18 replies to this topic

[scotty_18]

Hi all,

I hear/read a few days back that if you were to fit a sump guard, you would have to install an oil cooler too..

Is this true?

[#shropshire]

thats the most stupid'st thing ive ever heard who told you that , i might be wrong but oil is for the car all the sump guard does is err protect the sump lol

[mk1leg]

Not nessaserly.....an oil cooler is good for highly tuned motors or race track cars..........it does not mean you can not fit one, but you would need a better oil pump in to cope with the extra distance the oil has to traver round the engine......the early cooper S engines from 1963-69 had then as std.........

[scotty_18]

Yeah thats what i thought! I can't remember where i heard it.. just thought i'd check

[maggies_minder]

i think its more due to the fact that the sump (which is responsible for the cooling of the oil via air flow) is blocked from said air flow by the sump guard.

it was cooperman who said you SHOULD fit an oil cooler when fitting a sump guard.


the guy is a mini legend and has forgotten more about minis than most of us know, i know whos word id trust.

Edited by maggies_minder, 17 July 2011 - 05:38 PM.

[DanNomNom]

thats the most stupid'st thing ive ever heard who told you that , i might be wrong but oil is for the car all the sump guard does is err protect the sump lol

It's not actually that stupid. A sump guard can reduce the airflow to the sump, which reduces the amount the oil is cooled, therefore an oil cooler may be required to bring oil temp down again.

[RayBoogs]

I'd Imagine it would have an effect on the cooling, the oil will cool in the sump, hence the fins, so blocking the sump may cause the oil to get hotter!

Not that stupid when you think about it.

[joel93]

the oil become very hot with no air flow hents the holes in sump gaurds

[mike.]

Ifr you fit a sump guard you block a lot of the ventilation around the sump. Since the sump is full of fins to help cool the oil on a mini, its a good idea to fit an oil cooler as well if you fit a sump guard.

This is especially true if its a trackday/rally/fast road car thats going to be driven hard. On a hot day, driving the car hard with a sump guard and no oil cooler its pretty likely you'll cook you oil.

[TopCatCustom]

thats the most stupid'st thing ive ever heard who told you that , i might be wrong but oil is for the car all the sump guard does is err protect the sump lol

Still the most stupid(ist) thing you ever heard?!

[maggies_minder]

thats the most stupid'st thing ive ever heard who told you that , i might be wrong but oil is for the car all the sump guard does is err protect the sump lol

Still the most stupid(ist) thing you ever heard?!

exactly what i thought, hopefully the cats got both his tongue and fingers, so we dont get anymore daft advice.

[Cooperman]

I did post on this in another thread very recently.
A sump guard will partially blank off the aluminium cooling fins on the sump which are there to act as a 'heat-sink' for the engine/gearbox oil. Yes, I know there are holes in the front of the guard, but they restrict the clean flow of cool air over the fins. The only reason for fitting a sump guard is to shield those same gearbox fins and the gearbox casing when driving hard over rough roads. If you drive hard the engine oil will run hotter and loss of oil cooling will exacerbate the situation. This was brought home to me when I fitted a sump guard on a 998 Cooper without a cooler. A 20 mile run up the M1 at about 75 mph saw the previously good (like 65 psi) oil pressure at cruising revs drop to 30 psi with the oil light then coming on at tickover.
If anone thinks it's stupid to deem an oil cooler necessary with a sump guard then fine, don't fit one. But don't complain about low oil pressure and high engine bearing wear when that happens. It's not my car on which the oil pressure will be too low.

[icklemini]

As above its suggested to fit an oil cooler... probably better to fit an oil cooler and the necessary thermostat... (cold oil isnt good either)

Yep over cooking the oil in the old days was a problem... quality of oils have got better though

Worth remembering that lots of modern stuff have engine undertray which kill any form of cooling under there.... some have oil coolers and some dont...

Edited by icklemini, 17 July 2011 - 06:49 PM.

[Cooperman]

Interestingly it was/is not a problem with cars which don't have shared engine and gearbox oil. That is why the heat-sink fins were fitted to the cast Mini sump in the first place. I have a Rover 214Si rally car with a huge full-length Rover-Sport aluminium sump guard and oil temperature is not an issue even with no oil cooler. It simply doesn't need one. However, the design of the Mini does mean that with a sump guard and no oil cooler the oil will get very hot which is not too good for engine or gearbox.

[icklemini]

yeah there is 'less oil' in a mini engine and box combo compared with anything else... (that usually has 5l of engine oil... + a couple more for the gearbox). Yeah some have oil cooleres... some have gearbox oil coolers... some have nothing...

The circuit racers get very warm even with an oil cooler and no sump guard... though different oils do yield different result..

Certainly no other A series had finned sumps (morris minors through to maestro vans!)... but then no other a series shared the oil with the box other than the mini/metro