Max cam lift for 383

[sicksatellite]

hey guys, whats about the max cam lift a stock '69 383 can take without tagging valves? nothing specific, just generally.

 

[Cranky]

The engine still has the factory pistons in it or was it rebuilt with 'advertised' 10-1 pistons?

 

[sicksatellite]

it's got the "10:1" pistons i believe, and 906's

 

[Cranky]

'Advertised' compression ratio is usually way less than actual. The only way to buy pistons for a rebuild is to know what the compression height is. That's the distance from the pin center line to the top of the piston. If the pistons are down in the hole (factory ones were up pretty good), you have lots of room but the best way to know exactly how much you have is to check it with an indicator. This is done using a light weight checking spring and rotate the engine through it's cycle. Without knowing exactly what pistons are in the engine, that's the best I can tell you......

 

[sicksatellite]

Yeah I know that stuff, I was just hoping for a guesstimate. I was looking at some cams with about .500 lift.

 

[Cranky]

I really liked the old Mopar Performance .509 in the low decks but with pistons that come up close to TDC, they better have valve reliefs.....

 

[sicksatellite]

hmmmm....i guess I'd better rip the engine out and do some checking on it before I go cam shopping then. Thanx Cranky

 

[Meep-Meep]

I have a .528" in my 383 with zero deck pistons and I had to cut a valve relief for the intake only. A .474" cam should go in with no mods to the pistons but like Cranky said, better check.