So I have a b18c block with wiseco pistons k566m815 that call for 11.8 with a gsr head. Now I'm wanting to put my b16 head with ferra flat top valves on this block. What will my compression be with this head? What head gasket should I use cause I'm trying to get 12.1 I really appreciate your help.

 

The B16A cylinder head will make approximately .3 LESS compression than the GSR head does with that piston/block combination. Now, if you add back in the additional compression usually created by flat faced valves, which typically is about .3 of a compression point, you basically get back to where you started.

The difference between 11.8 and 12.0 compression is so small... I would suggest you run what you have. A thinner head gasket can help you achieve the 12.0:1 compression goal but you will lose some quench area which hurts performance.

 

Okay cool. I was thinking of running the 2ply mugen head gasket to get that number back to 12.1 which was my overall goal. I got a guy that is doing by head talking about the importance of getting the quench on the valves just right for good mid range power. Basically my ferra valves keep me as if I had the gsr head on it.

 

http://www.zealautowerks.com/bseries.html

Maybe this will help.

I've found that with Wiseco pistons, the compression heights tend to be too generic, thus allowing the use of the same piston for different B block applications.

But it does somewhat interfere with squish clearance. Quoted compressions aren't always correct.

Using this calculator, you might find that you're not at the compression you think you are anyway. A quick calculation on your current setup, as per this calculator, b18c block, gsr head, wiseco dome 5cc, compression height 30.1, yields a compression of 11.3.

 

Yeah and I will be running the head off my b16. They only option is to shave my head then cause a 2 layer gasket won't get me there.

 

Swapping to a b16 head, with a 2 layer gasket will get you to 11.25, a little under where you are now.

If this calculator is correct, you would need to shave down 0.025" to get to 12.

Personally, I hate shaving the head. Much rather control cr via pistons.

 

I have ferrea flat top high compression valves so that will get me to like 11.5 I don't want to shave my head either. I thought these pistons would get me there without shaving the head

 

Your first step should be to take actual measurements to find your true compression ratio. Measure your deck height along with the other variables and CC your chambers . You will be surprised how often the numbers don't match those of the calculator. Another option if your compression falls short is to weld the quench pads onto the b16 head.

 

Just run 11.8:1 and call it a day bro. That's plenty of compression... what cams are you running?

 

Yeah that's what I figured I would do. I don't want to shave my head cause now I'm going to have it port and polished and i would hate to loose that money if something went wrong. I will be running pro2 cams in it. I'm still thinking on whether I should run the 2ply head gasket. I guess I will see after I check my p2v clearance.