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MG MGB GT V8 Factory Originals Technical - Edelbrock Performer manifold?

Will the Edelbrock Performer manifold (plus 500cfm carburettor & air cleaner) fit under a MGB bonnet without modification? I have a Roadster V8 conversion with a standard SD1 engine. Currently it has the standard rover manifold but it has been machined down and a custom 'adapter' fitted so the SU's sit in a similar position to the GTV8's.


A Butterworth

I have built my own filter system with KN. I have also handcrafted a bulge to the bonnet for some clearence between all. I have 3.5 SD1 engine, 500cfm is too big for them, 390cfm is already too big. I have Holley 390cfm with Hoffenhauser manifold.

Hi Andy
Don't suppose you got your car from a dealer in Blackpool this summer? I was looking at a car with that set up but by the time I got my act together the car had gone!
Nick Bentley


I've got the exact set-up you have. I couldn't get it to fit under the hood (even with a scoop added) until I found a 14" drop-base filter assembly. It drops the filter about 1 1/2" and I'm using a two-inch paper filter for now. I'd like to get K&N in there but their smallest filter is 2 1/4".

I also had to remove a bit of the hood cross-brace to clear the filter.

Contact me off-site if you like and I can send some pictures. The drop-base assembly came from the States and worked out to about $65 CDN, but it does work.

I can also tell you what size metering jets and rods will work better in the carb than what it comes with.

Simon Austin

Hi Simon

I would be interested in information on "what size metering jets and rods will work better in the carb"
I have always though my set up (the same as yours) should have more umph

Bruce Mills

Hi Bruce:
As you know, my car isn't drivable yet but I have an Edelbrock 500 cfm (#1404) and Performer manifold for my 3.5 Rover. I called Dan Legrou from D & D and explained the work done to my engine and asked for re-jetting recommendations. He sent me #1421 meter jets and #1441 meter rods. My engine has a fairly agressive cam, some head work, port matching, 3-angle valve job, ceramic coated pistons (10.0:1) and combustion chambers, ceramic coated block huggers, balanced pistons/rods and lightened flywheel. Dan has a lot of experience with this engine - I expect that the combination will work for me.

I'll send a couple of new pics soon. I have the rebuild front suspension (powder coated/poly bushings) and the hubs/rotors and steering rack back in.
Phil O


You don't say whether your car is chrome or Rubber bumper. I believe there is a little more room under the bonnet/hood of a rubber bumper car, I have an early rubber bumper car with Edelbrock Performer and Weber/Edelbrock carb and it would not clear the bonnet
with a large diameter air cleaner you can fit a 14"x2"
low rider under a RV8 bonnet or you could possibly look at the new K&N plenum chambers that allow you to use one or two cone filters which can be positioned towards the rear where there is more space.A question I must ask is,why change the SU'S which are if the adaptor on the manifold is of good quality (and not the ones that turn at a right angle) good enough to flow sufficient mixture for 200BHP+. IMHO If you are going to spend that sort of money for the manifold carb and filter approx 600.00 you would get a better return for your money by buying a pair of Peter Burgess Econotune Heads which I believe are worth about 30-35BHP on a good condition well set up engine.
You could also change the cam while the heads are off if you wanted a bit more grunt, but its a case of where do you stop.

Phil O I have a similar engine spec as you and I was recommended to have the same Jets and metering rods as you have so it should be fine you may to fine tune the transition from 2 - 4 barrels mine has not yet been fine tuned and when you strayinto the second two the power comes in with a bang easily spins the tyres in second gear! Unfortunately not going at all at the moment see No spark.
Good luck hope it all goes well.

K.R Jackson

Dear KR,

I wasn't aware that alternative 'right angle' manifolds, for fitment between carb and main manifold, were available. Do you know who sells them?

Regards, James


The adaptor I was describing was in my opinion not very efficient if you can picture two tubes cut and welded at right angles. I believe that Clive Wheatley may have reproductions of the original BV8 adaptors give him a call and see what he's got.

Kevin Jackson
K.R Jackson

This thread was discussed between 12/12/2004 and 23/12/2004

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