I am getting ready to build a header for my old Mini Cooper. There are 3 primary runners that will tie into a single runner which will lead to the turbo. The primary runners will be 1.25". Does anyone know how to properly size the secondary runner?

Here is a picture of the car if anyone interested...

 

Put a B16 in it!

 

www.burnsstainless.com

they should be able to give you some direction.

 

When you say size are you talking about the length of the runner? 3 cyl should be pretty easy to make a turbo manifold for.

 

more than likely the step is no more than 1/8". but like mentioned, burns has a form to fill out and they will set you up.

 

Ok. If I remember correctly the head had the intake and exhaust on the same side (as shown here):



The ports on the outside and the middle are the exhaust and the inner ones are the intake.

The original headers have 3 runners, 1 & 4 being separate and 2 & 3 combined, like so:



I think you could use three runners equal size and make a collector as if the car was a 3-clyinder. You'll be fine!

I don't know if you are a MINI purist but for what it's worth I would put a DOHC Vtec B16/B18 and turbo that, as shown here:



Thread: http://www.16vminiclub.com/forums/viewtopic.php?t=15347

I think you'll have a more reliable/tunable car and the end result, horsepower-wise, would be greater.

Disclamer: All pics are borrowed and shown for reference.

 

Thanks guys... I have been all over Burns SS website, never thought of simply asking them. But I think I have changed the design so that it does not matter. Originally, I was going to have the three runners tie into a single one then go to the turbo. After playing around, my buddy stumbled on a sweet equal length header design that will allow me to run all 3 runners to the turbo. By the way the turbo will be mounted on the side of the engine.



Spiceisler, your mini looks awesome. I am not necessarily a Mini purist and I contemplated putting a busa engine in mine... but the shell was so solid I could not big myself to cut it. If I ever buy another one it will get an engine transplant of some kind.

 

**** the Mini. Lets see the Triumph! lol

 

The mini is not mine! It belongs to user "joecool" on www.16vminiclub.com I just borrowed his picture for reference.

 

I always hated how the ports are on the same side of the head on my Triumph. Even worse that both manifolds are held in place by only 6 studs and what looks like a wind nut to hold both manis with each nut (makes for great fun when the intake and exhaust manifold flanges are different thicknesses)...

 

LOL!!!! The TR6 was my first project.


It got a 302 with a T5 trans and some AC. The few extra horsepower makes it a blast to drive.



Having the intake and the exhaust ports on the same side definitely makes it interesting when laying out the header. The real intersting thing is the siamesed center exhaust port. #2 and #3 exhaust ports tie together in the head and dump out or the single port in the center.

 

A 5.0 in a Triumph. Thats the only way that thing could run reliably. Tuning the carbs on stock Triumphs makes me wish I was hitting my nuts with a hammer instead.