Re: Big Block Chevy Intake decision
 

Is that a flat tappet speedracer? If so what is the part number and mfgr? I have been looking at a comp cam 11-240-4, 564/567 278/292 with a 112LS. Wouldn't mind checking yours out if you have the info handy.

BT

Re: Big Block Chevy Intake decision
 

bt,

It is flat tappet. The cam is an Isky 280/292 Mega Hyd. (marine grind)

Re: Big Block Chevy Intake decision
 

Do you have the Intake centerline and lobe seperation angle specs?

BT

Re: Big Block Chevy Intake decision
 

At the risk of hijacking the thread, how much can be safely bored on a 454 block? Is it any different for a marine application?

Great info on the intakes everyone!!

Re: Big Block Chevy Intake decision
 

I believe mark IV 454s can go to .120 over, depending on how much hp you are pushing. The wall starts getting weaker and moves more the further you go. Problem with most marine engines (unless closed cooled), is corrosion is working on the other side of the cylinder wall to make it even thinner. There are things that can be done to counter the flexing wall issue, like putting cement in the water jackets to stiffen things up. I run closed cooling, so the .070 doesn't bother me a bit but without it I think I would start getting nervous over .060 over.

BT :cool:

Re: Big Block Chevy Intake decision
 

Does anyone have an opinion on the Isky cam mentioned above? Good, Bad?

Re: Big Block Chevy Intake decision
 

bt,

I do not have those specs, sorry. I remember looking up the cam on Isky's site. I don't believe that they had it there either.