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MG MGB Technical - Oil Cooler Hoses

I am taking the engine out of my ´63 MGB to change the gearbox, and want to renew the oil hoses at the same time, just as a precaution.

The cooler hoses I have now are marked Mocal, from Moss, and dated 2004. I have a couple of spare hoses lying around. They have never been used, have been kept in a dark and cool place, and look and feel just like new. But they are dated 2007.

The spare hoses are not marked Mocal or Moss, but have the same specification printed on the rubber as the Moss ones.

Should I use them, or is it safer to buy new ones?

Tore
Tore

personally I wouldn't refit an oil cooler, there was never a need for an oil cooler in the first place unless a lot of heavy towing or race track use of the car

most of the year in Britain the oil cooler would over cool the oil so in Norway I'd guess it would be the same or more so

if an oil cooler is used it needs an oil thermostat also fitted to prevent the over cooling

to answer your question -
much rubber recently has been crap including braided covered oil cooler hoses but if they've survived since 2007 I'd guess they have perhaps proved they're not the really rubbish ones

the main thing with the oil cooler hoses is that they're secured with the necessary brackets and grommets are used where required as they will empty out the oil quickly if they get scuffed through

if you must retain the oil cooler then do fit an oil thermostat if you've not already got one fitted

you're supposed to blank off the oil cooler during cooler weather and that could even be some days during the summer

other cars that had the same engine and done heavier work didn't have oil coolers fitted plus oils are much better now than 30-50 years ago
Nigel Atkins

Tore,

Originally the oil cooler was an "extra" which bears out Nigel's point concerning need. If you decide to keep the cooler (do check it carefully because they can easily get bunged up with road muck) and if your hoses show any signs of deterioration, I would take your new hoses to an hose specialist and ask them to fit their best quality hose to the fittings you give them. That way you can be sure they will last most of a lifetime. I don't know what the specialists are called in Norway but here, the American firm Hyphose has the appropriate selection of armoured pressure hose.

Roger
Roger W

The reason the oil cooler was fitted was because the sump is largely shielded by the front crossmember and the oil can overheat under some circumstances. Other cars either produced less power or the sump cooled the oil adequately.

A thermostat is worth fitting.

Be careful in having heavy duty oil cooler hoses made up - some of the shielded hoses are too stiff and vibration can be transmitted to the cooler which can fracture the fittings from the neck or the base from the cooler.
Chris at Octarine Services

yet I've seen that Californian cars didn't have an oil cooler and it's hotter there than here or Norway

I know it's a different model and different engine but sump cooling is often mentioned for fitting oil coolers to the the (Triumph engined) midget 1500 yet oil cooler were not fit to them from factory or offered as an optional extra and many original owners ran them successfully in normal every day use for many tens of thousands of miles without the need for an oil cooler
Nigel Atkins

The sump on a Midget is even more shielded that the B, being entirely above the chassis rails.

I've used a company called Pirtek to shorten an MGB oil cooler hose to fit a Sprite.

http://www.pirtek.co.uk/

They even list brake hoses for MGs

http://www.pirtek.co.uk/pirtek-products/pirtek-automotive.aspx
Dave O'Neill2

>>The sump on a Midget is even more shielded that the B, being entirely above the chassis rails.<<
which given the facts that oil coolers were not factory fitted or offered as optional extras and that original owners didn't need them suggests oil coolers weren't need on the Midget 1500 when the cars were current at least

places (shops/warehouses) that deal with farms might offer hydraulic hoses and possibly making them up from fittings

from what I've heard some of the usual classic car parts suppliers oil cooler pipe kits aren't a good fit unless that has changed now
Nigel Atkins

I'd heard the cooler was fitted as standard to counteract owner complaints of low oil pressure (I wonder why oil pressure gauges are rarely fitted these days ...). Certainly on the V8 I can have 30 psi in summer when I first start idling after running in clear air, but stuck in traffic that drops and drops towards 15, i.e. when there is no oil cooling.

Can you over-cool oil? I agree that under many circumstances there will be no need for additional cooling, but does it hurt? I think we'd know by now if it did.

None of which answers the original question of whether it is better to buy new hoses or refit old. Mine are probably original to the cars, i.e. 40 years, and I can't imagine replacing them until I have to. New stuff these days can be poor quality, and if I did replace them I wouldn't get the braided type.
Paul Hunt

Yes Paul you can over cool oil to the point that the condensates from the combustion process that find their way into the sump are not driven off and the oil becomes acidic.

Hence the suggestion of fitting a thermostat.

The 1500 engine is even more in need of a cooler - it is a fragile engine at best and for this reason I no longer rebuild them.

Generally I would say you need about 10 psi for every 1000 rpm, but the V8 is a high volume / low pressure system and I have no problem with running it at 40 psi max.

As to whether to use OE hoses in store then - I would keep the ones on the car till they really need changing - then there will be a good set in reserve!
Chris at Octarine Services

As Chris says, any doubts on a B or Midget, concerning oil temp can be negated by fitting an oil stat. The V8 is a different case, unlikely to be over-cooled, indeed the health of the bottom end is dependent on staying below 72deg, the oil plays a major part in that. Conversely consistent oil pressures above 60psi can cause serious wear to the skew gear driving the oil pump.
As for anything new and rubber…………………beware!!! If the hoses look Ok with no cracking or unusual stiffness, stick with OE.
Allan Reeling

I can understand low oil temperature in the sump in cold weather, less so as it passes through an engine fully up to temperature. That's why short journeys in cold weather are bad.
Paul Hunt

"The V8 is a different case, unlikely to be over-cooled, indeed the health of the bottom end is dependent on staying below 72deg, the oil plays a major part in that."

And yet the RV8, designed and built in the nineties with the 3.9 litre, 180 hp engine, has no oil cooler. I have the same engine in my MGB GT V8 conversion and believe me that engine makes a LOT of heat. I also have no oil cooler on my car and even on the hottest summer day I have no oil pressure problems, running at 30 - 40 psi all day long, and never going below 20 psi when stopped in traffic with the rad fans whirring away.

When I had an 1800 MGB I fitted an oil thermostat which opened at 85 degrees C and let the oil through to the cooler. As an interested owner, I would often pop the bonnet after a run and feel the hoses. They were hardly ever warm, meaning that the oil had never reached 85. That was true even in summer, the stat only opening if I got seriously stuck in traffic in warm weather.

The MGF has an oil temp gauge and the handbook tells you that it should run at or above 95 celcius, and not to rev the engine until the oil is hot. I bet the oil in many MGBs never gets close to 95 C. I'm no expert but I reckon 72 C is too low and will have the oil contaminated by condensed water and other impurities.
Mike Howlett

Mike,
You're right up to a point. My memory is failing me, the temp is 80!
Bottom end and bearing cap temps climbing above that lead to increased fretting between the two. This is a problem caused by different coefficient of expansion of Aluminium and the cast iron used for the caps. This cause of possible engine scrappage was solved on the later interim and cross bolted units which used aluminium caps.

Also keeping parts to a temp by circulating oil (or water) doesn't mean that the liquid and the part are at the same temp, the coolant is actually taking excess heat away, hence finishes up hotter.

The RV8 was given a bigger and more efficient rad therefore oil cooling was not needed to supplement engine cooling.

If your 3.9 in a GT runs at those pressures on hot days in traffic, either your gauge is over reading or someone has beefed up the oil pressure relief spring. OR you've managed to fit a crank driven pump!! 40psi on a hot day must mean in excess of 60psi on warm up on a cold day putting a lot of strain on the skew gear driving the dizzy and the oil pump. I've seen the cam skew stripped due to the oil pump being fitted with a stronger spring.

1800 engines were well known for not needing an oil cooler except in VERY hot climates, it was probably added for image and appeal value.

The MGF advice is related to their well known head gasket problem. The stretch bolt clamping force is at it's maximum when everything is fully hot and therefore fully expanded.
Allan Reeling

Don't be daft - of course my V8 doesn't run at 60 psi when cold. It never goes above 40, even on first start-up. But even when hot, at any revs above idling the pressure is over 30. There is nothing special about my engine at all - all standard components, apart from a mildly tuned camshaft and heads. Its a 1991 EFi engine from a Range Rover. I do have an uprated radiator from Clive Wheatley, and if anything the engine is a little over-cooled in the winter. As long as the car keeps moving, the temp gauge rarely gets above 170 F, and I think its pretty accurate as it was new from Speedy Cables not too long ago.
Mike Howlett

Tore-
Enhanced-performance engines produce more power by creating more heat in order to expand the atmosphere inside of their cylinders in order to force the pistons, their connecting rods, and the crankshaft to do more work. This in turn places increased pressure upon their bearing surfaces inside of the engine. This increased heat and pressure places additional strain upon the lubricating oil, shortening its useful lifespan. In addition, the sump is largely shielded by the front crossmember from cooling airflow and so the oil can overheat under some circumstances. While the radiator performs the function of cooling both the cylinder head and the cylinders, it should be noted that it is actually the oil that cools the internal parts of the engine. While mineral-based oils are fairly efficient at absorbing and transferring heat, the more heat-resistant synthetic oils are relatively inefficient at this task.

In order to assist in this function, as well as to help protect the lubricating qualities of the oil from breakdown, an oil cooler was fitted to all MGBs except during the 1975 through 1980 production years when power output was chopped in an effort to meet emissions regulations. The correct running temperature of the oil is perhaps even more important than coolant temperatures. North American market cars had a 13-row cooler, and this should be considered to be the absolute minimum for an enhanced-performance engine. If your car has one, be sure that it is hot tanked along with the other components and thoroughly cleaned out before reinstalling it. The importance of giving it a thorough cleaning cannot be overestimated as it will contain sediment that will ruin your new engine. If you are replacing it or installing one for the first time, use one that has at least 16 rows and install a 200 degrees Fahrenheit (93.3 degrees Celsius) thermostatic bypass valve as overcooled oil can rob power and lead to accelerated wear. Because overcooled oil is thicker than it would be at normal operating temperatures, the piston rings will tend to “hydroplane” over the oil and, on the upward stroke of the piston, scrape it into the combustion chamber where it will be burned, leading to carbon deposits and an increased risk of preignition. Thermostatic bypass valves have a dual function in which the flow of oil is either channeled directly to the oil filter when the oil temperature is below 200 degrees Fahrenheit (93.3 degrees Celsius), or is channeled directly to the oil cooler when the oil temperature is above 200 degrees Fahrenheit (93.3 degrees Celsius). An excellent thermostatic bypass valve with ½” NPT threads is available from Perma-Cool (Perma-Cool Part # 1070). Perma-Cool has a website that can be found at http://www.perma-cool.com . Personally, I use Mobil 1 in all of my cars and I agree that it resists molecular shear better than the petroleum-based oils. However, it is always best to think in the long-term. Just because modern oils can withstand heat without breaking down as rapidly as they did in the past does not mean that the consequences of the heat can be thus ignored. As motor oil degrades with use, it becomes less thermally efficient and thus cannot remove heat as well as it did when it was new. An oil cooler helps to get rid of the excess heat that can destroy the additives that were added by the refiner in order to help protect the engine. Engines wear more slowly and thus last longer when their operating tolerances stay within engineering specifications, even when the oil is of the best lubricating quality. Thus we see that the crucial deciding factor behind installing an oil cooler is the fact that it is the oil that carries away the heat from the moving parts. This being the case, a thermostatically-controlled oil cooler can be considered to be a wise move for a car that is going to be kept and run for many years.
Stephen Strange

yeah

but for a novice home mechanic it must be said
thermostat controlled cooler is the only correct answer to this
when fitting the thermostat we need to fully understand oil flow direction in the cooler/hoses and understand where oil is being diverted
you really need a full grasp of what is going on before mods are carried out willy
William Revit

Thanks, everybody! Lots of interesting comments here. I´m not sure if any of you actually commented on the age of the oil cooler hoses, if it is considered to be safe to use new old stock hoses from 2007 or better to buy new ones.

Has there been any quality problems with these hoses lately?

I don´t think I actually need an oil cooler in Norway, and I often cover it with tape in spring and autumn. Fortunately I use the MGB mainly for longer trips, where the engine gets up to normal operating temperature and stays there for quite a while.

Tore


Tore,

oilhoses last very long if not damagded from touching and rubbing sue to wrong mounting.

I'm using Aeriquip hoses, they are available with special push-on connections so you can cut them to any length.
Those are sold at shops for racing goodies and are much cheaper than thoese from MG dealers.
(40000 km Alpine Montain experience in mga twin cam)
Thermostat is a must! (Mocal)

Have Fun!

Siggi
Siggi

you missed it then in my first post -

>>to answer your question -
much rubber recently has been crap including braided covered oil cooler hoses but if they've survived since 2007 I'd guess they have perhaps proved they're not the really rubbish ones

the main thing with the oil cooler hoses is that they're secured with the necessary brackets and grommets where required as they will empty out the oil quickly if they get scuffed through

if you must retain the oil cooler then do fit an oil thermostat if you've not already got one fitted

you're supposed to blank off the oil cooler during cooler weather and that could even be some days during the summer<<
Nigel Atkins

This thread was discussed between 06/03/2014 and 11/03/2014

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