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 Midget and Sprite Technical - how much space for a electric fan on 1500?

Hi All,

I've read thru the archives but I struggling to work out how thick an electric cooling fan has to be to fit behind the radiator on my 1500 midget. At speed my temp is bang on N but raises in traffic and I'd like to get it to stay closer to N.

Most of the fans on the market seem to be 55-65mm thick, even with the engine driven fan removed I dont think it will fit between the fan pulley and the radiator. Even the ones on MGOC are 56mm.

I guess I'm asking which specific fans people have fitted in this location as a 'puller' or do I give up an fit a 'pusher' in front of the radiator instead, again what size fits?

I should have checked this at Midget 50 and made a choice before putting the new radiator in. DOH!

Thanks,

Richard
r parker

You can fit one easily(ish!) infront of the radiator, which is a better place anyway!

Take your car to the local scrapyard and ask them what they have available - they might even have some narrower ones - vauxhall ones can be made to fit with a little bit of cutting of the wasted plastic.
rachmacb

if you don't use your car in the winter or on very cold days (apart from the fact you could still be missing greater driving days or times) then as rach says a fan in front of the rad could be in addition to to the engine driven fan

check the fan suck/blows in the correct direction (easy if you're a smoker)

you could fit it with a thermoswitch or manual switch or both if you don't trust the thermoswitch and/or yourself
N Atkins

I think kenlowe makes one that can fit the midget, I know they advertize it as both a pusher and a puller

Personally im a "fan" of the puller myself, I belive we need every once of air we can get thru the rad to cool the coolant, where as a pusher gets in the way of airflow...just my opinion

I think you can get a thinner pully to give more space...but I dont know the details

Prop
Prop

The 1500 Midget is a wee bit marginal on cooling because the rad really isn't big enough, and the bumpers restrict airflow into (what is a rather hot) engine bay.

TBH the LAST thing you want to do is put a fan in front of the rad because it will further restrict flow.

Clova and Davies-Craig make some thin housing fans that would fit. Failing that, you could grind down the original fan mount.

I wouldn't touch Kenlowe stuff with a bargepole!
Deborah Evans

Prop, there's also Revotec over here

Richard, I assume on a 1500 being about N is normal, so you could allow for gauge variance/error

items that could be checked:
sufficient coolant
correct and renewed oil and coolant at services,
correct coolant mixture ratio,
correct tension on fan belt,
clean coolant system - engine block, heater matrix, rad, heater vavle, hoses, pump
debris on front of or blocking rad
water pump worn,
engine idle too low
N Atkins

just seen Deborah's post - I was as usual typing as whilst others are posting

so, even more important to have you original system in good working order then, but then when isn't it

my 1275 with a crossflow rad and very clean coolant system (rad to come off yet again soon) actually runs very cool whilst moving then quickly warms up when stationary but still never quite gets to N - rach'll say that's what you get for having a 1275 :)
N Atkins

I still have the old vertical flow rad on my 1275.

I fitted a Datsun cherry (C.1983) electric fan in front of the Rad. I Never noticed a restricted airflow problem.

I don't know about the 1500's maybe they do run hotter.

Wouldn't surprise, me as the rad on the Triumph 1500 saloon, was quite a bit bigger and that ran hot if pushed.

I have mine on a manual switch on the dash and only need it on VERY VERY hot UK summer days, in stop/start traffic. I fitted it to drive in North Africa and Spain, but rarely use it in the UK.

Make sure you don't have all kinds of air flow obtructions behind the grill, such as wiring, and badges on the front of the grill etc.

I've often wondered if there is a way to vent the engine bay more efficiently, through a grill, perhaps a reversed air scoop. But haven't wanted to spoil the nice long smooth bonnet.






Lawrence Slater

Thanks Deb,

TBH, I dont know anything about kenlowe, other then there adverts, so as always, ill take your word as fact from gods mouth to my ear...hahaha

On a somewhat related / unrelated topic....how do I get the engine TO HEAT UP....Im having problems getting it to heat up past 120 degrees F.

Im not sure if its the 160 degree stat with 4 holes drilled in it, the 25/75 coolant ratio, the water wetter, or it could just be the special aluminm racing double pass radiator that was maximized to take full advantage of the air flow

yeah, lifE is tough trying to figure out how to heat up the engine when the temp is around 100 degees F. outside

Gee, what am I to do, anyone else share my issue, what no body im the only one ..... Hahahaha

Thank god for card board and duck tape, ...haahaha

PROP...home of the 10 gauge radio consel
Prop

Lawerance,

Its called fender vents, and a certian some one on this forum with the initials CB thats a formula 1 .....oh well, im sure he is still busy after 3 years...hahah just kidding carl.

lawerance there have been several of us working on just such a topic, but has proved difficult to design a COST effextive fender heat vent thats easy to install....but im sure we will crack the code eventually.

Prop
Prop

Richard

Also check that a PO hasn't fitted a pre-1500 front valance with no ventilation holes.
Dave O'Neill 2

Ah fender vents. So that's what they are called. I guessed it couldn't be that simple or someone would have done it by now. I mean, you could just cut a hole in the bonnet, but that would look terrible and let the rain and rubbish in.

What would be nice is a hinged affair, maybe in the region above the exhaust maniflold, controlled by push/pull cable (or motor), that would close flush with the bonnet with seal when not in use. Finished in the same colour as the bonnet paint.

But sounds more of a problem, than just dreaming of how it would look. Aint that life. lol.

Lawrence Slater

Hi All,

Thnaks for the feedback, I'm getting the feeling that N on the gauge rising a bit in traffice is actually OK. My gut feeling is that (as Deborah says) any more blockage in front just feels wrong.

The engine warms up just fine and maintains a steady temperature except in traffic. I gave it a bit of a flush when I put the new radiator in the other week. I also replaced top & bottom hoses as they were looking a bit sad. I think everything else is pretty standard but you've now got me wondering, as i did not check the thermostat and will need to look at the valance to check it has holes!

Come too think of it I also actually have no idea what N on the dial means in real numbers as the temp gauge is off a landrover, a standard UK style Smiths gauge as the dual one only reads Oil pressure these days.

I can put a thermocouple on the radiator tank and get a temperature measured of that when the gauge reads N, anyone have a clue what sort of figure I should be expecting there?

Maybe I could out gauge Prop, with a 10 channel digital thermocouple reader mounted in the dash, unfortunately I work would want it back!
r parker

If anybody asked me, I'd advise them NOT to fit an electric fan to a 1500 Midget. Airflow is too restricted, both through the front grill and in the engine bay. And the rad is too small.

Interestingly, when I did a couple of comparison rolling road tests, although marginal results, I got more BHP (approx 5% I recall) from the engine with the engine driven fan fitted compared to having the electric fan working (albeit a Kenlowe). We explained it by the engine driven fan better controlling the underbonnet temperature giving more stable fuel supply (lower temperature around the carbs).
Andy Hock

Andy,

Was that the early (fixed) fan or the later (viscous coupled) fan?

Richard,

Ideally on a Triumph 4-pot you should be looking for 95-98 degrees C - any hotter and you run the risk of killing the motor, any cooler and you are not getting full efficiency.

I would fit a cooler 'stat and up the header tank cap to one of 15 lbs.
Deborah Evans

Deborah,

Many thanks, have just orded 82° thermostat and 15lbs cap form MGOC. I like the idea of trying some standard part fixes. I'll get a measurement or two to see what the numbers are. The sun's out so maybe tonight....
r parker

I thought 15lb was standard - but I'm not a 1500 owner and often wrong

if you've put standard top and bottom rubber hoses as unless things have improved they may well start to get surface cracks after 9 months, well my first top hose did

draining the engine block is often forgotten and sometimes opening the heater valve

rather than putting in a lower thermostat I'd sooner a good clean and flush of the rest of the system and coolant change all cheap an easy and not sure a chore in the warm weather, almost a pleasure if the sun is really hot

copy and pasted:

For a coolant change drain the whole system - engine block, rad and heater matrix if you can get any of these out to give them a good shake at the same time as flushing and back flushing then all the better - the sequence is use cleaner as per its instructions then flush, back flush and flush and continue this until water runs clear, refill with the correct coolant mixture but bear in mind in tap water isn’t always the best water to use

If you clean the whole of the coolant system and also renew the seals and foam around the heater matrix you will find the heaters can get very hot
N Atkins

"rather than putting in a lower thermostat I'd sooner a good clean and flush of the rest of the system and coolant change all cheap an easy and not sure a chore in the warm weather"

Nigel,

At the risk of being 'sharp' with you, I've been playing with these engines for 30 years (both stock and tuned), so I rather think I know what I am talking about. After all I run a business building the bloody things!


"I thought 15lb was standard - but I'm not a 1500 owner and often wrong"

Stock cap for a 1500 is 13 lbs.



Richard,

I would flush the system properly and change all the hoses for Nitrile or Silcone. Be careful you bleed all the air out on refilling (and they are a pig to bleed!)- I fill the system through the thermostat housing but with the rad overflow disconnected.

Start up and run to temp. Allow to cool, remove overflow pipe and refill.

Oh, and use premixed OAT (pink) coolant (but make sure you use a rad flush first!).

Oh and if you have the plastic thermostat plug replace it with a Brass one (and a new O-ring),


1500s are critical on cooling - run them hot and you'll knock a big end out.
Deborah Evans

Has anybody tried using evans forlife coolant in a midget it is supposed to help engines run cooler and better
mark (1977 1500 Midget) Preston Lancs

iv just fitted a mk3 polo radiator to my midget seams to cool alot better with stock fan. but im going to try the 12 v fan off polo as it will spin faster all the time not like the midget one and slow down the airflow when its ticking over when u will need it most, also if the timings out or carbs are running lean it will run hotter.
james gibson

no but if it works I llike the sound of it

I've used the other 4-LIFE engine coolant for many years, I mainly like it as it shows up leaks well and where there coming from, nipped up a connection here, gasket there

I should have bought shares as everytime I put some in something happens that invovles the coolant system, more like 4-NOW for me

you use it undiluted and I learnt this year it's not good in old engine that haven't been rebuilt or reconned within a few years (don't know how many years tho')

http://holden.co.uk/displayproduct.asp?pCode=080.861
N Atkins

following on from James the engine driven fan also works against the engine when starting from cold and especially in cold weather

all my eggs are in the electronic cooling fan basket with thermoswitch and no manual over-ride switch either - I'm sure I'll pay for this recklessness . . .



many, many years and tens of thousands of miles in the future - if not I'll let you know
N Atkins

I have a gallon of 4-life to try on a Climax engine - watch this space.

HOWEVER

It is UBER aggressive and WILL find any leaks in the system.


Overall, my current recommendation is OAT Coolant (which is lifed at 5 years).
Deborah Evans

it was probably you (Deborah) that told me about it with old engines

I've never personally had problems with it

knowing my mate I'm pretty sure the 4-LIFE the manufacurer put in his car nearly 20 years ago, before his ownership, will be the original despite it's claimed 10 year life

the car was left running stationary in hot French weather for at least 3 hours with just the occassional blip of accelorator the keep the oil pump spinning, temperature steady as a rock

he didn't want to turn the engine off as we were at the Loan event and did't want a third jump start off my Midget (all must have thought it was for the other way round)

Japanese make good cars and good engines but the Italians don't make the best car batteries, he's still got the undersized "french" on the car, they were so expensive to buy other there
N Atkins

Richard,

I've got a Revotec from a Mini - I think it's an 8.5" fitted in front of the rad and is a pusher. Have removed the mechanical fan. It came with a thermostat. I'm about to fit a manual override just in case.

Jeremy
Jeremy 3

You also need the air to go out and for this a simple solution (prop don't read this!!) is to put a few holes on the outer wings - nice and neat and unobtrusive!

My 1500 has only once got anywhere near N and that was during an autotest on a very hot day and had been running between flat out and idle for ages.
rachmacb

To late rach....hahahaha

Actually Mark T cut 3 holes in his fender and put a mesh behind the hole...it looks nice for a race car, but im not sure iof I like that idea, Im thinking something like the cobras, and sting ray corvettes...maybe even the 79-80 camero...the angled rectangled box

Prop
Prop

Jeremy, I've just read another of your posts where you happily rely on modern electronics but keep the old bits in the boot now you're fitting a manual override switch - are you of a nervous disposition ? :)

rid your yourself of anxieties and your boot of weight, throw your trust fully to your logic, free yourself from procrastination, commit to your beliefs

:)
N Atkins

I was looking at using Evans NPG+ coolant which says on there site it is suitable for small engines and older/vintage cars and offers the following benefits

Important Benefits of NPG Coolant:
For Gasoline Engines:
• Higher Gasoline Efficiency
• Reduces Emissions
• Higher Compression & Power
• Knock Reduction
• Improved Octane Tolerance (lower octane fuel usable).
• Reduction of Hot Spots (Critical Metal Temperatures)

Secondary Benefits of NPG Coolant:
For Gasoline Engines:
• Non-pressurized: (or low pressure, i.e. 4.0 psig) decreased leaks, lower pressure parts, decrease of thermal flexing or cycling (component life extended), elimination of accidents resulting from accidental removal of radiator caps from hot engines.
• Allows for a totally closed system (Hermetically Sealed) requiring no service checks and is not subject to contamination.
• Improved stability of engine operating temperatures.
• Improved aerodynamic styling. The radiator no longer needs to be higher than the engine and can be placed anywhere.
• Weight reduction possible if higher coolant temperatures are used. Smaller radiators, less coolant, light-weight metals (such as magnesium for engines), small cooling jackets in the engine, smaller fans.
• Decreased duty cycle of coolant fan for the same coolant temperature by allowing for higher temperature excursions for short intervals with no adverse effects on the engine.
• Faster combustion chamber metal surface warm-up, CO reduced in start-up (liners get hot faster) mostly because of lower specific heat of cold NPG.
• Elimination of premature spark plug failure and head cracking by better cooling of head.
• Reduction or elimination of pre-ignition and detonation:
o Reduce head distortion and cracking at high compression and supercharged / turbocharged boost levels.
o Reduce head gasket fire ring failure.
o Reduce piston dome and ring failure.
o Reduce valve face sinking ("tuliping").
o Reduce rod bearing failure (caused by cylinder pressure, detonation related, spikes).

mark (1977 1500 Midget) Preston Lancs

Hi All,

Wow, so many options to try and things to think about that I've never even worried about before, thanks you all so much! The plan so far is to take Deborah's advice and change thermostat & radiator cap. I will attach a thermocouple to the radiator and take some before and after measurements. While I'm at it i'll give the rest of the system a good looking at, I think its Ok but now I have list of new things to check.

I did check that the front valance has holes in it, it does, but they are right behind the numberplate. I feel a stick-on plate coming up.....

Thanks to all suggestions I'll update my progress asap.

Richard
r parker

Why not just good ol fashion vary common green glyco....cut it to around 75-80 to 25-20 water to coolant ratio and a cap full of water wetter for summer driving


Prop
Prop

>>Deborah asks>>Was it a viscous or early water pump.

>>AH replies<<Deborah, it was/is an early water pump, fitted with the BL 'hot climate' plastic fan blade, purchaed in 1979. I kinda brought the 'running too hot' problem on myself - back in the days when I was young and keen, I fitted out the engine bay with bitumenised sound deadening felt, including under the bonnet. Irrespective of that, as rachmb says, there's nowhere for the hot under-bonnet air to escape, without resorting to using a tin-opener on the front wings.

I am currently using Red Line 'water wetter' which helps a bit. (Also, have been using an oil cooler with full-flow Mocal 'stat since 1980).

But definitely don't remove the engine driven fan on a 1500. Well, my 1500 anyway!
Andy Hock

'Why not just good ol fashion vary common green glyco....cut it to around 75-80 to 25-20 water to coolant ratio and a cap full of water wetter for summer driving'

Because:

a. OAT has better coolant properties.

b. Running old fashioned glycol coolant at that sort of concentration will rot out the hoses in about the square root of no time!
Deborah Evans

interesting stuff as always on this forum!

I have to admit to being surprised that the 1500 is marginal on the standard rad - My K series is absolutely fine on it. It has an electric fan in front of the radiator as well.

I found that the A series mechanical fan did nothing over 20mph, found this out as someone had put a mini one on the water pump - they blow away form the engine, so mine was blowing out of the front.

Result was huge overheating at 20mph but fine under and over. So my conclusion was that the airflow was enough to beat the fan and cool sufficiently over 20mph, so the fan is wasted energy at that point and might as well not be there.
Rob Armstrong

"I have to admit to being surprised that the 1500 is marginal on the standard rad - My K series is absolutely fine on it. It has an electric fan in front of the radiator as well."

The K Series isn't as marginal on internal temps and oil film breakdown as is the 1500 (especial the 1.4 K).

Furthermore, yours is a RWA car so you don't have that bloody great piece of iron up front blocking flow through the grille!


The only 1500 Midgets that I have seen run at the N level are those that have had the bumper removed (or a chrome conversion).
Deborah Evans

Lol then I shall expect mine to run at C all the time .....!
rachmacb

Like Deb says my 1500 also never did had heat problems with bumpers removed and oilcooler.
Mine was an ex US with a wider radiator tho.


Arie de Best

"Mine was an ex US with a wider radiator tho."


Probably one of the best mods you can do to a UK spec car (other than an oil cooler) - I do a similar thing with tuned Spitfires and use the full width US spec rad.
Deborah Evans

I've never had a problem with my tuned 1500 whether driven hard or stationary and it still has it's rubber bumper on. Standard rad, thermostat, cap and oil cooler.

Les
l snowdon

Richard,

I put a pusher fan from a Toyota Corolla, 1990 I think, in front of the radiator on my 1500 and it works fine, although I never use it.

I had my radiator boiled out and use 50/50 mix of green glycol antifreeze.

I just did a 200 mile trip on the interstate at 65 mph in 90F/32C heat and the temp stayed right in the center.

The only time I've used the electric fan was while in a parade at walking speed, but even then I didn't really need it.

A good, clean radiator is more than sufficient.

Lee
Lee Fox

Hi All,

So after some testing I'm even more confused!. I ran the car yesterday with a thermocouple wedged in the (new) radiator fins. Stationary in traffic the temperature at the thermocouple rose to 50°C, on the move it dropped to 26-31°C. All pretty promising. The dashboard gauge read bang on N on the move rising to a little above N when stationary. Today I've replaced the thermostat to an 82°C one and added a new 15lbs cap and flushed the system out some more. I also replaced the carbuettor heatsheild. With the thermocouple in the same place in the radiator I'm seeing pretty similar temperatures perhaps a bit lower on the move, BUT now the dasboard gauge reads almost halfway between N & H. Arrgh!

The engine bay seems cooler and the dash gauge is steady at this new position, not rising when stationary, but I guess I need to do more tests to work out what the actual water temperature is. That or just buy a new gauge & sender!. I'm letting it cool down and will go and check again to see if there is any air in the sytem ( I bled it as per Deborah's instructions)

I think I will have to see if the thermocouple is waterproof and lodge it under a hose in the actual coolant to get a accurate reading of the coolant temperature rather than rely on the dash gauge. What temperature should the coolant be at anyone?

Thanks

Richard
r parker

ok, I give in. Still cant find any air, I've checked the wiring of temp gauge, all seems OK. I've just ordered a digital temp gauge and sender, its the only way I'm going to get this bottomed out. If I put the thermocouple in the coolant hoses I'll only have to remove it again, this way if it works I'll just leave it alone! While I'm at it I may get a digital oil pressure gauge. Anyone fitted one? At least this way I'll remove the doubt about dodgy gauges & old senders!
r parker

Richard,
let us know the outcome please

Deborah,
sorry I’ve only just seen a post from you (well back now) addressed to me

I thought the ‘rad’ caps for 1500s are 15lb, I did put I could be wrong and I didn’t own a 1500, I wasn’t questioning your knowledge although you could have made a typo

I’ve found where my thought came from:
Page 71 of (1982) copy of Haynes
Filler cap pressure – later 1275 cc, and 1500 cc models – 15 lb/in

Also on checking:
MGOC Spares web page -Midget > Cooling > Radiators / Hoses (Midget)
68 - Radiator cap- 15lbs GRC110 [68] More

Moss and Sussex also have 15lb

(factory) Parts Catalogue (AKM 0036, February 1977, 1st Edition), page 86 shows
part GRC 110 cap-filler, GRC 110 seems to be 15lb

Also I’ve just seen the same mistake is in the Haynes that you quite rightly pointed out was in the Owners Handbook about the steering rack on later cars needing grease rather than oil, see Haynes pages 12/13

Yes I do find some of your posts a bit sharp and even prickly but I used to it now, I also seem to put posts that are a bit blunt at times when they’re not usually meant to be that way – you can be as blunt as you like with me but others may be a bit more sensitive, as you can also be at times

nothing wrong with disagreement as long as the facts help those that view the BBS
N Atkins

Hi All,

Latest update, shiney digital gauge arrived today, so ready to fit.

I think I may have accidentally found the problem. Before pulling the old sender out I checked the level in the header tank, all Ok. After fitting the new sender adaptor I topped the system up only to be met with the depressing sound of dripping water. I traced this to the 'bottom' of the headertank and so thought it must have a crack perhaps due to greater pressure or something. Anyway, with the tank removed, coolant runs freely out of the drain hole on the side of the neck. The metal insert at the top of the hole for the cap is badly corroded underneath and has distorted the neck preventing the seal seating properly. With the new cap it seems to only seal under certain conditions so I guess I've not had a good enough pressure seal on the system. I think I've been lucky as it only took about 3/4 pint to top the system up again so I dont seem to have lost too much coolant.

So, I'm off to get a new headertank as the neck is pretty bad and is not worth trying to save.

Next installment, new headertank, gauge, and some more pipes just for good measure.......
r parker

This thread was discussed between 06/07/2011 and 12/07/2011

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.