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MG MGB Technical - Headers

Would adding an aftermarket header to a stock B improve the vehicle's performance or would it just be a waste of time and money? I know they help with modern cars. I am currently running a stock manifold and a terrible reproduction downpipe. The bends are in 3 stages rather than just one single bend. I appreciate your time and consideration.
--Robert
Robert

Robert, I have read on this site forever that the stock header is tuned better than any that you could buy.
Steve C.
Steve C.

The stock manifold with a falcon Big bore system is hard to beat and lasts and lasts. Bob Thompson/International Auto
Bob Thompson

I have to agree with Bob Thompson. The Original Equipment exhaust manifold hasn't been improved upon for street use on anything other than a Big Bore engine. Although I'm a Peco fan, I also agree that the Falcon single box system is an excellent choice.
Steve S.

Stock manifold is great...UNLESS...it is from a North American spec rubber bumpered car.

rick
rick ingram

Thank you all for you input. I have a feeling that the engine is producing about as much power as it will without spending money on internal parts. It has a custom intake manifold(that did help), K&N filter set, no smog equip, and the exhaust is a stock manifold running through a straight pipe with a glass pack at the very end. Vehicle is a 69 Roadster. Actualy, I probably need to spend my money to fix my lose spokes and the squeaky wheel. Then do some cancer repair. But I appreciate all of your help in this matter. It appears that my money is better spent else where.
--Robert
Robert

All headers leak; all headers are noisy; all headers are a terror to fit; all headers eventually burn out. All headers are headaches! The factory exhaust manifold, couple with a twin exhaust pipe, is by far the "best" combination for a street car. Can you improve the BHP of the engine by changing the exhaust? Sure! But only marginally! There are many, many things you can do, from free to thousands of dollars before you happen upon the exhaust as a method to boost BHP.

John Twist
University Motors Ltd
John H Twist

Headers generally only help at high rpms like a race car would need. Most headers aren't designed well and can actually decrease your performance. There's a science to header design and while you can buy all kinds of tuned headers for American engines there doesn't seem to be kind of offering for MGBs or almost any foreign car for that matter. One size does not fit all. I would buy a new lower restriction exhaust instead. If you really want to spend some money send your stock manifold to Extrudehone.
Mike MaGee

There is a tubular manifold and downpipe that has been held for many years to improve gas flow, joins the front and back ports about half-way down then the middle port joins just after the rearward bend. MGOC still sell these as a 'performance' manifold for both RHD and LHD.
Paul Hunt

i have a maniflow header installed. it was jet coated - ceramic coating - on the inside and outside. it wasn't a problem to install.
RN Lipow

Robert, is it possible your bolting on performance items on a old tired engine?
J Moore

Eh, well um- I hate to refer to it as being old and tired, but yes, at nearly 140k miles on the origional drive train I guess it is. It still runs strong and burns little oil. Most of my money is currently going into putting a LT1(aluminum head 350) Chevy into a GT that was rescued from a salvage yard. I am getting a little tired of the lack of go once the car is into third and was hoping to pick up a little more umph for not to much money. I actualy have a equal length header that used to be on the car but it did very little as far I could tell.
-I am doing a lot of highway driving in it right now- what would be great would be a set of 3.40 gears and about 50 lbs more torque to turn them.
Thanks for everybodies time and help.
--Robert
Robert

I was doing the same thing with my 100K engine, I finally decided I need to take a look at the bottom end and it was WORN OUT! Most of the bearings were down to copper and the bores had good ridges. Now I'm glad I caught it before I did real damage! It's only parially expensive as opposed to REAL expensive! :)
J Moore

The Peco system is just fine...well engineered, fits well and installs without problems. Sounds good also....only reservation is the stupid useless "paint" they persist in using!
Pete
77B
P J KELLY

This thread was discussed between 20/11/2003 and 21/11/2003

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