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 - Has anyone put a viscous fan on the B-series engine

While replacing the electric fan on the family Renault Espace, I got to pondering about putting an electric fan on my 1964 B. The electrical system still has the dynamo which works fine but is set up for the minimal requirements of the early car and could cause problems when it gets really hot here in Berlin.

A viscous fan would seem to provide a good alternative. Has anyone fitted one to their car?

Mike
Mike

I read that as vicious! I was wondering if you'd found a fan with teeth and axes attached or something...

Viscous fans sound like something else to fail... if you're having cooling problems, could it be that there's something else amiss in your cooling system?

ttfn,
--
Olly S
Oliver Stephenson

Mike,
I assume you are thinking of replacing the stock fan. I would be more worried about the water pump shaft/bearing loading with the viscous fan. Most viscous fans are pretty heavy. Your electrical system should keep up with a modern electric fan with thermostatic switch. Shouldn't pull more the your heater fan and when you're running one the other one shouldn't get as much use.
Leland Bradley

Mike-
If you're worried about overheating this summer, I'd suggest that you:

1) Install a 160 degree thermostat.

2) Thoroughly descale and flush your engine and radiator. You'll be amazed/aghast at what comes out!

3) Mount the later plastic fan. It's more efficient and moves more air through the radiator rather than stirring it around inside the engine compartment.

This should be enough to handle the cooling of a stock engine. If you've made modifications to enhance the power output of the engine, then I'd suggest:

4) Recoring the radiator with a four-row aluminum core that has 15 fins per inch. If you've got a really hot engine,

5) A radiator shroud will be a worthwhile addition.
Steve S.

Please forgive my ignorance, but what is a viscous fan?
Paul Noble

the fan is coupled to the engine by means of a viscous - or fluid coupling. I believe that at speeds exceeding 40mph the fan freewheels and does not create a drage on the engine.

rn
RN Lipow

I see. It sounds a little like the "clutch" fans that some American V8's had in the seventies. I think that they were more temperature sensitive, but the idea was the same; disengage the clutch when normal airflow through the radiator was sufficient.
Paul Noble

I heard that Triumph had a fan that would free wheel and that it could be adapted to an MG. Anybody ever heard of that?
Devin

Devin & others-

The BL 1500 motors had this type of fan fitted. At least I saw a 78 midget in a local shop with one. It appeared to be stock.
Jared Snider

Consider a lighter, cheaper alternative: a Flex-a-lite fan, as used by hot rodders. They are very light, cheap ($28) and will never go bad, unlike the viscous coupling. The fan blades are made of curved stainless and reduce drag by flattening out at higher speeds. I used one in place of the stock, very expensive viscous coupled fan on a Range Rover. Worked great. They are available in speed shops or from Summit Racing or Jegs.
Cheers, Andy
Andrew Blackley

Many thanks for your tips, Gentlemen.

I had slight overheating problems in heavy traffic and Berlin's summer heat, but I descaled the radiator and heater this winter. If it's done as much good to the radiator as it has to the heater (real heat now!), overheating will be a thing of the past. I do reccommend rinsing out with concentrated acetic acid (vinegar). Steve's right, it gets loads of muck out.

No, my real concern was the power that that fan wastes...

Mike
Mike

This thread was discussed between 31/05/2002 and 03/06/2002

MG MGB Technical index

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