Welcome to our resource for MG Car Information.



MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - Californian '79 MGB .... now here in Belgium

Californian '79 MGB .... now here in Belgium

Hi guys, I'm helping out a friend who has a 79 MGB, its a California car and totally rush free which is, well a miracle.....

The car is fitted with a single zenith-Stromberg, if I ditch the air system and cat, replacing it with a K&N filter and cat replacement pipe, will it run well enough on the standard carb needle, is there anything I should be aware of when doing this ? its an interim solution to enjoy the car over the spring / summer.

What is the ideal single carb conversion ? something like a DVG32/36 or single HS6 for example. Would the DVG bolt onto the original inlet manifold. A decent exhaust is high up on the shopping list......any ideas welcome.

Kind regards

Matthew Mason

A California car in Belgium. I have a California car on the east coast of the USA. Those California MGBs sure get around. As far as the carb conversion, I think if you are getting rid of the ZS then a Weber DGV 32/36 would perform better than the single SU, HOWEVER, I have seen those who switched from the single ZS to the twin SU set up with good results. I believe either way you go will require a new intake manifold and other mods. I can't comment on the carb needles as I am still trying to figure that out myself. The PECO exhaust and header is mentioned in Peter Burgess book on power tuning an MGB but some threads here have said the quality of those units has dropped. Again I can't speak from experience.

I have a HIF44 with a Austin Marina manifold on my '79 B
It improves performance and driveability a lot
Pat in Tehachapi
patrick bailey

well at this time of year - you need to protect against the saltiest roads in Europe - with a low compression car you might then consider power - previous advice is good but a shaved head need not be very expensive unless you clean up the breathing at the same time - then go for the twin SUs which are cheap and plenty - your successor will be pleased to see a ' standard fit car'.

FWIW - Roger

I have an ex California car (supposedly) down here in New Zealand. I should get around to getting a Heritage certificate one day to really find out.
Simon Jansen

Matt. Congratulations. A completely rust free car is rare, even here in Arizona and over in California. Your friend is fortunate both to have the car and a friend to help him with it.

The Z-S carb may be useable or it may not be. I have seen some cars which ran quite well on them and others which could not be made to run well with the Z-S. In the long run, I have never seen a Z-S which ran well for many years. I have seen SU and Weber DGV carbs which could be set up, then run for years without further tuning. Hence, you will eventually want to replace the Z-S with a better form of carb. Twin SUs HS-4 or HIF-4 would be my choice. This will require the carbs, the K&N filters which allow the use of such carbs on the RB cars (brake booster/servo gets in the way of the use of most air filters, but K&N makes a cone shaped one which works), a new intake manifold and an exhaust manifold. Stock MGB parts will work fine for these applications.

As to the Peco system, it is a difficult thing to install in the RB cars due to the brake servo unit. I had to unbolt the engine from the motor mounts, lift the engine several inches, swing it to the right side of the car, then, install the Peco header. Either the Cannon header or the original (CB) exhaust system is easier to install.

The original RB cars were equipped with a one piece intake/exhaust manifold which makes it difficult to change out just the carb. It is possible to cut off the intake portion and, with some work, make the exhaust portion work. However, many of the current manifolds have developed a crack on the inside curve where the exhaust manifold mated with the cat converter. I originally had the exhaust portion of the RB intake/exhaust manifold on my 79. Numberous problems lead me to install the PECO header (not recommended) and add an inline cat to the system (required as part of our emissions testing program). Were I to do it again, I would use a factory (Chrome bumper) exhaust manifold and the header pipe linked into the existing exhaust system.

Beyond that, I would not make any modifications until I knew they were needed. My original 79B performed well on the German Autobahn cruising at 85 mph in 4th gear/overdrive. It was to US spec without the cat being installed. If in good condition, your friend's car should be able to do the same. (Drove mine on part of the Belgique Grand Prix course several times while driving from Pruem to Spa--the part that is normal roads.) When you have been able to decide what needs to be done to the engine and suspension, spend your money on that in a focused manner.

Les Bengtson

This thread was discussed on 10/01/2006

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.