Anyone ever build/run header pipes made of aluminum ? Or is it impractical idea ?? I’m thinking alum header on an alum block. The other day, I heard that some newer car was equipped with alum exhaust headers, maybe just dreamed it. With all the modern types of alum available today, just may be possible ?
From a quick google search. The melting temperature of aluminum is 1,221 Degrees F. Cast iron melts at 2,100 Degrees F, or a little higher, depending on the casting mix. I suspect that if the engine is run hard, the aluminum will melt. I also suspect that the aluminum will quickly corrode away at normal exhaust temperatures. I am an electrical guy, so stay tuned for expert comments in the morning.
Impractical... and it has been done, although before you think. Pontiac cast a handful of aluminum 'headers' for their factory A/FX program in the early sixties but they were short-lived. Couldn't take the heat, even in the short time duration of drag racing. You may be able to get the 'look' though. Before ceramics and powder coating, the premium coating for headers was 'aluminizing', literally a spray-on coating of vaporized aluminum. Major drawback was it stained rather easily, and headers would still rust... from the inside out. There must somebody still around that still has the equipment to do this.
You can get boat, water manifolds in different engine makes. They might look odd on a car though. I think someone cast up some Studebaker R3 manifolds in aluminum. But actual aluminum tubing to be used for headers... Might work for around town driving. but any fun/freeway or racing, na... Would have holes burned in the first bend in no time. Mike
Even back in the good old days when airplanes had headers they were inconal. Aluminum loses strength with heat. There is a good reason you don't see it in use for headers. Use stainless if you want bling.
Thanks all for your input ! If I want bling, I would have iron header ‘ceramiacoated’.....inside and outside, as I’ve done in past...works great ! However, I’m thinking weight savings, ergo alum question.
Thanks for the advice, but having a bout with cancer right now, and a couple of recent stays in hospital has covered all of those bases...i.e.-skin/bone right now ! Hey, life is good and I'm still here....but alum is out !
and if they dont melt ? you see aluminum pistons run in almost every engine.. they are thicker then pipe though and can dissipate the heat through the skirts. and you see aluminum heads but they are water cooled. the issue i would say is they will break at the flanges and or collector welds.. the extreme heat cycles on thin wall header pipe material will make the temp differences from flange to pipe detach from each other. and at the welds area. and they may sag or bend easy when at temperature.. thats most likely what i think would be the issue.
Chrysler’s 3.6 liter in my Jeep and I think in all their minivans the header is cast as part of the head.
Actually it was the Super Duty cars not HO's. Anyway it's rumored the original ones would literally be dripping at the end of a 1/4 mile run. A place called RamAir Restorations is reproducing them currently in modern aluminum specs and claim with an internal coating they can be run on the street with no issues. I plan to use a set on our '61 Catalina but'll be another year or so before that happens.
Pistons don't melt because there water and oil cooled. Take away the water and oil and see what happens. Heads are air and water cooled. Samething
There are plenty of water cooled 2-stroke engines out there, and the ones that aren't water cooled are air cooled. And that little bit of oil film between the piston and cylinder in 2-stroke and RC engines plays a huge role in transferring the heat from the piston to the cylinder. And as mentioned earlier, the fresh intake charge also cools the engine a bit, especially in those 2-strokes with good scavenging. Then of course you have the big supercharged 2-strokes (Detroit Diesel among others) that blow a lot of fresh air through the cylinders on each cycle.
Another reason (of many) why aluminum headers and pipes are a bad idea is that heat passes through aluminum easily and quickly compared to steel. This cools the exhaust gases thus reducing gas velocity and reducing the scavenging effect of headers and pipes. Wrapping and coating exhaust tubes keeps the heat in and the gas velocity up. Aluminum exhaust components therefore reduce engine efficiency.