Yeah, sometimes it can take tens of thousands of miles for the gasket to tear apart. If it's not a daily driver or you don't put a lot of miles on it you might not have a problem. The graphite coated gaskets were used to get factory engines through the warranty period. BTW, to clean the grahite off of the head and deck surfaces I use a rag soaked with acetone, takes it right off.
That'll work to get it off. I just don't prefer them because 1) you can't reuse them 2) i don't like taking the time to do it
Okay... Say I agree with you for a moment. How much more power? I will not wait for a response to debate The weight loss will give you what amounts to a 7 rwhp gain, or an effective 9 hp at the flywheel. If I agree with your premise, even you have to admit that iron will not give 9 hp over aluminum on the merits of composition alone. Then you have to look at the fact that with the equal compression and cam specs you mention, aluminum will run an additional point of compression on the same fuel. You could also run additional timing, or save money on forged pistons if you car is a street machine. In order for iron to make more power, your engine must run hotter... there are just too many 'cons' to allow this over weight savings and running a cooler engine. My .02 Dave
I think the fact that what I consider a mild set up in my car ran with every similiar car that had aluminum heads at the round up speaks for itself and I got the videos to prove it.........lets go racin sometime Edit not to mention I drive my car 3days or more a week and it can go faster with steeper gears as I choose to run 3.40s and I could add a bigger cam...... I like aluminum heads too but I have had better luck with my cheapie 750.00 roush 200 heads..........if you got the money to spend on AFRs etc kudos to you. I'm not debating talk is cheap You could come to the roundup next year and prove me wrong. WIn or lose it will be fun.
Generally iron heads are considered more thermally efficient than aluminum. The aluminum dissapates more heat away from the combustion chamber and into the water jacket and airstream. That heat is wasted rather than used to push on the piston. You keep more heat in an aluminum head by running more compresssion. It's not so much that you "can" run higher compression with aluminum heads vs. iron heads, it's more like you "have" to in order to retain the thermal efficiency. Most aftermarket heads are aluminum because it's a less expensive material to cast and machine. Machine tooling and molds last many times longer working aluminum and the time required is a lot less.
