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Heya.

I was looking over my PVC mock-up of my turbo/EFI intake manifold, dreaming about the days when I could actually afford a welder... and an idea hit me.


Is there any reason you couldn't make an intake manifold out of brazed copper?


The copper would be easy to work with.. the brazing isn't tough, and the tools to do it are CHEAP! Everything you need can be purchased at the local home improvement / hardware store...

(This is just going to be the center manifold section, and some funny shaped connecting pipes on the intake, nothing on the turbo header itself or the exhaust side).

Am I out of my mind, or would this be an excellent low-cost way to build a DIY manifold??

- David

I think it could work well but I am not sure how the copper will react with fuel - corrosion?

check out the guy who built the intercooler out of copper plumbing pipe on here

Now I'm no expert on metalurgy (or any thing for that matter) but I have heard copper can "work harden" from vibrations like those from an engine. This can lead to cracks and leaks.
A guy doing a custom MegaSquirt install on a Jag E-type was going to do his intake and fuel rail plumbing from copper, but was advised otherwise by some steam engine guru.

John H

just use rubbermounts, and boots so everything can move as it warms up! Why not test it ? It can't be that expensive!

Marty-
I'm doing a blow-through, using injectors in the end castings. Other than a bit of the fog traveling back up into the center, it shouldn't be seeing much fuel. I did a quick search on the internet and couldn't find anything about corrosion problems... then I remembered that people are using copper head gaskets! So... I *think* I might be OK there. More research needed though!

mschilling-
That was the thread that bumped me over the edge, actually. Crazy looking engine, but definitely had some "new ideas" to it!

John-
Interesting. I'll have to research that as well. I don't think it should be a problem here- the manifold will be rubber isolated on all sides (since it will be the center section).. Maybe checking for cracks would be a periodic maintenance item? I'm not going to use the copper for anything fuel related, and the manifold will only see pressures as high as the turbo puts out (which will most likely be under 15psi for my engine)... so not the 70psi fireball that a busted fuel rail would have!

jonas_linder
Thanks for the suggestions! I'm definitely considering testing it here!!



Another thing I thought of last night- it sure would polish up nice. You see lots of chrome at car shows, but how much COPPER under the engine bay??? Thanks for the help, guys.

- David

My take is, do it, and if it doesn't work, we'll all learn something.

- Scott

My fuellines from the tank is in copper! Corrosionen should not be a problem (didn't think about that before

edit. And I'm running 3bar basepressure and it's 1:1 with boost.. so they can manage at least 4bar! (1 bar = 14.7 psi)

I have been brazing copper pipe for years on refrigeration lines. The torches at your home improvement stores will work for soldering with plumbing solder. They are usually too low powered to solder any pipe larger than 1" without some difficulty. You will not be able to maintain enough heat to braze just using a propane torch. Acetylene will get hot enough and with the size of pipe you will be brazing it would take oxygen also.
Copper will suck up the torch heat very fast. I use Sil-Fos brazing rod as it is very user friendly.
Welding copper is a whole other animal. The only way I have seen that succeed is when a guy used a Tig welder with Helium gas and real high amps.
Have fun.

That post is nearly 20 years old brother. I don't think he's gonna get it done any time soon. Although i do think it's a creative idea and i pondered it myself. I have no problem with welding, but my car is copper color and i thought it would be cool to do something like that. Polish it and clear coat it etc...