I am wanting to fab my own intake manifold.

I have the aluminium intake flange that is ported with the head ports. The ports are triangular.

Obviously the carb ports are circular.

How would one go about shaping a circular tube into a triangular at the other end.?

Thank you.




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Without cutting and welding?

To answer your question first: I'd use a die in a vice. piece of wood or metal with the desired shape (triangle) cut into it, then cut in half so you can then clamp up the tube and it should then form into a triangle....or there abouts.

My question though, if you're fabricating your own, why triangles?

The intake ports on the head are almost a triangle shape with two sharp teeth sticking out.

If you just cut/blend those teeth out it becomes triangular.

It then becomes the easiest way to port match the manifold

I would make a steel plug former, coat with grease, and push it into the i/d of suitable sized pipe.

A large vice or hydraulic jack / press should do it.




HTH
Paul G

that's sounds good and easy. thanks

[Edited on 16/11/17 by bikecarbfred]

yes, as 907 measure sir cumference and make triangle of same perimeter that tapers into circle out of wood ; then hammer it into the tube. Depending on wall thickness, it should be strong enough. Getting it out may be fun but you could then drill/chisel the wood out or burn in out.

quote:

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Originally posted by 02GF74
yes, as 907 measure sir cumference and make triangle of same perimeter that tapers into circle out of wood ; then hammer it into the tube. Depending on wall thickness, it should be strong enough. Getting it out may be fun but you could then drill/chisel the wood out or burn in out.

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Lmao carpenter

I actually thought it wasn't a bad idea because aluminum is alot softer than the steel.

What pipe thickness would you guys go for taking into consideration it has to be welded to the flange