cam size with a decked cylinder

[hippy440]

i have a 440 with thin base and head gaskets and the cylinder decked .030 with an xr 440 cam. how much bigger of a cam could i use with out clearance problems?

[400exRacerX]

What do you meen a bigger cam? You meen a more aggressive cam with a bigger duration and lift? Having a thinner base and head gasket and a decked cylinder shouln't effect the type of cam you put in. That should only affect your cam chain tension.

there really no way to know for sure . unlass you find away to measure your valve clearnce

I don't agree with the first response at all, the cam lift and duration are very critical when you shave the head and/or use thin head gaskets. Also if you advance the cam it will bring the valve closer to the piston before it closes. If the valve floats one time you will bend a valve. I don't know the minimums on clearance for a 400ex. I do know a small block chevy needs .085 on the intake and .100 on the exhaust. I measure these with no head gaskets and have never bent a valve on a motor turning 7500 rpms. hope that helps

You need to have more info to be correct in the answer.

What was the installed cyl. to deck height?

I believe that this was discussed in the post have you decked the cylinder. I remember the desired piston to head min clearance to be .040 but do dbl chk this.

Before you can spec in a cam you need to decide how you want the engine to perform. You may consider more duration in your cam if you are looking for an MX type of use at higher rpm.

I have a similiar set up and am looking for more torque or bottom end so I am looking at a higher lift with a smaller duration. I hope you are getting this as it is a little confusing and cam choice will make a big change in the performance of your engine.

But make sure you check out the above post i think it will answer your question.



I do know a small block chevy needs .085 on the intake and .100 on the exhaust. I measure these with no head gaskets and have never bent a valve on a motor turning 7500 rpms. hope that helps

Its been a while since I set up a small block but wouldnt this be lowering the compression considerably????