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My son and I are building 2 460's.....one radical for the strip/some street....one tamer one for the street that I already have cast heads for. I come from the old school (60's early 70's) when aluminum heads were taboo for the street due to different expansion rates of the different metals. Are things different now? My son is insistant on this and I need some input as they are a hellava chunk of change to purchase.
Thanks a bunch, Mark
I'm an old school 70's type too, but it seems new head gasket technology has remedied the aluminum heads on iron block problems.Quote:
Originally posted by 460Cougar
My son and I are building 2 460's.....one radical for the strip/some street....one tamer one for the street that I already have cast heads for. I come from the old school (60's early 70's) when aluminum heads were taboo for the street due to different expansion rates of the different metals. Are things different now? My son is insistant on this and I need some input as they are a hellava chunk of change to purchase.
Thanks a bunch, Mark
Aluminum heads will alway's expand at a different rate than Iron,,,,There are Better gaskets these day's made for just that application,,,,another old trick in the machine shop was to bake the Aluminum head until it warps,,,and then,,resurface it,,,,,this is because aluminum has a memory,,,,when it is warped,,,it becomes Tempered,,,and once Tempered,,it is not likely ever to warp again.
Mark,
Two things still haven't changed since the late 60s and early 70s:
1) The coefficient of expansion for iron and that for aluminum still vary by the same amount that they always have, in spite of advances in gasket technology.
2) Aluminum is still amphoteric, meaning that it readily corrodes in both acidic and basic solution, and corrosion of internal aluminum engine parts exposed to coolant is still as big of a problem as it ever was. Do a web search for DexCool and read a little of what you find.
That said, apparently from what I've read in the forum(s) here over the last couple of days, a lot of people have good experiences with aluminum heads. I myself am very fond of aluminum intake manifolds, and use them wherever possible; however, I still use straight up ethylene glycol like I have been for the last 35 years when I run one on an engine. I know a some individuals may think that unnecessary or silly, but I don't want any nasty surprises when I take one off to get to the lifters, replace gaskets, etc. One Edelbrock Torker is enough of a sacrafice to make to coolant corrosion.
Randy