anyone use aluminum for exhaust
09-30-2006, 06:14 PM
#5
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Using actual aluminum, as opposed to 'aluminized' steel for an exhaust system would be akin to making your coffee cup out of crystallized sugar, an ash tray out of cellophane, a shark cage from compressed hamburger meat...
(Sorry, got carried away with my analogies)
Aluminum melts at ~ 1,200° F. and exhaust gasses can reach 1,500°F. or more. 'Nuff said...
(Sorry, got carried away with my analogies)
Aluminum melts at ~ 1,200° F. and exhaust gasses can reach 1,500°F. or more. 'Nuff said...
09-30-2006, 06:17 PM
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yeah at the header im sure it would get too hot for it but the rest of the exhaust with ample cool airflow over it? i could touch the rear exhaust (when i had the slp lm on) on my car its very warm but the further away the cooler it stays
hehe Trending Topics
09-30-2006, 08:10 PM
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Shall I spoil the surprise by saying that when I was young and foolish about half a century ago, I built a 2" aluminum system from the header back for an 850 cc. Mini Minor racer, on the assumption that such a big pipe on a little engine surely would run cool enough to survive. Not so! In two laps it was drooping like a clothesline between the hangers and then just puddled at the header end... 
10-01-2006, 10:03 AM
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well i had aluminum egr block off plated on my manifolds for over a month with no issues.. manifolds are also the hottest part of the exhaust.
what kind of motor was it^? i wouldnt dream of using aluminum on my 450cc dirtbike, it turns my head pipe all different colors and is titanium. but for some reason ls1's never seem to get that hot. cars also waste alot more fuel then say a motorcycle engine, my 450cc makes 50+hp a very high number for a four stroke of that size, and doesnt waste much fuel. makeing it hotter. heat is a direct product of power. i know the ls1 makes good amount of power but it nowhere near as efficient.
anyone have one of those point and shoot thermometers? to tell me how hot the collector of there headers get after a few hours of running? for some reason i still like the idea of aluminum tubing. its either aluminum or stainless and i can find any stainless in the size/length i need + its alot more then aluminum.. if the aluminum has chance of holding up i rather use it.
what kind of motor was it^? i wouldnt dream of using aluminum on my 450cc dirtbike, it turns my head pipe all different colors and is titanium. but for some reason ls1's never seem to get that hot. cars also waste alot more fuel then say a motorcycle engine, my 450cc makes 50+hp a very high number for a four stroke of that size, and doesnt waste much fuel. makeing it hotter. heat is a direct product of power. i know the ls1 makes good amount of power but it nowhere near as efficient.
anyone have one of those point and shoot thermometers? to tell me how hot the collector of there headers get after a few hours of running? for some reason i still like the idea of aluminum tubing. its either aluminum or stainless and i can find any stainless in the size/length i need + its alot more then aluminum.. if the aluminum has chance of holding up i rather use it.
10-01-2006, 10:15 AM
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being able to find it is the biggest reason, cant find stainless in 3.5" i need bends and straight lengths ..cost/ weight would be another added bonous. dont have any idea how it would sound or if it would change the sound much.
10-01-2006, 12:33 PM
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You should go down to your local hobby store and get one of the point and shoot thermometer that they use for rc cars. Drive your car around an hour and then take some measurements. Should be interesting...
10-01-2006, 11:22 PM
#15
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Originally Posted by toofazt
You should go down to your local hobby store and get one of the point and shoot thermometer that they use for rc cars. Drive your car around an hour and then take some measurements. Should be interesting...
do you know the price of these things?
10-02-2006, 04:44 AM
#17
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Aluminium would be no good for an exhuast, even if it didn't melt it would expand and contract all the time, this would great fixing problems and over time weaken it.
A titanium alloy could be used, but it's darn expensive. If you need 3.5" tubing just by stright pipe and go get it bent on a mandrel bender.
A titanium alloy could be used, but it's darn expensive. If you need 3.5" tubing just by stright pipe and go get it bent on a mandrel bender.
10-02-2006, 02:10 PM
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Generally you want your exhaust to stay hot, it keeps the velocity up and gets it out the tailpipe. Thats why there are coatings and header wraps designed to keep heat in. The only time I've seen where you want to drop exhaust temps is in turbo applications, particularly diesels. Thats what I've seen working in R&D at Magnaflow.
10-02-2006, 09:35 PM
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Just wanted to point out you certainly do NOT want to drop exhaust temperatures before the turbine side of the turbocharger. It's m-dot (mass transfer rate) and enthalpy (fuction of temperature) that dictate how much power you have to spin the turbine. In a perfect world the exhaust gas would leave the cylinder at temperature X and enter the exhaust head pipe into the turbine side still at temperature X then, leave the turbine at room temperature. It's okay for the exhaust to cool off after going through the turbine but before it enters- the hotter the better (more potential to do work).
Ben T.
Ben T.
