What would be the best way to transition from a rounded rectangular exhaust port (SR20DET) on the manifold flange to a round runner tube? This isn't normally a problem for people using 1-1/2" runners but I want to use 1-1/4". The perimeter of the exhaust port is ~4.9" and the perimeter of the outside of the 1-1/4" runner is 5.2 but the mild SCH40 is so thick.

Should I shape the runner into an oval shape to better align? cold or hot?
Should I purchase concentric transitions?
Should I fab a transition by chopping up some pieces of pipe?
Just weld it and blend the transition with a grinder?

Any other ideas?

Thx,
Mike

 

Use shed 10?

 

I've shaped sch10, it forms pretty easy.

 

With an anvil and 5 lb sledge it ovaled a lot easier than i had imagined. I guess I'll just shape it the best I can, weld and blend.

 

Oval and Blend will do the job pretty well !
I have done several manifold that way, same thing for the collector.

Sch 40 is thick, but if you use a carbide bit, be carefull not to remove to much material in the tube, instead, make a nice thick weld around the tube and head flange, it will give you a strong joint even if grinded.

good luck !

 

Typically it is easier to bend / shape then what you would think.

 

http://www.turbo-flanges.com/product...75aad5b623e402

 

^^^^^Holy crap, thatd be the best $55 you ever spent! lol

 

No joke, those flanges are nice. It looks to be the same company as SLS. I get my flanges from them, price is identical, fast shipping.

 

SLS flanges are amazing.