question about my set up

[Guest orangebeast]

so i have a 1972 datsun 240 z and just bought a 1983 280zx motor with the f-54 block and i was going to use that with my e88 head but i dont know if its a good idea, someone told me that it wuold create to much compression is this true

[naviathan]

No it wouldn't create too much compression. You sure are getting around. The only thing I would be concerned with is the valve size, which you said over on zcar.com that you would be using valves from the ZX head which are larger. You can get some nice stainless valves from arizonazcar.com that might be better suited. But, as I said before, use an aftermarket engine management and you can tune everything to work together properly and run like a raped ape.

According to the Z Calculator (which isn't entirely accurate, but gives a round about number) the resulting compression ratio would be 8.28:1, which is more than manageable. You go with flat top pistons and it's up to 9.8:1 which is getting more into the high octane area and watching clearances very carefully.

 

BTW, welcome to hybridz.org and zcar.com. Never did give you a proper welcome over there either.

[JMortensen]

Yeah, you don't want to use any old ZX valves because the ones that came in the P79 and P90, which is most of the ZX's, are actually shorter than the earlier valves. You need valves from an N42 or N47. Same diameter as the ZX valves, same length as the E88 valves. Most stainless valves are N head valves.

[naviathan]

Good point about the valve length, I forgot about that.