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MG MGB GT V8 Factory Originals Technical - Oil Coolers

I have just brought a 13 row oil cooler and since found out they were for Chrome bumper, I have a rubber bumper car, Is there any reason i should not fit it? Does it fit on the current fittings on the car? Will it effect anything? I am fitting a rover 3500 v8 will it be advantagous or should i go for the 10 row?

Thanks in advance
GLG Lavis

Have another look at the cooler you've got. The last one I bought had universal fittings. It could fit above or below the panel. The 10 row cooler is specified for RB & V8 & has to fit below the panel to make room for the fan/s unless you use a puller fan behind the radiator.The simplest way out is probably to exchange the cooler for the right one if the current one won't fit below the panel.
Barrie E
Barrie Egerton

Well, you'll get different opinions on this, but my strong opinion is you should return the oil cooler if you can get your money back because you simply don't need ANY oil cooler for a 3500 Rover motor in an MGB.

Omitting the oil cooler will simplify your installation considerably, eliminate potential trouble spots, and save you a significant amount of money. There are much more beneficial places to apply your time and money. The COOLING benefit of an oil cooler is marginal compared (for example) with the potential benefit of installing a good fan shroud or fitting RV8 style headers in lieu of block huggers.

I have a 1979 MGB with a 3.9 Rover LT77 trans RV8 Headers Edelbrock carb motor driven fan I hardly ever turn on my stock fans and it get into the 90's in southern Ohio. I think you will hear from a lot of people not using a oil cooler. Denny

The 13 row oil cooler will fit under the slam panel just fine, I have one on mine and even with the radiator ¾" farther forward, it still fits. See pics on my page.
As far as effectivity, it doesn't hurt to cool your oil as long as it doesn't get too cold. With mine up front, it gets plenty of air through it and my oil pressure never drops below 40 psi even with the engine at 212º.
Jake Voelckers

This thread comes up at least once a year, so I will try to be brief.

If you don't have a temp gauge for your oil you do not know whether you need a cooler or not.

Your oil temp should be 190-210' for best engine efficency. Ideally, you should not let oil temps exceed 240'.

If you do need an oil cooler, I suggest a Mocal take off with a built in thermostat so you will not cool oil to the point that it is hard on the engine, such as winter temperatures. The temp controlled take off also aids in getting oil up to temperature faster, much like the water thermostat does for the water.

My observation over the last few years of driving is that the oi temp is usually 10-15 degrees warmer than the water temp, so if your engine water is 180-195, you probably don't need an oil cooler.
jim Stuart

Unless you intend to flog the motor to death you really don't need a cooler.
I put my oil cooler on top of the radiator tray, where I could see it because the only reason why I fitted one was
a-I had bought a new one for the old 1800 4 pot and it was sitting on the shelf (cost nothing) and
B-I like the look of them.
I was also little nervious about clearance/running it into a parking curbe.
If you are going to fit one underneathe then I suggest that you also place your oil filter down low under the headlight, or somewhere similiar. The advantages of this is that it makes changeing the filter easy and mess free and ensures on startup that you don't have empty oil lines to fill.

PS- I like your MGC style radiator filler Jake,

Jim Stuart is correct.

If you think you need an oil cooler you would be well advised to fit an oil temperature gauge first.

If that indicates that an oil cooler is going to be beneficial I would suggest that an oil thermostat is, at least, sensible, if not essential.
Nigel Steward

As a matter of interest, the MG RV8 didn't get an oil cooler.

Mike Howlett

I'm gonna agree that an oil cooler isn't necessary. The way I analyze the situation is as follows.

With today's modern oils you aren'tlikely to get any oil breakdown problems with a normal engine anyway. This was one of the benefits of the cooler, to prevent this. A quality oil is very tough these days. I agree that it wouldn't hurt to have a cooler it but is it an asset?

The expense verses the results wouldn't be comparable. As mentioned before these engines run up to 195 or more degrees. To try and cool the oil off and return it at this engine temperature would seem futile.

The rate of flow with oil through standard cooler lines is a lot less then most people realize. Even at that, bigger lines could be better or worse because the slow moving oil could pick up or dissipate heat. In the engine the resistance's and small orifices at the bearing surfaces and narrow galleries on the output (pressure) side of the pump will prevent a large flowing capacity anyway. In effect there will be slow moving oil at the input side of the pump.

As the cooled oil entered the engine it probably wouldn't affectively produce any real cooling benefits. Remember we are talking about 195 or more degrees. This is because the length of the return hose from the cooler would absorb a quantity of heat from the hot engine compartment, after it had been cooled, from the radiator and the residual heat from exhaust manifolds. Any V8 owner knows that getting the heat out of the engine compartment can be a major undertaking with V8 installations. The capacity of the oil sump would probably be large enough and the residual oil in the pan and on the crankshaft would be hot enough that the cool oil would be absorbed in without much change and even less on its way back through the engine. You may at best cool the crank a little by splash. If you had splash guards then this would not be a benefit either. The coolant temperature of 195 degrees in the engine would regulate the temperature of the distributed oil throughout the engine anyway.The total effective result would be minimal.

This might be changed by using a larger flowing pump,mesh covered insulated hose, a good sized oil cooler with a 165 degree thermostat. If it's fuel injected then that brings on a whole set of other problems.

Dann BCC
Dann Wade

That was a very interesting and informative thread.

Nice to know I can dispense with the cooler and fit one later if needed.

Thanks everyone.

Thanks everyone for the information

GLG Lavis

A slight hobby-horse of mine - (no commercial interest of course).

If you are not fitting an oil cooler you will, presumably, fit an oil temperature gauge.

A great add-on would be an Accusump, which you could use to pre-oil the engine before using the starter motor, and could also use to drop cool oil into the sump in the case of the oil temperature rising to levels with which you are uncomfortable.

Add these benefits to automatic surge protection, and protection against low oil pressure from any other cause.... well worth considering:-
Nigel Steward

Nigel, you can't use the Accusump to cool the oil in the sump.

You do use it as a pre-oiler, normally switched on with the ignition.

But you can't just keep it in reserve so you can dump a couple of quarts into the sump if you think it needs cooling, or you will be running 2 quarts too high (or conversely two quarts low until you do the dump). That isn't what they are meant for.

They are meant for two things only - to pre-oil before starting the engine, and to prevent oil starvation in corners.
Bill Spohn

You guys should look for other things to woory about! I have a 4.9 with 12-1 comp., isky 280 cam, ported 300 heads, 300 crank & alu flywheel backed up with a T56 6 speed trans. with over 100,000 miles on it with NO OIL COLLER!!!! 13 sec. 1/4 mile & I have a trailer hitch on it & I will pull a traler that is 2.000 lbs. I have a 4.2 with F/I, A.C. & a hitch on her & 240,000 miles on her in 10 years with NO OIL COOLER!!!! ALL THE CARS I HAVE BUILT HAVE NO OIL COOLER!!!!! I talked with Phill Backer & D&D fab. Dan & thay ALL SAID NO WAY would thay put a oil coller on a V-8 B. My first V-8 G.T. has over 350,000 miles on her with a 3500 rover & she pulled a 3,000 lbs trailer ever weekend to a british swap meet. N.H. to Fla. to K.C. to the windy city & never a oil cooler!
Glenn Towery


IMHO you could be wrong; although the whole issue may be somewhat academic if you agree with Glen Towery (whom I respect).

In theory you dump the contents of the Accusump into the system. The additional oil mixes with the oil already in circulation, lowering the temperature.

Then, provided oil pressure is adequate, the Accusump is recharged with oil from the sump.

The issue will be is the oil which was originally in the Accusump cooler than the oil in the sump. My belief is that under normal circumstances Yes; but if you are repeating the dump/recharge cycle then this may not be so.

In the end we must make our own decisions. I have owned my “factory” B GTV8 sine new in August 1974. It’s been fitted with an oil cooler from day one, and I am happy with the outcome.
Nigel Steward

Way back in the days before the internet I had a '66 B roadster. It had an oil cooler in the standard place and I moved underneath, behind the font valance, so as to make room for an electric fine I had got from a scrap Renault 16. To make the hoses reach I put the long hose on the short side and lengthend the short hose by cutting it and putting in a length of 15mm OD copper central heating pipe.

I wish the information above had been available to me then as this modification let me down on more than one occation.

Now I sprint my '74 CD roadster in the standard class of the MGCC speed championship. I am always looking for legal, low cost ways of lightening the car. I think I have just found one. Hope I can find one of those pipes that fits in place of the cooler hoses.

David Witham

If the visc of oil is correct at 100c, then below this wastes energy and above the oil becomes thinner and may not prevent metal to metal contact.

A lot of time may be spent in the warm up phase and a thin oil at low temp should be used which thins less at high temp. A synthetic oil is the closest fit to these requirements and can withstand higher temps than mineral and cools 10% better. A cooler should be fitted at temps over say 110c to maintain visc and by using a lower visc synth additional bhp may be gained.

There's a lot to be said for Glen's approach. I've never had an oil cooler on my car either, and I've run some pretty high output engines. In American cars an oil cooler is not considered necessary under normal circumstances, and that is assuming your cooling system is adequate. If you run the stock V-8 radiator or something very similar though I believe I'd retain the oil cooler.

Jim Blackwood

On my 1800 B, I have a thermostat in the cooler circuit. I have checked the temp of the cooler with my hand after driving at all times of the year, and it very rarely comes into circuit. The thermostat opens at 85 Celcius, so the oil in the pipe rarely reaches that temperature. Obviously a V8 will make more heat, but you can go a lot higher than 85 C before there's any trouble.

I know Scotland is not a hot country and it could be different if you live in Arizona. What bothers me is that the oil in the cooler is now ancient - what effect will it have if and when the stat finally opens?

Mike Howlett


With mineral based oils waxes will form when exposed to the cold. Would not be a good place to store oil.

BMW rule of thumb 130c for mineral 150c for synth although sump temps at bearings oil will be approx 150c.

Even in Arizona Ford tend to spec a 5W20 wheras Euro oil spec tend to require HTHS of 3.5



Nigel said: "In theory you dump the contents of the Accusump into the system. The additional oil mixes with the oil already in circulation, lowering the temperature.

Then, provided oil pressure is adequate, the Accusump is recharged with oil from the sump."

Well Nigel, if you are driving the car that means that the oil gallery is up to full pressure - which means that if you open the valve on the Accusump, nothing will come out. It doesn't come out (against full pressure), wander around and then go back into the cylinder after cooling the oil in the sump.

If you stop the engine so that the pressure in the main gallery drops and then open the valve, of course it will go into the gallery and thence to the sump - but that was why I raised the question of do you start with 2 quarts too little or end up with 2 quarts too much in the sump?

The only correct way to use the Accusump is to trigger it immediately before firing the engine and turn it off when the engine stops and it is still 'charged'. If you switch the ignition on and are not able to start immediately, you will end up with a sump full of extra oil (which will get stuffed back into the cylinder after it DOES fire up). If you forget to turn off the tap (some are not solenoid operated) when you stop the engine, all the oil will also go into the sump - which is why I prefer my Accusumps hooked into the ignition, but with an override switch.
Bill Spohn

This thread was discussed between 19/02/2006 and 21/02/2006

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