Aluminum Exhaust?

[Metals406]

I've been throwing around the idea to make an aluminum exhaust for one of my saws. If I'm going to spend the time to tare apart the factory do-hicky... Why not just fab a new one? 3XXX series aluminum is used for radiators, air conditioning condensers, evaporators, heat exchangers and associated piping systems... Just to name a few.

Anyone have any temp readings from their exhaust, after working their saw a while?

 

[ericjeeper]

Aluminum melts at 1200

So if you see any EGTs above that the piston will soon be scored as well.
Snowmobiles have ran aluminum pipes for years.Maybe some steel up close to the head first would be in order.

 

[Metals406]

So if you see any EGTs above that the piston will soon be scored as well.
Snowmobiles have ran aluminum pipes for years.Maybe some steel up close to the head first would be in order.

I think the 3XXX is closer to 1220... And mild steel is like 2500. Aluminum is a great heat-sinc, as I'll use it under thin stainless while welding. Steel at a black heat, is around 500 degrees. I've never seen a chainsaw exhaust glow, and I've cut firewood in the dark.

I like your idea though... Use a thin piece of steel under the aluminum to mount it.

 

[Jacob J.]

Mac kart engines have had aluminum box mufflers since the early 60's and they work very well...

 

[HolmenTree]

My Stihl 090 has a aluminum cast muffler. It is used for one reason [heavy duty and maxium efficiency]

 

[Metals406]

This wouldn't be cast... Actually, 5XXX series is more readily available to me than 3XXX. I think I'm gonna try it.

 

[gink595]

I've been throwing around the idea to make an aluminum exhaust for one of my saws. If I'm going to spend the time to tare apart the factory do-hicky... Why not just fab a new one? 3XXX series aluminum is used for radiators, air conditioning condensers, evaporators, heat exchangers and associated piping systems... Just to name a few.

Anyone have any temp readings from their exhaust, after working their saw a while?

I don't know what my saw ex. temps are but my diesel has a Pyrometer on it and it reaches 1300 F. Aluminum is used in heat exchangers and such to disapate heat. In performance exhausts you want keep the heat, People using header wrap and such to keep the exhaust flowing. Kinda like a cold flue/chimney won't draft right! I'm sure it will work fine it's not like you have 10' of exhaust to worry about. 3000 series aluminum is a fairly mallable alloy, I'd be worried that it won't hold shape with reaching high Ex. temps, like sealing at the exhaust port, which could cause scoring of the piston. What ga. of aluminum are you looking at using? Best of luck!

 

[ShoerFast]

Why wouldn't it work, the first half inch or so is aluminum? (cooled by the cylinder fins)

The internal portion of the duct work should be equally 'divergent' as the ex-port leading away from the cylinder head. Or build a finned aluminum housing around a stainless basket.

If you made it out of aluminum like a conventional muff, with the basket and a exit hole, yes it would melt, or weaken enough to fail. (my bet, try it?)

Build it so every portion has a heat-sink to bleed off any hot spots and it should work.

But my bet?

Aluminum with cooling fins will wight in close to the weight of a conventional muffler?

 

[Metals406]

I can't believe someone hasn't tried this already?? There are a lot of saw builders on here.

Maybe, Dean is it?.. From Wash Pro Saws--would have experimented with it?

What ga. of aluminum are you looking at using? Best of luck!

I use the general rule of thumb--twice as thick as the steel you would use. I think 1/8" would suffice.

I believe that even if it reached temps to anneal the aluminum, it would still hold it's shape... But I need to measure exhaust temps to be sure.

 

[gink595]

I can't believe someone hasn't tried this already?? There are a lot of saw builders on here.

Maybe, Dean is it?.. From Wash Pro Saws--would have experimented with it?



I use the general rule of thumb--twice as thick as the steel you would use. I think 1/8" would suffice.

I believe that even if it reached temps to anneal the aluminum, it would still hold it's shape... But I need to measure exhaust temps to be sure.

I think you can buy those laser type pyrometers that measure temps fairly cheap, I think I seen them at wal-mart?? You could measure the temp on the existing muffler.
It doesn't surprise me that people haven't made these out of aluminum, alot of people can't tig weld or don't have access to a tig. Plus aluminum is much more harder to deal with, especially keeping the joint preps clean, if you do a lot of aluminum you know what I mean. I would think .125 would be okay maybe doulble it at the exhaust flange for good measure!!

 

[Metals406]

Also, does it have to have factory volume? What about a small chamber, and the correct port opening to keep back pressure?

Something like a header on a car/truck.

 

[Metals406]

I think you can buy those laser type pyrometers that measure temps fairly cheap, I think I seen them at wal-mart?? You could measure the temp on the existing muffler.
It doesn't surprise me that people haven't made these out of aluminum, alot of people can't tig weld or don't have access to a tig. Plus aluminum is much more harder to deal with, especially keeping the joint preps clean, if you do a lot of aluminum you know what I mean. I would think .125 would be okay maybe doulble it at the exhaust flange for good measure!!

Yeah, I was thinking thicker at the jug.

 

[gink595]

Another thing to think about when laying out your design, try to keep welds to a minuim. With all the viberations a chainsaw makes and the way aluminum will crack at the welds, it might self destruct. Ive had that problem on a motorcycle exhaust. Probably more bends the better.

 

[Metals406]

Another thing to think about when laying out your design, try to keep welds to a minuim. With all the viberations a chainsaw makes and the way aluminum will crack at the welds, it might self destruct. Ive had that problem on a motorcycle exhaust. Probably more bends the better.

I was just sitting here thinking about how to throw it together... I'm going to get some temps before I move forward.

This will keep me up half the night now LOL :monkey:

 

[Jacob J.]

It doesn't surprise me that people haven't made these out of aluminum, alot of people can't tig weld or don't have access to a tig.

That and the fact that it's labor-intensive to make a muffler out of aluminum.

 

[Metals406]

That and the fact that it's labor-intensive to make a muffler out of aluminum.

And some would say porting, or custom dogs, or any mod is labor intensive... And probably a waste of time... But then again, they haven't been bitten by the Arboristsite bug.

 

[gink595]

Here is a exhaust experiment that I tried on my bike, didn't fair so well on the dyno, I had proably a 100 hrs on that stupid thing, ended up switching back to my stock exhaust, it ran best with it, ya never know until you try!!

 

[Jacob J.]

And some would say porting, or custom dogs, or any mod is labor intensive... And probably a waste of time... But then again, they haven't been bitten by the Arboristsite bug.

This is true, and when I was younger and had a lot more time to waste, I would have even argued that my powder-coated dawgs and muffler made my saws run better. :censored:

 

[Jacob J.]

Here is a exhaust experiment that I tried on my bike, didn't fair so well on the dyno, I had proably a 100 hrs on that stupid thing, ended up switching back to my stock exhaust, it ran best with it, ya never know until you try!!

That's right and that's the one of the ways we learn this stuff. It looked great though and you did good work.

 

[gink595]

And some would say porting, or custom dogs, or any mod is labor intensive... And probably a waste of time... But then again, they haven't been bitten by the Arboristsite bug.

I'd give it a go, My last post wasn't trying to be discouraging, so here is a succes story, this one was off a guys bike that wanted his cat removed, so I made this section for him, if memory serves me it made 6 hp more overall after some remapping on the injection!!! Go for it!!!