How do you tell whats the CC rating of the combustion chambers are. I have a 1988 turbo head and also a 1988 Ranger head. Is it a good idea to put the Ranger roller cam in the turbo head. I am building this engine to run on 108 octane propane fuel and will not be useing the turbo.I will be uping the comprestion ratio to possibly as high as 12 to 1. Are the valves and seats any harder in the turbo head?
If you're wanting to run a high compression engine, go with a N/A head as the chambers are smaller. if you want a larger combustion chamber, try some of the old oval port heads. The combustion chambers are nearly identical to the turbo heads but have the larger oval intake ports. As far as the cam is concerned, what RPM range are you looking at? The Ranger cam has good bottom end torque, but falls off at higher RPM.
Most anything that runs on unleaded gas has hardened valve seats. I think the turbo heads do have harder seats than the N/A ones do, but it still doesn't do them alot of good as they are very prone to cracking from the extra heat generated by the turbocharger.
If it is in good shape, I'd save the turbo head for someone with a turbo car. Good turbo heads are getting hard to find because of the exhaust valve seat issues.