, yet be ok with premium fuel? My plans for the engine are for a 3000lb car, 3.42 gears, and 28" tall tires. 5 speed manual, no automatics for me! Thanks!

10-1 in a street car is very common and shopuld run great on premium fuel. What are the cam specs, lift, duration, or part number? And also what carb are you running on this combo?

What kind of heads are you running? Aluminum heads transfer heat faster than iron and thus can take more compression before detonation rears its ugly head.

Cam choice... hmmm... what are the specs on your current cam?

-CJP

Current cam is the performer rpm cam, can't find the specs. Is it possible I can use it as is? Heads are the iron smoggers 76cc, 882 is the last 3 digits in the casting number.

Opps! forgot, I haven't picked a carb. Was running a Holley 600, vac secondaries in the boat, but that carb is tired, was going to start fresh. Open to suggestions. There is so much knowledge here, I really appreciate it.