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MG MGB GT V8 Factory Originals Technical - Carb choices

Hi all

I have a 3.5l lump with Isky cam and lifters in it.

It came with a Clive Wheatley rear facing inlet manifold and a pair of new HIF44's. However I have available a Holley 390 with Offy inlet manifold.

Now i need to sell one set, and was trying to figure out which set to go for.

I would like to go fo EFI in the end so the carbs may only be short lived.

But who has experience of both sets and which would they recommend?

Matt
Tarquin

Matt,

i would go for the holley and buy a tric kit, change to larger shooters, an other excellerator cam (i think it was the pink one that worked best on my installation with LT 77 box and 3.3 rearend) and use the weaker springs for the secondaries (coded with a black paint mark). Compared to the SU-setup, the result will be very satisfying.
If you sell the SU carbs with th BGT V8 inlet system as a set, it might finance the swob to the EFI, i think.

Ralph
Ralph

Matt ,

Another vote for the 390 from me.
A good choice for the 3.5 and plenty of information and kits in the marketplace if / when you need them.

You may also find the packaging easier with the Holley and the the SU's.

Cheers , Pete.
Peter Thomas

I would prefer the Holley/Offey set up too. But, if I lived in the UK, I'd probably opt for the SUs. I get the impression that Holleys are thin on the ground there, whereas my local speed shop sells everything for Holleys. Plus my nearest tune up workshop knows all about them. So why did I fit an Edelbrock to my GT ? The SU is a lot more DIY friendly also. If you intend to end up with EFI, why not start out that way & save yourself extra work ? Barrie E
Barrie Egerton

Barrie ,
A very valid point about the EFI set up and starting out there instead of trekking the more convoluted route via carbs.

Cheers , Pete.
Peter Thomas

EFI it is very easy, and cheap, to set up.
http://www.britishv8.org/Articles/Rover-Hot-Wire-EFI.htm
I did it slightly differently.
Air intake.
Get a local machine shop to weld up the three vacuum take offs in the trumpet tray and tidy up any left over bumps or lumps.Especially the ones on the bottom. Then machine 16mm off the bottom and 10mm off the top. That should get it under the bonnet. Remember to drill the locating dowel holes deeper and measure the height difference between the two levels of trumps; before machining.
You can take another mm of both top and bottom and even 7 off the top cover, but it shouldn't be necessary.
That cost me $100 to have done.

Fuel supply.
Cheapest, quickest, easiest, quietest approach is to use a twin pump set up. The ususal high pressure bosh pump is fed by a
"universal autosuction rollervane pump made by Peirburg.

http://www.pgnews.msi-motor-service.com/download/pg_gesamtkatalog/data/pg_aa02_krvg_web.pdf

As far as I can tell it’s Pg 75. Part # KP 7.21440.53.0 or KP 7.21440.51.0 there doesn’t seem to be any difference. The guys I got mine off called it part #12001.

Use a later style MGB fuel sender that has it's own fuel uptake line incorporated in it.
A big filter just prior to the feeder pump acts as a swirl pot.

So you see, dead easy, off the shelf bits.
There is even someone selling a custom made tank now, which would be even better.
http://www.mgexperience.net/phorum/read.php?40,747959


Peter

EFI does seem to be the way to go if you're planning one out.
If you can find a Carter 400cfm, it's very well suited for the job. Pair it with a Buick manifold and it fits under the bonnet with room to spare. Both can be sourced here in the US on a regular basis.

Kelly
Kelly Combes

Why not hog out the manifold you have and use a pair of 2" SUs instead? Should work as well or better than the American carbs.
Bill Spohn

This thread was discussed between 02/04/2008 and 10/05/2008

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