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MG MGA - Electric Fan-Puller type

I bought a cheap 10in fan on Ebay and it lived down to its price--it was too big to fit in front and too fat to fit behind between the pulley ( without mechanical fan ) and radiator. I have fitted and wired all the thermostat controls ( Robert Shaw ) so will proceed and get a better fan. I would prefer a puller as I believe there will be less interference with natural airflow at speed but the gap between pulley and radiator is only about 4cm ( setting fan slightly to one side away from central pulley boss ). Has anyone installed a puller ..or know of a fan that will fit? If neither available what fan do you recommend for a front neat fitting ...one with a proper fixing ( not tie wraps or bolts pushed throgh radiator ). I know there is a pusher type on the Moss Europe site but it comes with the whole kit of thermo etc and costs two arms and a leg...any others around??
neil ferguson

my error..the thermostat was from Daves Craig..not Robert Shaw...
neil ferguson

Neil,
I installed a fan in front of the radiator and kept my mechanical fan. It is connected to the "F" switch on the dash and I turn it on manually when I need it which is only on hot days in slow traffic. I tested the car without the fan and with the fan (not running) to see if the fan caused a cooling problem when not in use and found no difference. The outside diameter of the fan is 12.25". Have a good day!


John Progess

John..thanks for advice and photo. I was working on the premise that the fan had to flush against the front of the radiator to get reasonable airflow through latter...this restricts the max dia to about 26.5cm ( 10.43 in ) because of the lip on the reservoir at the top.Comments?
neil ferguson

Neil, I run the Davies Craig 250mm. fan below. It works fine, fits the core below the header and is flush with the core. I have attached it to two aluminium straps across the width of the radiator and use the existing mounting bolts at each side. For a while I also used the "F" switch, but now have it permanently on. It starts and stops as needed, regulated by the thermostat which is housed in the top hose.
Barry


BM Gannon

Barr..your words are reassuring . After I posted the thread I kept on crawling the net and looked at Kenlowe, Revotec, Spal etc etc and finally determined that Davies Craig 9in was the best for me ..same size as yours...and have ordered. Queries....
..Did you consider it as a puller ( and would it fit )?
..Did you leave the pulley fan in place ?
..When you say two straps ..is that two straps top and bottom from each side?
...The staandard mounting kit penetrates the radiator..did you consider using it?
Regars
Neil
neil ferguson

Neil, I have mounted mine as a pusher - it is easier to reach and plenty of room in front.
I took the original fan off but found, on days of 40oC, that it needed both, so replaced it.
The two straps, aluminium from Bunnings, extend from side to side. I bent them to utilise the existing radiator mounting bolts. You can see one in the photo I posted.
Initially I used the mounting kit to push through the core!!!!! - not a good practice so I abandoned that. It took me a long time to repair it.
I'm happy to assist if you need two pairs of hands.
Barry
BM Gannon

Barry..thanks for the offer of help and all the advice ..but I am up in Narooma on Southern NSW coast right now with the car...lovely empty roads and driving around here.
I have decided to fit two of the fans ...both as pushers..to see if I can leave the old fan off altogether. Appreciate your advice re mounting..the through bolts looked a wee bit brutal for the radiator.
I have the radiator out right now for some repairs and a short filler kneck fitting ..latter is to allow me to fit a double seal cap and low pressure overflow/return bottle . I bought a Tudor windscreen washer bottle for this and have located in a cradle in front and to side of radiator.
...and just been advised that my Ford 5-speed conversion kit and gearbox has been shipped airfreight ex Hi-Gear Uk..very efficient and helpful company ( and thank god for the exchange rate !)
Had this car for 20 years and still modifying...got to keep busy.
neil ferguson

Neil, I fitted an overflow tank to my car and was under the impression that I would have to convert the rad to short filler neck, not the case though. All the long filler neck caps you can get off eBay seem to have the little return poppet valve fitted, so no need to change the neck. I used an MGB overflow tank on my A and it works a treat, radiator is always full to the brim. I could, if I wanted to, run the overflow tank as pressurized by putting the blanking cap on the radiator and the pressure cap on the overflow tank, but I prefer to run the tank as un-pressurized. Lindsay.
Lindsay Sampford

Lindsay...already had the amputation and transplant done ..only A$20 and I was having the radiator checked anyway..but good to hear about the efficiency of the system.It just seems too easy!! Is there any limit to the suction height from the bottle. I have set in down on the apron in front of the radiator in the washer bottle cradle..so bottle bottom is only just above bottom of radiator.
neil ferguson

Neil, it doesn't seem to make any difference where you put the overflow tank, just as long as the pipe from the radiator to the overflow tank is air tight and the end of the pipe in the overflow tank is covered with coolant it will work. The MGB overflow tank is quite big and that limits the places you can physically put it, but the Tudor type bottle should be easy. Just remember that you have to be able to top it up without getting coolant all over the place! I reckon one of the main reasons that MGAs have a tendency to overheat is that they seem to spit their coolant out at every opportunity, usually about ten minutes after you have arrived at your destination! So the header tank on the radiator is only half full most of the time and the top hose is not completely full of water which has to compromise the circulation. I know that the design of the grille doesn't help, but if everything else is working at full efficiency there should be no problem. Barney Gaylord says he occasionally gets up to the 230 degree mark on his car without any worries.
The overflow tank is probably the the best modification I have made to my car (thanks to the folks on this forum!). No more do I have people come up to me and say "is that water under your car mate?".
It make me wonder why it was not untill the MGB that BMC came up with the simple solution.
Lindsay.
Lindsay Sampford

Lindsay...can you not just top up via the radiator cap when system is cool and just let the overflow bottle do its own thing?
Looking forward to getting the whole cooling kit back together.....have just changed thermostat to sliding sleeve type set at 180c, installed electric fan temp control system ,new double seal cap, coolant recovery system,had radiator cleaned and tested , removed belt fan...and about to install two 9 inch fans ( will just fit side by side as pushers) and will set them up for on-off operation somewhere between 185 to 195c.
Hope to have the car back on the road in 2 to 3 days time to test it all out...ready for the Antipodes summer !!
neil ferguson

I have my 'pressurized' version of the MGB tank (as described by Lindsay) towards the back of the engine compartment in the same place as Mabel (early MGA race car) - see photo of Mabel (white bottle in front of Tudor bottle). Works fine and is out of the way of airflow through the radiator and to the front of the engine, including the carbs.

Steve


Steve Gyles

Neil,

If you have an overflow system using a recovery bottle you should not fill coolant through the radiator cap, always top up the bottle (but not full).
When you remove the radiator cap air entering will allow the coolant in the tube to run back into the bottle and some air to get into the radiator filler neck.
This should in time correct itself, as after several heating and cooling cycles the air should eventually be expelled through the bottle.
Best not to have this problem in the first place.

Mick
M F Anderson

Neil,

You say that you have a double seal cap. For a recovery system you need a triple seal cap.
One seal is at the top of the filler neck, one seal is at the bottom of the filler neck (spring type) and one seal is at the small poppet valve that allows coolant to pass back into the radiator.

Mick
M F Anderson

Neil, as Mick says, your rad cap must have a seal for the top of the filler neck, it's just a big rubber washer and can usually be fitted to your cap if it hasn't got one. Some caps have them and some don't, but they are usually interchangeable. You may find the rad cap a bit tight with an additional rubber washer, mine was, I just adjusted the two little latch pieces on the cap with a pair of pliers until I could turn it right down to the stop.
Lindsay.
Lindsay Sampford



MGB Mechanical yellow plastic fan.

I'm not sure what percentage increase it give, but it's certainly significant. If you still have problems, then get more technical.

Cheers
Mark.
Mark Hester

Bought a new cap with two rubber seals for radiator neck and poppet valve for vacuum reverse flow...when I put this in place I found the filling neck was too long and bottom rubber seal was not compressing ...so replaced the neck with a shorter one. All ship shape now..I hope !
neil ferguson

This discussion on seals and coolant recovery has made me question my own installation put in a few years ago especially since my seals do not have a poppet valve. The attached sketch submitted for any comments shows the arrangement that seems to have worked without any problems but I do have to top up the radiator from time to time and am not sure why this should be?


J H Cole

Your system is correct. It is the alternative method used on many cars, including more modern vehicles.
How much fluid are you losing? This can have many causes. If you are using an anti-freeze it often leaves a trace if there is a leak. The water pump seal is a common culprit, but there are many others.

Mick
M F Anderson

What pressure rating is your cap? Modern caps tend to have pressures too high for the MGA water pump and other components.
Even though your overflow tank is the pressurised type I would still fit a cap with one way poppet valve.
This allows easy entry of air during the recovery phase.


Mick
M F Anderson

John

Same pressurised system as I use. Are you using the MGB pressurised tank. Barney has previously questioned the integrity of this brass tank due to its age. Might you be losing the odd dribble through the welded seam?

Steve
Steve Gyles

MF: This discussion made me check the fluid level in the radiator and I ended up putting about 3/4 of a teacups worth in. I don't know how long its been like this and there is not surprisingly any sign of increase temperature due to this relatively small amount. The point of principle though - and I hope its only a principle- is that there should be no loss of water level in the radiator when cold. At first I thought I would find the awol water in the expansion tank thinking that there's a loss of low pressure when cooling preventing the water from 'sucking' back, but no the tank was almost empty. The hoped for advantage with this type of installation is that one does not have to keep monitoring the water level but I think I will now have to check it more frequently to try and see whats going on. I've done a 'cold' check for leaks and found nothing but I know that many leaks only happen when hot.
The cap is a 7 psi one.
Steve: yes the mgb tank is of very thin guage brass but I can't find any leaks -is there any history of leaky tanks?.
J H Cole

MF: I've just re-read your message and realise the point your making. As the water volume in the tank is sucked back by the cooling radiator it helps to have an air valve to stop negative pressure developing. Without this there could be 2 negative pressures fighting each other. The reverse is not true on filling since once the positive pressure reaches 7 psi the tank can vent via the cap. I bought the cap off Moss - I don't remember there being an option. Thanks for the clear thinking.
J H Cole

John, I have a similar system to Steve except that I run the MGB expansion tank as un-pressurized. I have the standard long reach 7lb cap with return valve on the radiator and the plain cap on the MGB tank. As I said before, if I remove the rad cap when it is cold, it is always full right up to the seal flange. The level in the MGB tank goes up and down according to the temperature of the system as you would expect. You could easily try it that way and see how it goes.
Lindsay.
Lindsay Sampford

Lindsey -where did you source the 7 psi cap with return valve, Moss say they don't have it? After you've said this I've been trying to justify running with a pressurised expansion tank and am struggling to find a good reason.
J H Cole

to return to the original thread..jut for a moment....I attach a photo of the two 9inch fans assembled as pushers on the radiator ( would not fit as pullers ). A neat but satifying fit and the size allowed me to secure one side of the rim of each fan through the radiator mounting flanges...all very secure and no holes through the radiator core...
Now back in the car and fits ok ....


neil ferguson

John, (excuse me Neil), I got it off eBay, return valve is not obvious but is a black plastic button in centre of the seal flange. I didn't realise it was a valve until I slipped my fingernail under its edge and popped it up.
Lindsay Sampford

Neil, I will wait to hear from you re the results of your two fans. I would not have thought it possible to fit two in such a confined space. Well done - it certainly gives me an option as I would like to be able to drive, with no detrimental effect on the motor, on days when the temp exceeds 40oC. Please let us know how it performs on the really hot days.
Barry
BM Gannon

This thread was discussed between 25/10/2009 and 30/10/2009

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