A few years ago we made some Wiggins couplings for water plumbing.
These are widely used in airliners and military aircraft as well as Formula
1
race cars. They are highly reliable, long lasting  and quick to take apart.
They must be tig welded to aluminum tube. If you buy the race car versions
they are about $100 each. We simplified them by doing away with the outer
trick clamp and used a mundane hose clamp instead. We also standardize on
1.5
inch OD aluminum tubing for water plumbing. That would be the only size we
would make.

We are thinking of making another batch but we would need to make at least
50
sets. Is anybody interesting in buying some of these? My guess is they would

be half the price or about $50 a set.

Paul Lamar

Can you guesstimate how many a typical installation would require? I"m in,
just not sure how many would be necessary.
C. Smith

You have to layout the cooling system you are using. Refresh my memory on
the
type of airplane you are building and I will dig up some cooling lyouts for
it. Then it is up to you to decide what you want to do.

Paul Lamar

CH640 13b p-port double pass radiator, not sure about bottom or side cooling
yet.
C. Smith

I don't have a firewall forward layout. Send me a sketch of the firewall dimensions showing the prop center line position and the distance from the firewall to the prop flange and I'll do a 3D to find out what fits where.

BTW Since we learned how to get epoxy to stick to aluminum I think we can make wiggins that bond on to the tube. Cheaper than tig welding.

Paul Lamar