[bgreen63366]

I have a .040 0ver 350 with 4 valve relief pistons that are .015 in the hole. A set of old 90's dart II sportsman 64CC heads that have not been milled, I am going to a .015 compressed head gasket to reach 10.77:1 cr. My question is, if I go from .039 compressed head gasket to a .015 gasket, should I worry about clearance? If anyone needs more info, please let me know.


Thanks,

Bill

[ace's68]

What is the lift of the cam? You should always check piston to valve clearance, it is easy and can save tons of money. If the lift is below .500, most people don't worry about it, but if the cam is installed wrong (which isn't likely) the valves could hit the pistons.

If you are too close and don't want to loose much compression I would use a .025" composite head gasket from fel-pro, it will seal well because it is composite and is the thinnest next to a .015 that is not shim steel. I personally don't feel like a .015" piece of steel will seal anything that is not perfectly straight, or milled properly after the block/heads have gone through heat cycles.

FYI I used a .025" head gasket, .015" down in the hole, and a .500" lift cam, didn't check clearance and nothing is hitting.

[bgreen63366]

Cam is 272 / .454 but I plan on upgrading to a diff later. I was looking at a comp 292/
.501 cam a little later.

[Steptoe]

Basically the same as my 40/100 over and small chamber 202 heads
Im running 512 lift block has been shaved 2x cant rem but theres about 10 to 15/1000
Heads planed and works out to just ubder 11:1
The cam is advanced 2 degs
NPs ...cant rem the clearance valve to piston but there was heaps so was not a concern when we dumbied up without a head gasket.

[bgreen63366]

Good info, thanks you guys.

[bgreen63366]

Originally Posted by Steptoe

Basically the same as my 40/100 over and small chamber 202 heads
Im running 512 lift block has been shaved 2x cant rem but theres about 10 to 15/1000
Heads planed and works out to just ubder 11:1
The cam is advanced 2 degs
NPs ...cant rem the clearance valve to piston but there was heaps so was not a concern when we dumbied up without a head gasket.

You have an awesome car by the way.

[fatblock]

Lift would be the least of my concerns..p/v clearance is closest +- of tdc during the overlap period.For a street deal with steel rods...080" on the intake and .100" on the exhaust is a safe bet.

[Steptoe]

You have an awesome car by the way.

Thanks..is by no means perfect but hey its a nice daily driver of nearly 30 yrs,and scrubbs up well for a 'rod show and shine...pulls the punters but not the prizes lol...Im happy

[Steptoe]

You have an awesome car by the way.

Thanks..is by no means perfect but hey its a nice daily driver of nearly 30 yrs,and scrubbs up well for a 'rod show and shine...pulls the punters but not the prizes lol...Im happy