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MG MGB Technical - MGB Dizzy and Carb Swap - worthwhile??

Hi There -

I'm about to gather the parts together for some fairly comprehensive work on my 1981 MGB GT LE, and would be grateful for a few candid opinions.

The car has a VERY high (180k) mileage, and from the full history I know that the dizzy and carbs have never been replaced (though the engine's a recon). The car has got so lethargic and thirsty now that it's almost undrivable, so now's the time....18mpg on my last motorway run!

My question is this: I really want to swap the HIF carbs for the earlier type, as I feel a LOT more comfortable tuning and maintaining them: is it also worth renewing ther distributor, considering the mileage of the car? If so, should I swap it for a pre-rubber bumper one? I'm less concerned with ultimate fuel economy than with a bit of extra performance -I'd love to start out-dragging milk floats.....

In time, I'll want to uprate the exhaust (extractor manifold) and do other mild tuning, but I'd like to get the basic car right first.

Any advice much appreciated!
Thanks
Bruce
Bruce

Bruce,

What is wrong with the HIF's? I have them on my '73 tourer (now +/- 260.000 km's on the clock) and think they are easier to adjust than a HS4 and less prone to leaking etc. The only downside is that the metering-needle is sprung, so it will always wear, become thinner and enrich the mixture in the proces, but on the plus-side you don't have to center the needle.
Get a full repairkit for the carburettors from Burlen or someone else and you won't believe the difference: I didn't! I have K&N's in the original canisters and now run the standard AAU needles in stead of the recommended AAA ones because of the wallet-busting mpg, it really ran to rich. I'm now planning to get the slightly leaner (compared to AAA) nr.6(?) needles, modified for HIF use (a collar is pressed on I think).
The distributor is also important, why don't you have it checked on it's characteristics (spelling?) by an expert. I never changed the springs in the distributor but always kept it clean and well oiled so there's still no play (it has been in the family for about 25 years) in it.
Willem van der Veer

Bruce. I would agree with Willem. The carbs need to be removed, cleaned and inspected to see whether they may be rebuilt. You can, always, swap them out for a new set of HS-4s or HIF-4s, if that is what you prefer.

As to the dizzy, it too needs to be removed and inspected by someone who is competent to test it for functioning and condition. Based on that inspection, you can decide whether to have it rebuilt or replaced. Aldon Engineering, at one time, offered such services.

Without a comprehensive series of tests to evaluate exactly how your engine is performing and what may be the root cause of any performance limitations, simply replacing parts in hopes of seeing an improvement, is not the best way to go about things. Les
Les Bengtson

Bruce 180k high mileage? it would be just runin in Aus.
DENIS

Hi,
Question here. I own a 1980 MGB Mark IV and was told that was the last year they were built. Were they built after 1980 and just discontinued being shipped to Canada?

Cec


Cec

They stopped building Bs in 1980 but some were not registered until 1981.
Chris at Octarine Services

This thread was discussed between 15/05/2004 and 18/05/2004

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