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MG MGA - Electric fan option

I would like fit an electric cooling fan fairly urgently. A couple of questions.

First is the Revotec package for MGAs as sold by Moss a reasonable option?

Secondly they list both pos and neg earth versions but the pos earth version costs £70 more! Is there any real reason why you can’t just buy neg earth version and just wire wrong way around, taking care of course with how you do this of course. I suppose it can comes down to whether it needs to earth through the body, and whether body of fan or any other component is life.

Quick responses would be appreciated.

Paul
Paul Dean

My money is on a radiator shroud
Bolney Coupe

Bolney.

I am afraid shroud doesn't help in this case as what I want to do is move fan in front of engine due to limited fan clearance in normal due to early 1800 engine bringing fan forward.

By the way I do have a shroud if anyone wants it as I found it noisy and awkward although in theory it is the right way to go.

Thanks

Paul
Paul Dean

Hi Paul
the clearance problems on my 1800 set up were solved by fitting some spacers onto the rad to move it forwards.
This moved it forwards enough to clear the engine driven fan.
I fitted an engine driven plastic fan sold by NTG which worked brilliantly, it dropped the running temp by about 10 degrees too. But it was a bit noisy in operation which is why I then looked at electric fans.

I experimented with a Revotec 10" electric fan after removing the engine driven fan but to be honest, its cooling performance on my MGA was marginal at best. It has some beautifully made brackets but I wonder if they block the airflow a little. Also they are not easy to fit.

The car ran almost 10 degrees hotter with it fitted which I think was due to it not running all the time like the engine driven fan does.
But my concern was that the fan struggled to bring the temperature down in traffic, it often went over 200 degrees.
I managed this better by switching the fan on before the temperature gauge rose higher than I was comfortable with but it wasn't ideal.

Personally I think a single electric fan works better in combination with an engine driven fan.

You may have seen in the earlier thread that I now have a twin 9" fan set up which works FANtastically.

It is fit and forget and it controls the temperature perfectly. I have had it fitted for a few years now and it has coped well with ambient temperatures in the mid 40s Centigrade in the mediterranean region.

So if you wish to go the electric fan route, I would definitely recommend the twin- fan set up.

Cheers
Colyn

PS I have sent you a PM with more info.
(See you in Ilkley next week?)
Colyn Firth

Paul

I thought your car ran cool. why the sudden urgent need to fit a fan?

Steve
Steve Gyles

The reason for this urgent interest is the end of very long and now positive saga starting last August. Full story next week.

The relevant bit here is I had a recored radiator fitted by someone else. By the way as Colyn my radiator had been spaced forward since I went 1800. The result of this is that at the refitting the spacers were left out and guess what it destroyed new core. I have a photo but too big to attach. What appears to have happened when I reved the engine for first time two of the fan blades caught the bottom tank of the radiator that protrudes further than the core. The blades bent severely and then scribed a perfect few mm deep circle well into the core. It also cut into the bottom tank. This was yesterday morning.

I got the radiator out (easy when it only went in 2 weeks ago) and took it to people who had recored it and they are doing it again and fixing the bottom tank, and all for tomorrow lunchtime. The result of this I realise that even with spacers I must have always since going 1800 have been very near to the bottom tank hence my idea of taking the fan in front of the radiator to completely avoid the issue.

I now won't go the Revotec route based on what Colyn says so I will get the spacers back in. Thankfully I do have a spare fan so I will fit it but ensure none of the ends of the can touch the bottom tank. Interesting on the old mangled fan only 2 of the 5 blades touched so not all positioned quiet the same. I hope Steve never had this issue with jet engines!!

Fuller story next week.

Paul



Paul Dean

That's such bad luck Paul (and even worse timing),
it must have been a horrible moment when you started up the engine.

Fingers crossed that it is sorted out soon for you.

Cheers
Colyn
Colyn Firth

Paul

By spacers I presume you mean the long rubber packing strips? The bottom tank on my radiator is flush with the core. Are you sure you have an MGA tank? I also run the 1800 engine and the fan blades have 1 1/8" clearance with the tank core. Even without the spacers it would be 1 1/16".

Steve
Steve Gyles

Yes I had two sets of the rubber strips to give the extra space. The radiator structure certainly came with one of the 2 As that I bought in 69 and 72. And Bob West never suggested it wasn’t standard. Based on what you say I think the last core was probably just mounted a bit back rather than the tank sticking out. By the way your spacing issue may be different to mine as my engine is a 3 bearing one where the pump certainly come quite aa bit further forward. I will see how things go when I get rad back tomorrow.

Paul
Paul Dean

Hi All,
you have me worried now as I fitted an 1800 engine earier this year and refitted the 1600 metal fan with a new water pump. The car does not get hot and the fan has not destroyed my recored radiator. I have an inch of clearance between fan and rad and did not space rad forward. Should I have done?
s page

i would say an inch is fine. by the way which 1800 engine is it?

Paul
Paul Dean

Paul

I suspect you may have the correct top and bottom tank but the re-corers have put in a narrow 2 row modern core which is no good for the MGA. For efficient cooling you need the traditional 3 row MGA core often discussed and in the archives. By the sounds of it you have the extended length water pump shaft (albeit a standard MGB option) instead of the short one that gives 'S' and myself the additional clearance.

Steve
Steve Gyles

Hi. The engine is a 5 bearing relatively late block. I cant remember the exact engine designation but can find it if it matters. I asked Autorads in Luton who put modern 3 core rads into my racing Sprites to do the same with the A rad. The engine now has 105+ bhp at the wheels( Peter Burgess's rolling road) and sits around 180 degrees and isnt bother whether hammering around or pootling around country lanes.
s page

For the moment I have to progress with the rad I get back tomorrow. If I have to I will revisit the issue later.

It would be of academic interest to know if all versions of B engine and pumps are same. At a quick check there are 3 different pumps for the 3 versions of the B engines. Certainly in my case the pump on 18G/GAs is longer than that on a 1500 A. My measurements by the way are in a thread from 3 years back which I may try and find.

I will update when some progress.

Paul
Paul Dean

Paul

I run an 1800V with a short pump shaft.

I measured the width of my close to original radiator core from Bob West and it is 2 1/4". My thoughts are that unless you get the core design right you are up against it for cooling whether you go mechanical or electrical fans. So many people with cooling problems put plaster on the symptoms instead of diagnosing and treating the cause. In your case of course you said it is a fan blade fouling problem rather than overheating.

One other thing that puzzles me though is that I thought the radius of the metal fan blade does not extend to the bottom tank so I do not understand how it hit it. I have the 7 blade asymmetric fan (brilliant) on mine so do not have a metal blade at hand to measure. Probably in the loft somewhere.

Steve
Steve Gyles

Before the radiator went back I checked measurements and the fan is longer than the height of the core. I think the core is 11in and the fan is 12in. I have never heard of short shaft pump, where do they come from? May not be one for 18G/GA engines. Also I suppose same question for asymmetric fan, and what diameter is it?

In short term I am not too worried about 2 row in ‘cold Scotland’ although I did have a Bob West one before and in long term may go back there. Although much discussion here there must be lots of As running on 2 row radiators and getting away with it as they are sold so widely.

Thanks.

Paul
Paul Dean

Paul
I have an 18V with its standard water pump and there is plenty of room between the standard steel fan and the rad core. I believe the 18V has a shorter pump then the earlier 1800s. No idea whether these are interchangeable.

Cheers

Dave
Bolney Coupe

Paul
I have an 18V with its standard water pump and there is plenty of room between the MGA standard steel fan and the rad core. I believe the 18V has a shorter pump then the earlier 1800s. No idea whether these are interchangeable.

Cheers

Dave
Bolney Coupe

Paul

I stand corrected on fan diameter. I could not see properly in the dark last night. My fan does overlap the bottom of the core. This is my fan: https://tinyurl.com/ydcf84fx

You can see in the pictures the significant clearance between the fan and core.

For some odd reason I cannot find the pump receipt which I bought from a racing midget/MGB engineering workshop in Preston (now relocated and I cannot remember his name). I do recall him saying that it was the short shaft pump I needed for the 1800 in an MGA. Looking through the Moss catalogue I cannot be certain. However, the faceplate is drilled to take both the original MGA fan and pulley and also the MGB.

Steve
Steve Gyles

Paul

The pump I have used on my 18V engine in my MGA1600 is the GWP130.

I am running a Moss replacement MGB crankshaft damper pulley (and that of course sets the plane of the fan belt), and the pump has the larger diameter pump pulley, as recommended by Peter Burgess, to have a slower pump speed.

I have not used spacers, only the thickness of the plastic Moss fan shroud, and I am using the original MGA 1600 metal fan, which sits about an inch from the radiator.

Although the radiator was re-cored many years ago, with a non-original pattern core, I experience no overheating ever. The car sits on 82C all day, in any conditions, only rising once to 95C on an extended alpine climb in heavy traffic in low gear (San Gottardo - first day after the winter close and everyone was heading for the summit).

Your fan interference problem may be related to both pump choice and pulley offset. With the GWP130 and a short offset pulley you should not need spacers under the radiator mounting to achieve sufficient fan clearance to the radiator.

Regards
Mike Card
M D Card

Hi All

Hopefully to put this thread to bed for now. I am back on road with sufficient clearance between fan and widest point of radiator. Had a good long but fairly easy run without any issues. I am doing 500+ miles next weekend to MGCC MGA North weekend in Ilkley so will report if I have any problems. My family by the way think it is funny going 200 miles south to get to a ‘North’ event!

I had a long chat with the guy who did the recore. He believes the special 2 core he fitted is about 85% as effective as the Bob West 3 core he took out. We will see. By the way he is the only radiator specialist now in Edinburgh and he has been doing them for over 50 years. He certainly know the subject inside out and even recognised mine as an A radiator before he was told.

It would appear the pump clearance issue that is present with my 3 bearing 18GA engine isn’t present with 18V engines.

Thanks for help.

Paul
Paul Dean

Glad you have fixed it Paul,
hope your "cool running" experiences continue.

See you in Ilkley

Cheers
Colyn
Colyn Firth

Enjoy.
Steve Gyles

Paul, Colyn,
On your Ilkley trip, could you please ask any Twin Cam MGA participants for a photo of them and their twin cam with a nice backdrop and a short caption to go with the photo, if they are willing, please?
I am compiling a “2018 Yearbook” for the MGCC Twin Cam Group to mark the 60th Anniversary of the launch of the car and one section will be “Owners out and about”.
I would need at least a 500kb image, the date and location/event and all material can be sent to colinmanley99@gmail.com.
The book will be published towards the end of the year and publicised in the MGCC “Safety Fast” magazine.

Likewise, anyone reading this, by all means do likewise.

Many thanks in advance.

Regards
Colin
Colin Manley

Yes fine. Good excuse to talk to TC owners. I am told even away from their cars you can identify them by scars on their arms.

Paul
Paul Dean

Paul

I second that. I was forever scraping my arms from cleaning/working on my TC. Bonnet locking levers was one area; the other was round the front with the badge bar/spotlight/horn.

Steve
Steve Gyles

Will do Colin,
I will just have to try to not let my Twin-cam envy show too much.
They really hate their cars being drooled on you know :-)

I hope Steve has not invested in too many batches of bonnet locking levers to sell to Twin-cam owners! :-)

Cheers
Colyn
Colyn Firth

I was asked last night how to seal the top hose when using a temperature sensor in the hose. As I have never used this arrangement (I tend to rip the fans out and solve the underlying problem) I don't know the answer, but as this owner wants to keep his fan, what is the trick to prevent leakage here?
Dominic Clancy

Dominic, I have a sensor in the top hose. If I remember correctly, I just loosened the hose, slipped the sensor in and tightened up again. No leak.
Shane
Shanerj

The sensor in the top hose came with a small moulded rubber piece, tapered at the edges and with a groove for the tiny pipe to sit in. I placed the hose-clip directly over this and gave it a good tighten -- the hose took up the slack with no leaks.

Barry Gannon

Dominic
I used the Revotec in-line thermostatic switch to fit into the top hose, (picture below) it works fine with no leak issues. There is a slotted adjuster under the rubber cover to let you adjust what temperature you want the fans to switch on at.
I have run this for a few years now and I am pretty happy with it.

Alternatively, Davis-Craig make a similar in-line fitting that is designed to fit a sensor probe which may be worth a look at.

http://daviescraig.com.au/product/temperature-sensor-adaptor-kit-0409/temperature-sensor-adaptor-kit-0409


I'm kind of surprised that you haven't gone down the twin cooling fans route Dominic.

I know a single engine driven fan works fine on a correctly set up B-Series engine (my NTG fan cooled the engine superbly), but the NTG fan used up to around 6 bhp and so I thought that replacing this with twin electric fans was a really easy way to get that kind of power increase.

I know that when the twin fans are running, they still use the same amount of bhp as the engine fan did, but as my electric fans scarcely ever run, this gives a "win-win" situation.

Would be interesting to see what Mr Betson thinks?

Cheers
Colyn


Colyn Firth

A much simpler, unobtrusive and effective solution for the temperature sensing element is to use the Kenlowe slotted sleeve which fits in the radiator end of the top hose. Mine has never leaked and is such a neat arrangement compared with all the previously mentioned in-line adaptor ideas, imho. The Kenlowe sleeve only costs a few quid and is available from many of the usual suspects such as Holden, etc. Keep it simple!
Bruce.
B Mayo

Thanks Bruce, that's the solution I think will be best (apart from resolving the underlying problem of course)
Dominic Clancy

Yes, thanks Dominic. Just to explain - I’m not an electric fan enthusiast as others above going for twin fans, etc. My Twin Cam cools very nicely with standard setup, including 39degrees in Le Mans last summer. I have a small old Kenlowe fan without shroud in front, just as absolute backup should a long hold up in hot traffic ever arise. Hence the nice simple Kenlowe sleeve for an almost invisible installation.
Bruce.
B Mayo

You can run the shorter MGA pump in a 3 main MGB block and apparently don't lose much despite the impeller being smaller diameter.

Anyone having the fan in close proximity to the radiator core for whatever reason would be well advised to source an MGB limiting bracket that bolts on top of the RH engine mount and limits forward movement of the engine.

Moss 413-075

https://mossmotors.com/recoil-bracket?assoc=62088
Bill Spohn

My roadster engine is 3 brg 1800. Engine fan has 20 mm clearance from radiator core, no spacers. See pic
Mike

Mike Ellsmore

Anyone know how you source the supposed short pump in UK? Also does restraining bracket fit, is it standard on all Bs?

Paul
Paul Dean

This thread was discussed between 01/05/2018 and 26/05/2018

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