MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

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 - Just a Few Questions

Alright, I've got two questions. Number one, I don't think my alternator is working. I bought the car from someone who kept all of his repair/restoration (I bought the car when the 'restoration' was about %40 done) and there is a receipt for an alternator rebuild at my local MG mechanic/parts place. I checked the battery with my charger's gauge and it says that it isn't being charged while the car's running. The alternator was working, but now not. I read one post where it said if you disconnect the battery while running it fries the alternator. Now, I didn't disconnect the battery, but, the cable did pop off a while ago when I was taking my first...hmm...test drive in it, could this cause it?
Now question number two. I'm a stron believer that it is better to get cold air to the carburaeter instead of that hot air in the engine bay. Other than a hoodscoop, is there a way to duct cold air to it? I tried to come up with a way to use one of the slots in the front of the bumper as a built in air scoop, but I just can't figure out a way to do it....any ideas?
K McCaffrey

You didn't say what year "B"...but mine is a 79 and has an alternator light in the center of the dash...it glows if the alternator is not working...sometimes it "glows" a little at idle.

Not sure about the "cold" air into carb. I am sure the "brits" had a very logical (??) reason for designing the air flow into the carb they way they did..

Ron
79B
Ron Eberhart

Hi.

Alternator :
Yes, you may well have killed the alternator.
I suggest you take a look at the current thread 'dead battery' or something like that.

Cold air : I used a piece of trunking to take cold air from a (purpose cut) hole in the panel at the side of the radiator to the front air filter box, which I had previously cut the 'elbow' off.
I partially blocked the rear air filter box intake, so nearly all of the carb's air comes from the front, with the aid (I guess) of a little ram effect when driving. I have had no problems with this arrangement, but it doesn't seem to have provided any significant improvement either.

My guess for the reason for the standard air intake arrangement is this :

The car needed to be drivable after a cold start in temperatures as low as -20c, and the elbow type air intake (later models) provided air that had been warmed by the exhaust manifold. Many cars of the era had some method of 'switching' to unheated air, either manually (turn the air filter housing round) or by means of a thermostatic valve.. so far as I am aware, the B never got this 'refinement'.

HTH... Don
Don

Alright, my B is a 77, and it was converted to a Weber carb w/manual choke. And as for using the two slots in those beautiful rubber bumpers, wouldn't I end up blocking the airflow to the radiator, making my cooling fan work much harder? Any ideas?
K McCaffrey

This thread was discussed between 27/09/2003 and 28/09/2003

MG MGB Technical index

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