[Bhozar]

I keep reading how heat is the enemy of power and longevity, hence the need to aftermarket intercoolers, but what about the oil temperature?

I know many cars have oil coolers, but there doesn’t seem to be much discussion about them on this forum for our MINI’s.

Are they worth fitting? Currently my car is used every day for commuting, but is driven hard on the weekend and on tracks when I can. I have read about the oil coolers cooling the oil too much when they aren’t driven hard all the time. It is 230bhp+ and I intent to eek a bit more power from it in the future, probably going up to a 260 GTT conversion.

We have many tuners on this forum; how many of them actually have an oil cooler fitted, and what do they think of them?

Does it need to have a thermostat fitted for the oil cooler? Why does it need one fitted?

Is there anything else I should know about oil coolers?

[Richard Crofts]

TBH honest an oil cooler doesn't add any power really (unless there a minute amount of power loss caused by over warm engine bleeding extra warmth into the bay and causing intake and charger temps to rise...but I can't see that this is significant enough to be a worry??!).

The only real reason for them is to maintain good oil operating tempretures on highly tuned cars. The more you tune a car the hotter things will run and therefore the thinner the oil can get (if the oil thins too much it won't do its job) as it runs like water and doesn't coat the internals properly and can be burned off easily causing excessive wear.

Having had a very highly tuned Hillman Imp I fitted an oil cooler and various other oil related items to ensure the cars internals were kept in fine fettle. Theres no power increase but wear is in theory reduced due to the oil being kept at an optimum effective tempreture. Also the nessesity on the Imp was also that engine temps get high in that car as the engine is in the rear and has quite poor airflow...so having some extra cooling capacity on the oil system as well as the normal system is helpful.

The cooler won't really 'over cool' the oil once the car is up and running warm etc unless its stupidly big for the system and you pootle everywhere (I'm guessing about this I've never had this problem myself). The problem I had was that at start-up it took longer for the oil temp to rise to optimum temp levels due to the extra cooling provided by the oil cooler.

I'm sure that clever people would come up with some sort of thermostat system to allow the oil to use the normal system route when cold and open up to use the cooler route when hot but I was not that clever or patient to work something out.

On the Imp we had all sorts of things like oil retention channels cut into the block to help the very hot and therefore thin oil to be retained as much as possible and reduce wear caused by thin oil running off internal surfaces too fast and being burned off too easily...but that all involves some quite intricut machining work and on a car as sturdy as the MINi (and low reving...7-8k depending on map compared to my Imp which was 13k redline) its propbably not worth it for a road/track day car.

An oil cooler (although doesn't the MINI have one anyhow???! So maybe I mean a bigger oil cooler rather than adding one) is probably not a terible idea for a track car or highly tuned car...but TBH I don't think you'd see much from it being added really.

I'm no expert but from having done work on other (older) cars I'd say that on the MINI its probably one of the last things i'd bother fiddling with.

[Bhozar]

Thanks for the answer Crofty. I was thinking about it in regards to longevity and reliability.

I also never "pootle" anywhere really. Thats for people who wear skin tight baby blue jumpers

My other concern is that the oil doesnt drain out of the cooler when its time to change the oil. Only photo I have found of a MCS with an oil cooler has it at the front of the car on top of the AC rad.

Hillman Imp eh? I used to have a Hillman Avenger 1.6. Sold it for £73.50 to a gypsy.

[Richard Crofts]

Strange my Dad bought his (which became mine) for about £73.50 from a gypsy !

Mine was less than 1 litre even when it was bored out...but the alloy block allowed it too rev like a flippin trooper...I kid you not when i say that it would be still accelerating at 11k and would top out at about 13k. You ain't heard nothing till youv'e heard a car doing 10-12k on a dog box with no silencer fitted to the large bore custom pipe! That thing was very scary.

Not sure on the location of an oil cooler for the MINI, but it seems strange that any modern car especially a higher performance one does not have some form of oil cooler fitted as standard...I mean even Rover fitted a small oil cooler to the A series 1.3 N/A RSP Coopers in the early 90's! And they were doing 63bhp not 163bhp +

[MINIMANIAUK]

Simply yes an oil cooler is needed on tuned cooper s, on a stock car no, not required unless track day running. (bear in mind the jcw has no cooler but only220bhp)
The standard engine is strong and reliable as standard,but when tuned there are issues to be addressed, The JCW/GP cars had a lot of testing and development work done by I believe Ricardo,not JCW , under the control of BMW who also contracted out other development work, and they gathered a lot of info before offering the works option and tailored it to suit the requirements and limits that they found.
to increase the output is easy, to also cater for the weaker areas is what is required for long term reliability. There is also the cost implication from the manufacturers and that is the overriding factor in how the JCW is as it is and the differences with the JCM items

We have fitted a number of coolers,and on return for servicing the oil removed was beautiful no signs whatever of being overheated,time will be the test , as always

[Richard Crofts]

Logevity wise its a useful mod on a tuned car. Especially if what minimania appears to be saying is true (that the S doesn't have one as standard :shock: )

I honestly assumed that they would have fitted something, especially on the JCW but if they havent then I'd have thought anything running significantly higher than JCW 210-220 should consider it as a possible mod to help cope with oil thinning on track days etc. If you go to 260+ Bhozar then it might be well worth the few quid extra to get a cooler fitted, given theres nothing there at all as standard...I am really quite shocked by that, seems like such a cheap but pretty essential mod in a high performance car?! Maybe the more modern materials and build processes mean that modern engines don't suffer as much from major oil heating issues when tuned as the older style engines I used to work on, so oil coolers are not needed as much as they were when tuning older cars.

Cheers for that peice of info minimania...I just still can't fully believe that they don't fit one...Like i said the 63hp RSP Coopers had them yet something running 163hp and a big top mounted charger doesn't ...How odd?!

[Bhozar]

Thanks for the replies. I have been doing a bit more research on the subject and found some more information.

One person setup the CVT oil coiler to do the engine oil, but to save money didnt fit a thermostat. So during normal road driving would stick some card in the front of the engine bay to stop the oil from being cooled so much. you can read about it and see pics here: MINI engine oil cooler for heavy track use - BMWCCA Pugetsound Chapter BB

Webb Motorsport have a section in their FAQ about oil coolers in relation to pully sizes. They say they dont use larger than a 15% pully due to heat issues.

Quote:

Also related to reliability, but much less of an issue, is the water pump speed. We didn't think this was an issue at first, until we started monitoring oil temp as well as coolant temp. On the track, we noticed elevated oil temps that we didn't see with 15% pulleys. It took a bit to figure this one out, but if the pump is cavitating, it will show first on oil temp. The reason behind it has to do with the volume of water and its movement through the entire head versus through the oil cooler. On the MINI, the oil is cooled with a water-oil exchanger. The water volume is great enough in the entire system that a small flow change does not effect coolant temp at the coolant temp sensor, but with the small volume in the oil cooler, the oil is not cooled as efficiently if the flow is decreased even a small amount, resulting in higher oil temps. This seems only to be an issue with the 19% reduction pulley at sustained high RPM.

Source: Webb Motorsports | FAQ

[MINIMANIAUK]

We also use the CVT oil cooler but with temp control,as it fits perfectly and larger than the mocal ones,similar take off plate but with aeroquip lines, the webb motor sport review is also accurate ,but does not fully take on board the oil/water cooling interface design -its more for heating than cooling, and the full effect of higher boost caused heat on the engine.
there are issues which I dont want to go into and may seem alarmist to some,but they are real and need to be addressed. the water and oil cooling needs to be improved on the higher power conversions its not an expensive exercise and safeguards the £1000s spent on tuning
yes its odd that there is no extra cooling on the jcw/gp ,then again its odd the manifold is stock,the exhaust not stainless,the airbox rpm opened,the cam /valves stock ,the head 1/2 ported,the crimped section in the exhaust, all would have improved the car but I guess cost /proit was the goal

[Bhozar]

Quote: Originally Posted by MINIMANIAUK (original)

We also use the CVT oil cooler but with temp control,as it fits perfectly and larger than the mocal ones,similar take off plate but with aeroquip lines, the webb motor sport review is also accurate ,but does not fully take on board the oil/water cooling interface design -its more for heating than cooling, and the full effect of higher boost caused heat on the engine.
there are issues which I dont want to go into and may seem alarmist to some,but they are real and need to be addressed. the water and oil cooling needs to be improved on the higher power conversions its not an expensive exercise and safeguards the £1000s spent on tuning
yes its odd that there is no extra cooling on the jcw/gp ,then again its odd the manifold is stock,the exhaust not stainless,the airbox rpm opened,the cam /valves stock ,the head 1/2 ported,the crimped section in the exhaust, all would have improved the car but I guess cost /proit was the goal

I must be looking at the wrong site, as the only oil cooler I can find on minimaniauk.com doesnt seem to be the CVT cooler or have a any thermostat or temp control of any kind with it. Could you direct me to the product you are talking about please?

I would be interested in reading the "alarmist" issues. I tend to be cautious on modifying and I try to get the best I can so I dont have any issues or breakdowns. Roland had weeks of me pestering him with questions before I decided to go get some stuff done. I also need the car to be as reliable as stock as I use it for my daily commute.

It seems like the person concerned about oil temperature of tuned MINI's on MINI2.com is you, so I would like to hear more. I have tried researching this in the past on the site, to find info lacking, so I am hoping this will turn out to be a useful thread for me, and others, in the future.

[Berthil]

I have seen the CVT cooler fitted as an oil cooler, fits very well.

I have oil cooler with thermostat as my MCS is tuned and I do trackdays. This cooler results in a 15 to 20 degrees lower oil temperature. It's a must when you do track days or long high speed Autobahn drives with a tuned MCS. Don't save money on a thermostat, it's a must to let the oil get on best operating temp quick. The KTM heat exchanger, which is switched for a plate to re-route oil to a cooler, is there to use the cooling water to heat up the oil quickly on cold starts as the engine cooling water heats up much quicker than the oil.

This is my setup but I had to make some room behind the aero grill for it.
Nevertheless I still managed to mount driving lights and the badgeholder

[Ant FR]

i thought the MCS had an oil cooler on it standard ....???? or am i getting confused with the new shape Mini Turbo

[Richard Crofts]

Had a look at my 52 plate S and there appears to be no oil cooler on that...shocking really IMO. Checked out the Haynes manual while sitting in traffic last night too and theres no mention of a cooler in there either.

R

[Berthil]

As I wrote, the R53 MCS has a heat exchanger (manufactured by KTM) which uses the cooling water to warm up the oil more quickly at cold starts.

This is mistakingly referred to as the standard oil cooler sometimes.

[MINIMANIAUK]

Berthil has it spot on,and better still catered for it, whenever you tune an engine it has a an impact on longevity , if you cater for it fine, if you do not it will cost you in the long run,I have posted a couple of times about things like increased maintenance,mostly ignored as it is a boring subject!!!
what I mention on here is because its what I see day to day, and not in the area of the TLC or dealers or standard cars.
as an example how many on here are running smaller pulleys? OK now how many have replaced the oil in the supercharger?---mmmmm ----none!
Eaton life the oil at 100000 miles ON the stock charger,with reduced pulleys beyond 15% the heating increases rapidly the oil degrades quicker,if you look inside a charger you often see oil residue, on pulleyied (I just made that word up) chargers it is very black and very smelly , -the result charger bearing failure, at best a new charger at worst a new engine
Cost of oil £8
My reccomendation is to not exceed 40000 miles ,pull off charger ,clean and re-oil (synthetic supercharger oil) track cars more often
keeping the website updated is very difficult with so many products and developments and very time consuming , we have far more items available than listed,so it can pay to e-mail if you need info or used parts etc,
sorry yet another boring post

[Bhozar]

Quote: Originally Posted by MINIMANIAUK (original)

sorry yet another boring post

Not a boring post at all. Its the sort of info myself and others would want to know.

Could you PM me some details about the oil cooler setup you can do thats not on the site please? Or, post it here so everyone can see it. Does it have a thermostat?

From what I have been reading its a must as there would no longer be the oil heater that the stock engine has and when the oil is cold you want it to heat up quicker, the last thing you would want happening is additional cooling at that time.

I intend to keep my car as my main transport for a few years before it becomes just a weekend plaything, so I want to safeguard the engines future. Its done 32k miles now, and 5k since it had the GTT pully stuff done.

Interesting that you brought up the SC oil. When I have been searching for oil coolers I read some info saying the same sort of thing. One guy had hit 100k and changed his oil to find it still pretty clean, but said its better to find clean oil when you change it that to blow something up.

[robbo mcs]

Quote: Originally Posted by MINIMANIAUK (original)

Berthil has it spot on,and better still catered for it, whenever you tune an engine it has a an impact on longevity , if you cater for it fine, if you do not it will cost you in the long run,I have posted a couple of times about things like increased maintenance,mostly ignored as it is a boring subject!!!
what I mention on here is because its what I see day to day, and not in the area of the TLC or dealers or standard cars.

sorry yet another boring post

Hi,

This becomes especially true when the car becomes a track or competitive car only, and is not driven on the road at all. Not driving the car on the road robs you of the opportunity to notice little noises, misbehaviours etc, as you often don't notice them as easily in competition due to the noise and violent environment

My car has now done around 35,000kms of competitive driving ie race track or closed road tarmac rallies. It is a question of being proactive rather than waiting for things to go wrong. Everything on the car needs regular inspection, and replacement of parts. If in doubt about a part , I opt to replace the part, and keep the old part as an emergency spare There are also many parts than I get replaced on a routine basis, regardless of any signs of wear and tear.

This all costs big $$$ However, if I am doing a rally, where the total entry fee, transport, accomodation, support crew budget etc is $AUS12-15k, it would be painful to see it fail due to a $100 part that wasn't serviced or replaced

The only problem is that with more experience, the number and variety of parts that need watching and routinely servicing / replacing keeps growing

For people doing major mods, and using the car on track days etc, regular routine maintenence should be part of the budget The absolute minimum should be for the car to be on a hoist after every 2-3 events for a look over and spanner check. If you have a good mechanic, doing this will save you lots of money and angst in the long run

Cheers

Robbo

[fozworth]

Hi guys (adam its jamie from bristol)My cooper s is running with various mods and has 58k on the clock.the origonal conversion is a BBR 220 phase 1 conversion.but now has many other mods including ,piper cam ,ported head ,gtt header and exhuast,light flywheel,GRS intercooler,Alta cai kit,and so on.and mth soft ware.Firstly does anyone know what size pully BBR stick on there fase 1 conversions.and secondly do i need a oil cooler and if so how much does it cost to buy and have one fitted.cheers jamie.

[MINIMANIAUK]

Hi Jamie, the oil cooler requirement is very much down to how its driven and not is spec ,
a) If you are driving miss daisy -no its not needed
b )If you drive it like you stole it- yes

Thing is most people who have a tuned car fall into the b) category
In your case you are running nitrous so at high boost you have a very large cooling effect
provided the bottle is full, when you run out of nitrous just offer miss Daisy a lift

[fozworth]

Thanks Adam,advice n info taken.Will still come and visit after xmas to spend me money on the short shifter fitment then,so as usual the money still goes,but thanks for that .and see you soon.Oh might see you before hand if i pic those leeds up if not i'll get them sent happy xmas buddy!

[Bhozar]

MINIMANIAUK, could you PM me some details about the oil cooler setup you can do thats not on the site please? Or, post it here so everyone can see it. Does it have a thermostat?