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MG MGB GT V8 Factory Originals Technical - V8 Cooling

Morning all,

Whilst chatting to a friend of a friend recently about MGB V8 cooling fan issues, I was told that there is a fan conversion using a pair of Citroen BX fans rather than the original pair of yellow four blade fans with exposed motors.

It appears that the BX fans are slim enough to fit in front of the V8 radiator and are shrouded. I was interested to see what solutions other V8 owners have come up with. Any thoughts on what diameter fan is best? Is a pair better than a single? Has anyone made a shroud to direct the cooling air? Is an MGB Kenlowe better than the twin fans? Is it big enough?

I don't think I'm having any cooling problems at the moment but the original fans just look REALLY inefficient and it's bugging me! There must be a better way.

Any comments gratefully received

Andy
Andy Kenning

Andy,
Totally agree with the comment concerning the original fans.
Two fans , no shroud and a mesh guard. That would have to be about as close to how not to do it as you are likely to find.

Anything which improves the airflow over the original spec set up must be an improvement worth persuing.

Cheers , Pete.
Peter Thomas

I've tried three different electric fan solutions. First was a large dia. puller with a partial shroud out of a small chevy of some type which sort of worked OK, then a much better large fan, then added a Mercedes shrouded pusher in front. I now use a 17" dia fully shrouded crank driven 6 blade steel fan but have come to the conclusion that it all depends on your configuration. If you have extended the radiator core then you very likely have room enough for a single large diameter fan. The sweetest setup I've seen yet is the "sidewinder" fan available from Mantell Motorsports. It'll be a little pricey, but by moving the motor to the corner of the radiator and driving the fan with a small cog belt they make it really compact. It definitely has that "Wow" factor. You'll have to contact Pete for more details but in my opinion that is probably the best you can get. As for multiple fans, so far I've not seen any multi setup that can come close to the same airflow for a given area, but that only means that for a roughly square radiator a single fan is best. Where multi's work well is for a long narrow radiator.

Jim
Jim Blackwood

Andy, yes the original yellow fans are pretty inefficient because a lot of the air they move flies off the ends of the blade tips instead of being pushed forwards. That's why shrouded fans are better. Another thing that's well worth doing is trying to seal all holes and gaps from the engine bay to the area in front of the radiator. If there are gaps, then when the car is stationary and the fan comes on, hot air escapes round the radiator and you end up pushing some of it back through the rad. Not what you want. The problem the V8 B has is that there isn't much facility for getting rid of hot air. It basically has to go downwards and out the bottom. That's why quite a few conversions have louvres in the bonnet lid.
Mike Howlett


Following up on Jim's note, here's a photo of the "sidewinder" fan:
http://www.britishv8.org/Articles/Images-V14-2/PeteMantell-Tech-A.jpg

Here it is installed on Robert Milner's MGB-V8:
http://www.britishv8.org/MG/RobertMilner/RobertMilner-D.jpg

Here's the contact info for Mantell Motorsport: http://www.britishv8.org/Sponsors/Mantell-Motorsport.htm

There are LOTS of other good options for fans... you can find hundreds more photos of them (installed on MGB-V8s) from here: http://www.britishv8.org/Photos-MG-Conversions.htm
Curtis Jacobson


Here's a pretty good report that compares performance of a couple fans: http://www.teae.org/cooling/cooling_article.html

I found one comment in the article particularly interesting: an electric fan's motor obstructs airflow, so it should preferably not be placed up against the radiator core.

---

"Has anyone made a shroud to direct the cooling air?" Several people have. Dale Spooner's is a nice example: http://www.britishv8.org/MG/DaleSpooner/daleenginebay2.jpg

Another alternative is to just have a "fan ring". The advantage of a fan ring is that it enhances the fan blade's efficiency without being an obstruction to natural airflow when the car is at speed. (When the car is moving the electric fans aren't productive anyway, and based on a test I did they actually become measurably counterproductive at highway speed.)
Curtis Jacobson


Mike said: "That's why quite a few conversions have louvres in the bonnet lid."

Or in the inner wings! http://www.britishv8.org/MG/BruceMills/BruceMills-C.jpg
http://www.britishv8.org/MG/PaulSchils/PaulSchils-D.JPG

RV8 style headers help cooling quite a lot by venting air into the wheel wells. The front wheel wells on a moving MGB will be at a lower pressure than the engine compartment. On my GT, I measured the difference to be about 0.40 inches of water at sixty mph and 0.65 at seventy, which IMHO is pretty significant.
Curtis Jacobson

The article on the fans is excellent. I had been thinking that I needed more holes in the radiator support for air to get in the front. Just opposite of what is needed. And the fact that the thin blade turbine fans aren't the best was also an eye opener. The graphs that the article has follow exactly what I see in mine.

I know that I have an excellent radiator. But if I get stuck in traffic, temp does go up. I am going to look in the Summit cat. for a different fan.
Richard Morris

After trying different vents ahead and beneath the radiator, i realised that the fans fitted with a scoope worked much better than the BL BGTV8 setup. I finally ended with a twin van installation behind the radiator and a inlet scoope under the bonnet pannel and one behind the front vallance, directing the air directly into the mash of the radiator.
The twin fans are not that effective but there was not room enough for the large scooped single verion i tried, as it sometimes fooled the whater pump neck.
The large single ventilator would have been the better choice as it was capable for more air succed through the radiator at a lower electrical current, but i would have had to redesign the compleate installstion of the radiator to make it work durable on my car. So i only have the second best solution selected for the 3.5 SDI engine.

I set the electric switch to @ 85 deg. C. and, even in stop and go, there is no reading higher than 90 deg C. on the (tested) instrument.

Before fitting the scoopes in front of the radiator the water temperature rose to 100 deg C.(boiling) with the twin setup behind the radiator while the large single one was able to keep the reading at @ 95 deg. C. in this installation without scoops.
The radiator on my car is a std. MGBGT V8 as is the waterpump.

With the vents ahead of the radiator and without shrouds it might work with the 137 BHP V8, but if there are any upgraders done to the engine cooling becomes a problem with the OEM setup.

Ralph

Ralph
Ralph

Thanks for all the input guys. Just off to read the Tiger article. I'll add a posting to let you know how I get on.

Andy
Andy Kenning

I looked for the Sidewinder electric fan (Mantel and eBay). Don't see it anywhere.

Something called fanman showed one (over 400 bucks) but not available.

Anyone have a working link to one?
Richard Morris

Vents into the wheel arches (low pressure zone) as per the RV8. and or
Put two smaller close coupled electric fans. One on the top front left hand side and also one on the rear bottom right hand side.
Peter

Ralp, could you post some pics (link) of what you did to fabricate/install the inlet scoops?
Mike Maloney

It gets hot in SoCal I used the twin fans off the donor Range Rover to cool my "B". They are fully shrouded so that all air entering the car is directed to the radiator.



M Mallaby

Richard I can give you Pete's email address:

pjmantell@prairieinet.net

Jim
Jim Blackwood

This thread was discussed between 13/06/2007 and 15/06/2007

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