I picked up a pair of fully P&P stock heads. My questions is since stock heads have a 58cc and my heads checked out 52cc how much do I need to mill off on the intake?

Thanks,

Jody J.

 

you should be ok with the stock untouched intake, many run them this way wiht shaved heads

 

But the intake bolt holes do not line up.

 

http://web.camaross.com/forums/showthread.php?t=285544

weird that you are having that problem, my heads are down to 52cc also and i use a .026" thick head gasket and had no problems with my stocker

 

Thanks for the link. I try a dry run and check the port alignment with a mirror.

Jody J.

BTW, what's your compression ratio? If I calculated mine right, with a zero deck, .049 head gaskets, 52cc heads my 355 should be around 12.3:1. Does that sound right?

 

i calculated mine awhile back and if i remember right i think it came out to 11.6:1 with stock deck and heads milled .010" with the .026" gasket

must be the zero deck thats causing your problems

 

JodyJ,
I'm the one that started the other thread. This intake has been a real problem for me--very frustrating when you're expecting it to bolt right up . I just got done bolting it up after 2 days. I ended up elongating the holes with a long round file--didn't use a drill bit because I thought it might take off too much too quick. If you do this, go in from the top and angle straight down. I made the mistake of starting from the bottom because it was easier--had to go back and correct the angle of the hole from the top....

Good luck with yours--let us know how your ports line up.......

 

Here is something that might help you guys.

"Whenever you remove material from the combustin deck surface of the heads, you obviously shorten the head, which can affect the sealing surface angles between the intak manifold and the cylinder head. If the resurfacing process removes up to a max. of about .019" you will likely be ok. If you remove .020" or more from the combustion decks, corrective material removal from the intake port deck and intake-to-block rails will be nesessary. Here's a handy reference to use if you need to match the intake angles.

Consider the amount removed from the combustion deck and multiply this by a factor of 1.2 in order to obtain the amount that must be removed from either the intake manifold mating surface of the head orfrom the intake port deck of the intake manifold. So, if .010" is removed from the combustion deck, you need to remove .012" from either the intake side of the head, or from the intake port deck of the manifold.

You also need to remove material from the front and rear rail surfaces of the intak manifold, where they contact the block (since now the intake will sit to high to allow proper sealing at the port decks). Based on the amount of material you removed from the cylinder head combustion decks, multiply this by a factor of 1.7 to abtain the amount of removal needed at the intake manifolds front and rear rails. If you milled .010" from the heads combustion decks, you would need to remove .017" from the intake manifolds front and rear surfaces.

Combustion deck removal amount X 1.2 = Material to remove from intake port side.

Combustion deck removal amoutn X 1.7 = material to remove from intake manifold front and rear rails."

Wow, that was a lot of typing but should solve your problems though. I took this info from a book.

"How to Rebuild Small-Block Chevy LT-1/LT-4 Engines" by Mike Mavrigian

 

JChevy,

Thanks for the info. So if stock is 58cc and I'm at 52cc, then I would take .006 (per cc) multiply that by 6 which equals .036. Then I could use the formula

.036 x 1.2 = .043 material removed from intake manifold port sides.

.036 x 1.7 = .061 material removed from intake manifold front and rear rails

So would I take that much material off per side or .043 total?

Thanks,

Jody J.

 

The way i understand it is that you would take it off per side, but i am not 100% positive so get a second opinion.

This may qualify as a thread for the advanced tech forum.