MG_Bryan
MG_Bryan Reader
12/1/11 10:20 a.m.

If I person wanted a header for a certain engine, and nothing satisfactory was available through the aftermarket, how would he obtain a flange to build his own header?

Should I take the exhaust manifold/gasket to a machine shop and just have them cut one out for me, or is there some incredibly cheap, yet effective method of doing this in my garage. No access to a plasma cutter or anything fancy like that.

The harebrained idea is in regards to turbocharging an MG. I realize that's probably going to end in a very broken engine unless I keep the boost pretty low, but I have 4 and half of them sitting around and I'm looking for something that will make more than 50 horsepower while I slowly build the engine I'm planning to end up with.

If I workout the bends and tack it together I can it welded by a professional for damn near free, so if I can get a flange for less than a lot of money it seems a viable solution.

Taiden
Taiden Dork
12/1/11 10:29 a.m.

3/8" steel bar
hacksaw
drill
holesaws
metal file

MG_Bryan
MG_Bryan Reader
12/1/11 10:34 a.m.
Taiden wrote: 3/8" steel bar hacksaw drill holesaws metal file

Yeah, that just seems like it would be super sloppy since the exhaust ports are almost square. Guess it doesn't hurt to have a go at it though

92CelicaHalfTrac
92CelicaHalfTrac SuperDork
12/1/11 10:35 a.m.

JGS tools doesn't have flanges?

mad_machine
mad_machine SuperDork
12/1/11 10:39 a.m.

it would probably be worth your time to find somebody with the proper tools.

DILYSI Dave
DILYSI Dave SuperDork
12/1/11 10:39 a.m.

Garage = use the tools you have. Nothing magic to it. I like 3/8" thick for a turbo flange.

Easy button if you can = use the gasket to create cad, and have it laser / water jet cut.

MG Bryan
MG Bryan SuperDork
12/1/11 10:41 a.m.
92CelicaHalfTrac wrote: JGS tools doesn't have flanges?

Seemingly, old men in tweed coats don't like turbos on their MGs, so I don't think I have any hope of finding an off the shelf solution.

92CelicaHalfTrac
92CelicaHalfTrac SuperDork
12/1/11 10:42 a.m.

Let me check for ya.

Otherwise... maybe just cut the flange off a stock manifold?

MG_Bryan
MG_Bryan Reader
12/1/11 10:44 a.m.
DILYSI Dave wrote: Garage = use the tools you have. Nothing magic to it. I like 3/8" thick for a turbo flange. Easy button if you can = use the gasket to create cad, and have it laser / water jet cut.

I've no trouble drawing what I need in cad, I've just never had to pay for a shop to cut anything before and haven't gotten around to making some phone calls and finding out what it would cost.

Has anyone here made and exhaust flange with hand tools? Pictures of the results?

ditchdigger
ditchdigger Dork
12/1/11 10:46 a.m.

3/8" thick cold rolled steel and some creative layout with drill bits and hole saws should get you square ports with minimal grinding to finish them up. Lay a gasket on the steel, use a sharpie to transfer the shapes and get to work. It ain't rocket surgery

I fully endorse boosting old motors. You would be suprised how much they can take.

My manifold for the Fiat 850. It holds 20psi!

mad_machine
mad_machine SuperDork
12/1/11 10:48 a.m.
ditchdigger wrote: I fully endorse boosting old motors. You would be suprised how much they can take.

Not at all.. those engines were built before the days of computers.. so everything is usually a bit overbuilt for it's purpose

ditchdigger
ditchdigger Dork
12/1/11 10:53 a.m.

I just remembered what an MGB manifold looks like. It will be three small pieces. Looks pretty easy to do at home. Even a jigsaw with a fine toothed blade would get it done....it would take a while but it would do it.

The mounting to the head/intake manifold points will be more critical than the exhaust ports.

wlkelley3
wlkelley3 Dork
12/1/11 11:08 a.m.

An ebay MG header to cut and modify for a turbo. Believe there are turbo headers available but not easily found. MG's seem to be supercharged more than turbo. They handle supercharging well enough so they should handle turbo-boosting just as well.

Taiden
Taiden Dork
12/1/11 1:01 p.m.

A properly sized drill bit in the four corners of each 'square' should produce fantastic results. Match the radius of the corner to the radius of the drill bit you use. Then use a hole saw to 'hog out' the area adjacent to the drilled holes and use a hack saw to connect them.

Or just pay to get them water jet cut, milled, conjured out of thin air, whatever.

Curmudgeon
Curmudgeon SuperDork
12/1/11 7:47 p.m.

Why do all that? Get a one piece manifold used on the 76-80 engine, cut away the intake part and voila: a nearly finished turbo manifold. Fo' cheep. Carb side:

Engine side:

MG_Bryan
MG_Bryan Reader
12/1/11 7:53 p.m.

In reply to Curmudgeon:

While I'm pretty sure I could get one for free, I've actually never owned an example of that manifold, and don't see any on Craigslist. I suppose I could just cut the flange off of the pacesetter that's sitting under my workbench, but I'm probably going to give the hand drill and files method a go this weekend just to see if it works out for me. If it does, I have more than just an MG to turbo.

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