Im gathering all my parts together to build my new plane. I have a MVVS 45 MG with the MVVS tuned pipe setup. The header that comes with this thing is way too heavy. I know they make lighter stainless headers, but my question is will an aluminum header work. The engine head is aluminum and the pipe is aluminum. Why cant the header be aluminum. I have access to aluminum tubing and a TIG welder and pipe bender. I just want to know the drawbacks before I go wasting alot of time on something that is a lost cause. Thanks in advance.

The first part of the header will get quite hot in gas engines, even up to the point that aluminum slowly turns into dough and looses too much of it's strength.
There is nothing against a good experiment though , But I think a thinwalled stainless steel header will be better if you need to minimise weight.

I don't know about the aluminum in the Netherlands -
The stuf here in the Hew Ess Hay looses about 50% of it's strength at 500 f- rough estimate .

How much strength is retained when temperatures reach 570 degrees F (a steel header turns into a saturated blue colour at that temperature)
Four strokes get much hotter, but two strokes?
If a steel header turns grey, that would be 750 degrees F.

So an aluminum header is out of the question. I was curious because the cylinder is aluminum and it is the same temp as the header at the exhaust outlet. I really dont think it would be worth the trouble anyway. I just thought it sounded like a good idea at the time. Plus Im not a weight freak, I just thought it would be a cheap easy way to reduce the weight. But if the aluminum is too soft then I wont worry about it. Thanks.

3W makes aluminum headers, I have one. Not really sure if they are that much lighter, really thick walled.

I think I may just use the stock one. It is on a Aerotech Yak. My goal for this plane is 15.5 pounds. The prototype was 16.5 with a DA on cannister and 2 flight pak batteries and aluminum tubes and gear. I save 5 oz with just the engine and can save another half pound with carbon parts. If I end up being 2 or 3 oz from 15.5, then I will probably order a thin walled stainless header from KS or something along those lines. Thanks.