Head cracked???

MA70-3.0GT · 11-26-2009, 01:53 PM

I guess you're right, whatever happens I'm still having the car & whatever it turns out to be is whatever I'll fix.

Just one thing, I did a compression test last night (cold as that's when the problem seems worst, I'll do hot today) and all came back at 145psi except number 5 which was 130psi, exactly 10% so just about within "acceptable" range & not what I would have expected from such an apparently big leak.

I think I'll look into sealing products for the moment (such as K-seal, which is designed with bi-metallic engines in mind) and if the problem persists I may run something like that through the cooling system to try and stop further erosion of the gasket/head.
At least that way I can get some use out of the car & identify/correct any other issues before spending big money on the motor. (If I have to do the HG I'll probably get the head & block lapped & go with the MHG solution with ARP bolts, that way it should last a bit better & I can tune without worrying too much...)

11-26-2009, 01:53 PM	#3
MA70-3.0GT 12psi boost Join Date: Oct 2009 Location: Crewe, England Posts: 356	I guess you're right, whatever happens I'm still having the car & whatever it turns out to be is whatever I'll fix. Just one thing, I did a compression test last night (cold as that's when the problem seems worst, I'll do hot today) and all came back at 145psi except number 5 which was 130psi, exactly 10% so just about within "acceptable" range & not what I would have expected from such an apparently big leak. I think I'll look into sealing products for the moment (such as K-seal, which is designed with bi-metallic engines in mind) and if the problem persists I may run something like that through the cooling system to try and stop further erosion of the gasket/head. At least that way I can get some use out of the car & identify/correct any other issues before spending big money on the motor. (If I have to do the HG I'll probably get the head & block lapped & go with the MHG solution with ARP bolts, that way it should last a bit better & I can tune without worrying too much...) __________________ '89 MA70 Supra GT aero 3.0turbo JDM, Rebuilt motor, K&N intake, 3" stainless turbo-back. New turbo and braided line kit... '89 Honda NC27 400, NC23 cams, open pipe, PC36a shock & possibly Showa USD forks... '83 Yamaha 29R XJ750E-II, number 69 off the line, only runner in the country? Original except Koni shocks '95 Honda PC26 CB500R, Winter hack, hateful, trying to sell it I'm not paranoid, they really ARE after me!!!