MGB MGB exhaust system

[GaryBeu]

Well ya'll our center muffler is coming loose so we thought "we better order a muffler". While the car was on the rack getting a tire repaied at the tire/muffler shop we discovered that the header has a 3" long crack and the pipes have small holes everywhere. The shop said that if we get the parts they'll put it on for $50...sounded good.

We've now discovered that we apparently have a "performance" header with three pipes off the engine. Looking in Moss and VB this is twice the price. Question now is this...is it easy to just convert it back to the 2 pipe header or do we need to stay with what we have? We're in totally new territory here so any suggestions will be greatly appreciated. Thanks.

Gary and Carla

 

[Mickey Richaud]

Lots of opinions here. And the current issue of <span style="font-style: italic"> Classic Motorsports </span> has a write-up on the pros and cons of different systems.

The factory cast iron manifold is a good choice, and good used ones pop up on ebay all the time. However, you're probably needing this now, so maybe someone here has one you can grab, if you choose this route. Since they share fixing studs with the intake manifold, you'll need to be sure the flange thicknesses match. Otherwise, it's pretty straighforward.

Mickey

 

[davester]

My preference would be to convert back to original, since it'll be sturdier, get rid of some of that excess heat in the engine compartment, and the performance of an aftermarket header isn't much better than the stock. You'll need both the cast iron manifold and the 2-into-1 exhaust pipe forward section, plus the donuts and new brass nuts to join them. Ask around here or the other forum to see who's got a manifold they can sell or give you.

 

[PAUL161]

My preference would be to convert back to original, since it'll be sturdier, get rid of some of that excess heat in the engine compartment, and the performance of an aftermarket header isn't much better than the stock. You'll need both the cast iron manifold and the 2-into-1 exhaust pipe forward section, plus the donuts and new brass nuts to join them. Ask around here or the other forum to see who's got a manifold they can sell or give you.

It's a proven fact that aside from being a little heavier,(not needed in racing), for the street, the stock exhaust system is about as good as it gets. I removed a header set up on the wifes B when I restored it and there is no difference in performance that I can see. PJ

 

[DrEntropy]

Yeah, path of least resistance is to fit a stock header/downpipe system. If Hooker were still in business, THAT is the only pipe header that fits worth a durn, IMO.

... I wish I'd saved one of 'em from back-when. :frown:

 

[CZ_Dave]

Might just have one layin around here some place, If'n I got more than 1, I'll give her up at a fare price, you pay shipping. For a 71, right? Easy to put on just remember how ya take off the Carbs and intake manifold, then just have your local shop add a section on the exhaust. Fare enough?

 

[GaryBeu]

Dave...sounds more than fair to me. Please let me know what you find. Thanks.

 

[CZ_Dave]

Okey Dokey Dawgie Daddy, I will look around in the next day or too and get back to choo.

 

[GaryBeu]

Thanks again...and yes, it is a 1971.

 

[CZ_Dave]

Ok Gary, I have 3 stock exhaust manifolds that will fit your 71, your welcome to one of them, give me a call on my cell if you want it so we can iron out the details. They are used and in good shape. Fare enough? 818-636-3796

 

[BlueMax]

Gary, I had no issues installing Moss’s stainless steel header in a 71 MGB I did last year. The flanges were the proper thickness not having to shim to apply equal pressure between the intake and the exhaust. I sure love the ringing sound they make each time the cylinder fired.

 

[GaryBeu]

Thanks Dave. I'll call you tonight.