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MG MGB GT V8 Factory Originals Technical - OEM Cooling Fans

Anyone have specs as to CFM that stock fans generate?

Thanks in advance
Steve LaGoy

I've never seen these figures published and it wouldn't surprise me if the manufacturers of those fans were so uninterested in what they were producing and also they had a large bulk - and undemanding -(Leyland) market that they never even bothered to find out.
I suspect that the answer to your question is somewhere in the region of not-a-lot.
You also need to be concerned with the current draw required to produce not-a-lot which I suspect is in the region of quite-a-lot.
Sorry
Marc

Marc,

Was that a metric or imperial 'quite a lot'?

Frank
frank swinton

Frank
Good question.
I think that the unit of measurement may be an ancient Sumerian unit using base-60 - I have a feeling that this civilisation was one of the first ever to have discovered the use of 0 (zero) which apart from its various other uses is porbably a fairly handy number for describing the CFM output of OEM fans. They would have been particularly interested in discoveriing this value as they inhabited much of the region now known as the Middle East. I am sure that it will come of no surprise that in such hot climates they had great need of cooling devices and so they invented the OEM fan company and of course OEM stands for Oriental Equipment Manufacturing. This company which in its day was larger and more powerful than the British East India Company nearly three thousand years later. Eventually the OEM Co. Inc was broken up by asset strippers. The more useless parts were sold to British Leyland who nobly ran it as a monument and maintained its traditions until their own final downfall in the late 20th century. There is more ...I'll get back to you about it.
Marc

I am interested in the industrial history of the OSM Co. having had many fine products of the BL/AR/RG/MGRG over the years. I think the problem for the design team of the fans was to provide the minimum restriction to airflow while fulfilling the position on the front of the engine usually ocupied by the cooling fan......... OEM co must also be the manufacturer of the heater fans for MGB and Mini :-)

Phil

Phil

My research so far indicates strongly that during the late Victorian times until post 2nd World War the OEM Co Inc. very successfully produced a range of wooden and then plastic toy windmills - essentially a fan on a stick and I believe that I may have noticed one attached to one of the pillars of my pram. It seems that as the requirements of post-war children became more sophisticated, such fans were seen as uncool(sic). OEM Co. Inc., demonstrating great flexibility and economy decided to retain the tooling and apply it to the production of inernal combustion engine cooling devices.
I agree with you that one of Leyaland's primary objectives was that the fan should meet a mminimum drag target specification in order to ensure that road performance was not unduly impaired by any object occupying - as you correctly imply - that critical position in front of the engine.
Marc

Steve,

What an interesting question, not nearly as interesting as the answers you’ve gotten so far. I’m sure you’d like an answer such as 1200 CFM, but you are not likely to get one because nobody has measured it. Aftermarket manufactures measure theirs as a selling point to the consumer, but OEM have no such need.

I have no idea how aftermarket manufactures measure the CFM of their products, but I came up with an idea to measure the fan output when frustrated with my OEM fans. Knowing that an electric motor and a generator are the essentially the same you can place a small fan in the air flow of the OEM fan and measure the electrical output with a volt/ohm meter. I tried this with an old PC fan, but it was too worn to turn.

This figure would give you something to compare to other fans, but wouldn’t give you the CFM without a lot more work. You would need to graph two or more fans with a known CFM to see where the OEM fit on the scale. This still wouldn’t be very accurate because you would only be comparing wind speed, not volume. To get you would need to calculate the area of the fans (times two for the OEM fans).

All in all, that’s just too much work, but this might help. I replaced my two OEM fans with an aftermarket fan rated as 1200 CFM and it helped, so I would guess the OEM fans are less than 600 CFM each. More important is the CFM through the radiator. Without a radiator the OEM fans push a good flow of air, the aftermarket even better, but through the radiator the aftermarket fan is reduced considerably and the OEM fans are near zero! The OEM fans blow much more air outward than through the radiator, whereas I can’t feel a wisp of air blown to the sides of the shrouded aftermarket fan.
George Champion

We all know that the OEM fans blow "quite a lot" of air out the sides, whereas shrouded units do not. There have been several attempts to make shrouds around the OEM fans with bent sheetmetal, usually looking a bit like the Greek letter Omega.

Here's another idea for someone adept at plastic and metal forming. What about duplicating the OEM fan, but one with an annular ring attached to the ends of the blades? I'm not an aeronautical engineer, but wouldn't that increase the efficiency of the unit?

Just a thought
Paul Kile
Paul Kile

I made the Omega shrouds from aluminum strap and it helped a lot, but not as much as the aftermarket fan which has a shroud in the mount and another connecting the blade tips. The biggest problem with Omega shrouds is one fan’s blades extend past the side of the radiator and more air blows through that gap than through the fins!

After the upgraded heater squirrel cage fan I had hopes that someone would produce upgraded cooling fan blades. Unfortunately, the heater fans went out of production instead.
George Champion

I think what we have here is an example of British humor and why we on the other side never seem to be able to match it.
Interesting to see the split between the Brit input on this thread and us.
A lot of interesting replies here but frankly this kind of question has been thoroughly dealt with in the archive and I think the jocular but very pertiment comments on the poor attitude of Leyland are actually quite true. I do think that George's approach in the last paragraph of his first post where he remarks on the comparable effect of a new fan over the OEM fans is a very useful way of going about the problem. But let's not be humorless
Matt

Wow, I can’t believe I’ve been admonished for providing a technical answer to a technical question. Perhaps the first response to all questions should be “Check the Archives, we’ve got no time for you, but stay tuned for a little song and dance!”

As valuable of a resource as the Archive may be, it does have erroneous answers that can be misleading. In little more time than it takes to direct somebody to the Archives a new summary answer can be posted and it may provoke new questions and answers that could be based on new information. Plus, it seems to take at least an hour to find even a simple answer in the Archive.

Actually, I appreciate the humor on this board, it’s part of the Marque of Friendship that MG is all about, but so is helping our fellow owners solve their problems. I DID say the answers previous to mine were “interesting”. That must not have been a clear enough compliment, maybe I should end all my posts with a humorous tag line like David "How Does He Come Up With These Things" Lieb.

George “This Will Never Work For Me” Champion
George Champion

Ok, Ok, point taken..............

Spending some time over "your side" of the water I know the English humour sometimes passes you by. But I am also interested in upgrading my cooling fans too. Keep the good stuff comming and I will try to "play ball"........

Phil.
Phil Hill

This thread was discussed between 30/09/2001 and 07/10/2001

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