i have a fully built gsr block and head. building it for ~450whp.

the block has been cut 1 time.

the head has been cut 2 times.

i dont know how much was machined off... so...

IS A .120" HEADGASKET A GOOD IDEA TO USE IN ORDER TO BEST RESTORE LOST CLEARANCE BETWEEN THE PISTONS AND VALVES?

WHAT IS THE EFFECT ON MY COMPRESSION RATIO?


LETS GET SOME OPINIONS ON BRAND NAMES TOO!!

 

Without knowing how much was milled off you're just guessing.
If your pistons are still below the deck there wont be any interference with valves.
Im in the same position. I just run oem, its fine.

 

i take it a gsr IS NOT an interference motor?

WHAT ABOUT MY COMPRESSION RATIO? I USED A COMPRESSION CALCULATOR AND A .120" VS. A .74" HAD A COMPRESSION RATIO OF ~9.0 VS ~10.0.

 

bump

 

You are making Indiana look like it’s full of a bunch of idiots... ALL HONDA MOTORS ARE INTERFERENCE ENGINES!!!

 

Muckman meant that the piston shouldn't interfere with normal valve movements. Unless you have a crazy high-lift cam, there should be enough room.

However I'd recommend you have a machinist measure the block's deck height, and also CC the combustion chaimbers. That will let you figure out what the compression is, as well as tell you how close the pistons will be to the deck. The only true way to check valve clearance is to clay the motor. Use the middle layer of an old HG, lightly torque the head down, and turn the crank while a valve is fully open. That will give you the minimum clearance. Just remember to calculate what VTEC will reduce the numbers to, or engage VTEC with air pressure via the method HELMS manuals recommend.

As far as brand names, Cometic is all I'd recommend if you *had* to get a non-OEM HG. However, I'd personally rather see a tighter valve clearance than

 

.120" Thats really thick. That will probably drop you just about 2 points in compression!

 

.120" is literally 4 stock gaskets stacked on top of each other, if your motor is hacked that much you need to just start over fresh....

Telling us how many times it was cut is useless info to us, we need amounts that it was cut, .020" off the deck and .010" off the head is not alot, and certainly wouldnt even require .060" worth of headgasket to work.....

As stated above you need to measure everything to determine exactly how much was removed and what your current clearances are.

 

Thanks HiProfile thats exactly what I meant. With flat top pistons I couldnt imagine there being piston to valve contact unless you had a large cam. You need to get it measured to know exactly how much was taken off.

 

whats the process of seeing how much was machined off consist of? i mean how do they do it?

does the block need to be assembled (mine is stroked using an LS crank)

 

Both the block and the head have spots where you can take measurments from to determine what has been removed.... here is where you take measurments from a B-Series head (stock is .040") I am not sure of the stock deck thicknesses.

 

so that low spot in the corner of the head is .040" below the 'deck' of the head in stock form?

is the block also .040"?

 

Correct the head is .040"


If you figure that out please let me know