The Project Pad

Some car parts are projects all by themselves!

I am modifying this 20vt EM in part to see how far the stock manifold can be taken, in part because I would like to do an upgrade to my 200Q 20v in the future, and in part to test and expand my cast iron welding skills.

First off, I know that the factory manifold will always have limitations compared to a properly designed tubular header. I'm not deceiving myself into thinking that this manifold would match or outperform a header. That's not the point of this exercise. I will be flow testing the manifold when it is finished and comparing it to a stock EM. Dyno results on a car are meaningless because so much else has to change in order to use this manifold.

So, here goes...

MoAr!

Taking shape!

#1

#2/5

#3/4

Lots of nickel-99. Here, I am building up the flange to match the Garrett T3 flange.

Grinding down the surfaces-up nickel 99 to match the perimeter of the T3 flange exactly.

Grooves out and welded the inside and outside of the collector crack.

Finalized collector shape.

Inside of collector welded up.

If this isn’t the most extensively worked-over OE 20vt exhaust manifold, I want to see the one that is!

I had some porosity problems on the outside flange welds, so I will be grinding those out and redoing them.

After that, I have to repair the other crack (outside radius of #4 close to the head.

Then I will gasket match the head flange, blend to the best of my ability, and set up a date for flowbenching this against a stock unit.

I have a Holset HY-35 that I plan to bolt to this once ready to install it.

That is a lot of welding done to that manifold. I hope you are pre/post heating, as well as very slow cooling. I welded my single piece manifold a number of years back with good results, at first. It has recently recracked, and it's right along the side of one of my welds around the runner.

I do look forward to your flow bench results. I'm having essentially a stainless log manifold made for factory placement.

Oh, yes. That's cast iron welding 101--preheat, postheat, peen, slow cool.