Fan Removal--46 Commodore--New Question

Jim Kilday

Yes, well the magnet was a great idea--so good I wish I had thought of it.



But the head is not aluminum.



How did the aluminum head add additional horsepower and can one of these be found and if so, who might know where I might find one?



Can the existing head be shaved to accomplish the same thing or is there some special alchemy that only an aluminum head will work.



I like the idea of the AL head as it would be considered stock and an additional 10 horses isn't to be sneezed at.



I am thinking about driving the car over to Harkins Machine in Watertown, SD for a complete engine rebuild. At that time Harkin would put an aluminum head on (provided I find one) or modify the existing head (provided that is an option.)



I'm curious about how long it might take to do a complete number on this engine. Assuming Harkin started on the engine and stayed on it with no delays waiting for parts, or other significant interruptions, how long would it take from the time they lifted the hood until they closed it on a "new" engine? The reason I ask this is that I have friends and relatives in the Minneapolis area and can bunk with one of them while I wait. It would save the trip back and then over and back when the engine is completed. We can also catch up on some serious drinking we put on hold a number of years ago while I am cooling my heels waiting for Harkin.



I think I asked before and someone suggested a replacing the clutch whilst the engine is out--is there anything else that can/should be done while the engine is out?



Thanks for your help.



jim kilday

Park_W

Jim, the aluminum head produced more HP by its having a higher compression ratio. The aluminum material was felt to be better at dissipating heat, which would be a little greater with the higher CR. The aluminum heads bring a little baggage with them, in the form of tendency to corrode and being easy to strip the spark plug threads (of course thread inserts can fix the latter problem). You could have something milled from your cast iron head to achieve about the same CR as the aluminum one (has anyone out there determined how much "shaving" is correct practical?)