Which will last longer? Iron or Aluminum heads for gasoline engines?

 

id say aluminum heads are just as good as iron.. 4.6 and 5.4 are all aluminum right?? they can take a hell of a beating so... as long as you dont start stripping threads from over torqueing things etc.. i see no difference.

 

The iron headed engines have proven themselves, no? Older engines didn't have the same problems as do the newer, in regards to head gaskets. Two different metals that expand at different temps needs a gasket to accomodate this better than what is on there. Other than that, I think aluminum is the more efficient.

 

All iron or all aluminum is best - when you have iron block and aluminum heads (or vice versa - remember the Vega?) you have dissimilar metal expansion which is harder on head gaskets. I suppose today's technology is a LOT better than it used to be, but back in the days when I was wrenching for a living I hated aluminum anything. Back then, aluminum blocks had iron sleeves, the first siliconized aluminum bores were the Vega engine and it was a disaster.

As far as I know, the reason there are aluminum engine components has nothing to do with efficiency, it's a weight saving thing.

 

iron holds more heat in the combustion chamber. thus making greater engine efficiency. aluminum heads cool off quicker and have lower intake temps. and are moe boost friendly thus making more HP but lesser fuel economy. or atleast thats what the engine builder on NHRA TV says :-p but what does he know...

 

So far I have 208,000 miles on my iron block / aluminum head engine.

Still going strong!

 

Thats pretty much bang on. Since the iron holds heat better you get better combustion which makes more power BUT since they hold more heat you cant go as high of compression without detonating. With aluminum you can go to a higher compression ratio which will also make more power since they disperse the heat faster. So there are pros and cons to both. If your going big power aluminum is probably the way to go as they are lighter, and there are alot more options for aluminum aftermarket heads.

 

you guys really know your stuff. all i could think of was not stripping out soft threads.:o

 

pretty much the guy said if ur gonna spray. get iron heads cause they can handle the heat. if ur gonna go high compression or boost get aluminum

 

Im just a car nut. I used to have a 82 Mustang GT that i spent alot of nights working on. And i ended up upgrading pretty much everything in the car to aftermarket so i did alot of research.