Fitting an Oil Cooler

[Blade Runner]

My apologies to any hows read these queries under "Explanation of an Appollo Tank" but thought they may go unanswered under an old topic.

I am wanting to fit an oil cooler to my '99sl. In studying the plumbing it seams logical to me to fit the cooler inline with the appollo tank but i am unsure of the details needed eg: do i plumb it to the flow or return side of the appollo? where is the best place to mount the cooler? are the pipes best to come out the top of the cooler or the bottom?

Any answers or experiences would be appreciated.

Trevor

 

[MartinWoodham]

Trevor, 2p worth since no-one's answered yet...!

 

I've had an oil cooler sitting on a shelf for 2 years having gone through the thought process that you are. I ended up with the view that oil temps only get really high during a race, and that's such a short duration that it's not worth the bother.

 

IMHO there are a couple of things that count against cooler/ apollo combo:

 

If you plumb the cooler into the apollo input line, there will be (potentially) aerated oil going through the cooler, so it won't be efficient.

If you plumb the cooler into the bottom line, ie output, you have a restriction (depends on cooler and pipework location) between the apollo and the bearings. If cornering forces etc cause the sump pickup to be uncovered, the oil pump will lose efficiency as it sucks up air.....your bearings then depend on the head of oil in the apollo, plus any residual pump pressure (small, and vented to the cam cover via a restrictor), being able to maintain oil pressure when fed via the inevitable restriction of an oil cooler.

 

On balance the first is prob the lesser of two evils, I decided I'd watch oil temps and fit the cooler if I felt the need, and I never have.

 

Coolers generally seem to be fitted just behind/ just in front of the rad, low down, although the turbo-nutter swiss version had a cooler high up in front of the rad IIRC.

I would think low is good if you've plumbed into the apollo output since you'll lose all oil pressure under uncovered-pickup conditions I would think? Might get a bit of syphoning going on.

 

BTW my car runs without a water thermostat, so water temps are generally low, which probably helps. I wouldn't recommend this on a non-race car, the thing never warms up on the road!

 

 

 

Martin

Roadsports B with upgradeitis

 

 

[Steve Cragg]

Assuming you are talking about a laminova type cooler (ie. water cooled) rather than an air colled unit there are some good instructions on Roy Booth's site here under modifications.

 

Lots of people have a laminova fitted combined with an Apollo and it is a proven solution.

 

Steve

Superlight #63

[Mr Locust]

In simple terms, and ignoring the de-aeration issue, the pressure drop across the oil cooler is due to its resistance to flow.

 

The apollo tank system has more flow entering (top line?) than leaving (bottom line?) therefore the pressure drop due to an additional cooler should be less in the return pipe run.

 

The reason for the flow difference is the (small) bleed line flow into the cam cover.

 

In the real world, the most satisfactory hose routing and cooler position will also have a big part in where to site these items.

 

Ian

 

Green and Silver Roadsport 😬

 

Edited by - Mr Locust on 4 May 2006 20:33:43

[Delbert]

Considering an Oil Cooler at the moment. and comparing to a Laminova.

 

It seems to me that a Laminaove would be good for Track as the high Oil Temps are transfered into the water cooling system. With the water being cooler than the oil there is a benefit to be had.

However when touring in High temps the water temp is the same or slightly higher than the oil. Engine is under less stress etc.

 

In this example I cannot see where this exchange method of cooling is of benefit. It might be wrong but didn't a Laminava fitted car have issues with water temps in the states on the long drives or have I heard it wrong?????

 

So for touring it would seem logical to have a seperate cooler for the oil ?? As to where to fit it thats another issue to be considered.

 

Moving to Newark and yes I do know what its an anagram for

[Shaun_E]

If you fit a Laminova then you need to make sure your cooling system is up to the job. An old or damaged radiator would be a problem.

Before I upgraded to a dry sump, I had an Apollo and on track I would get very high oil and water temperatures. I replaced the radiator (black steel job) with a Radtec and fitted a Laminova at the same time. I never had high temperature issues after that and as a bonus the oil gets warm more quickly.

If you fit an air/oil cooler then you should fit a thermostat and a bypass circuit otherwise you will never get the oil warm enough in cold condtions.

There's plenty written previously on this subject - I suggest a search of TechTalk would be a good idea.

 

Yellow SL #32

[Bricol]

I've had an oil cooler (oil/air) sat on the shelf with be-spoke hoses to suit my Apollo installation (slightly different to std Caterham) and with a stat - - ran out of time to fit it before big Italy trip in 2003 - and still didn't have it fitted on last years 2000 mile Alpine blast - but this time I had an oil temp guage and the only time oil temps got worryingly high was on high speed motorway runs - and then took ages to come down in normal driving.

 

So before this years mega-miles in a week blast, I may just get round to fitting it.

 

Bri

[Blade Runner]

Thanks for all that. I have just got more to think about now. However i have been looking at where to mount the cooler, there does not seam to be anywhere that is totally satisfactory the best place appears to be infront of the rad but i think this could give issues with pipes chaffing on the rad and obviously longer pipe lengths.Are the ali rads any smaller than the std black ones especially around the top tank?

 

Trevor

[Mr Locust]

When siting an aluminium oil/air exchanger it is good practice to use some form of compliant mounting eg rubber bobbins. Reduces the likelihood of fatigue failure of the cooler flanges.

 

Ian

 

Green and Silver Roadsport 😬