Oil Coolers

Hi Gentlemen

After trying a couple of larger alternative oil coolers in the front of my exige they cannot keep the oil temps under 120 on the track. road fine 80deg-90deg, full on track action temp just creeps up and up…

I am thinking maybe the long and aging oil pipes are restictive. when I compare how small engine-bay side mounted oil cooler kits are which are seemingly giving a stable oil temp I cannot believe the front cooler cannot do the business.
Does anybody run/did run… the factory cooler set-up successfully on the track? I have seen pics of cars with ducting to put more air through/down to the cooler, but this cannot help much.

I have a pro alloy water rad to go into the car and I am thinking of getting rid of all that factory fitted oil cooling and get the Mocal heat exchanger instead.
What is the concensus about that?

Or is there an oil/air cooling solution which can be recommeded?


hi guys,

does anyone know what the size/type the fittings are on the factory oil cooler lines?

i am going to replace the oil lines and use the push in ends from speedflow, before i order the wrong ones i thought i would ask the forum. in the service manual and parts list there is no mention of such details.

also is there any advantage to increasing the oil line from 1/2" UP TO 5/8" diameter?

I would really appreciate your help here or i know i will be re-ordering…


1/2 Inch BSP Male on the cooler and on the adaptor

My guess is that if you want the temperature down you need more cooler surface area - I dont think larger bore hoses will help temperature very much.

You could add a laminova cooler in the circuit as well ?

A bit of info on oil coolers here clicky although it is in relation to the Toyota engine.

thanks for the info’s, we are still on 1/2" fittings…
there are many ways to skin the proverbial cat… at least i can order some pipe and end fittings to have a play with the coolers. nice idea to add a laminova, that combination would probably do the business.

option one was to open the clam side air ducts and feed air directly into the original oil cooler… better performance but probably just not big enough.

so then the idea was to add another cooler on the rh side of the car behind the front clam side air duct to assist the capacity of the original cooler.

then the nicer way, to put a cooler on both sides of the clamshell, a la mk2, this way both are in airflow and the compromised position of the original oil cooler is removed.

why didn’t lotus just check it was big enough before they sold the cars… :smiley:

The setup on my car is as per a Mk2 with a cooler on each side fed through the front side ducts. Works very very very well. In fact almost too well! If you do it that way you wont need huge cooler rads.

I am going to size up the coolers and decide what to do for mounting and ducting.

I thought about the Mocal 115mm 25 row cooler for a start size.

115mm Matrix
25 194mm 0.30l 0.84kg

What cooler are you using Sean?

any chance of a picture or two to see how you have orientated and mounted the coolers and ducted the air?

Or have you pillaged a mk2 for the grp housings…

No housings, I just knocked up some brackets to hold the coolers to the crash structure and floor.

I fitted an extra oil-cooler inside the engine bay on top of the right-hand wheel arch in the air flow from the right side clam duct.Seems to work although I think oil temps will always be high if you track an Exige.

Timely post.

Some years ago I swapped the original thin oil cooler fitted at the bottom of the crash structure by a much bigger one below the radiator (about half the size of the radiator).

Woked very well to keep temperatures at bay, but now my hoses are cack.

They have been cooked and needed replacing years ago, and now that I want to put the car on the road again find they’re cracking with as little as a small bend.

I already bough some high-temp hose, but has anybody replaced these hose?

My question is, how are they held in place? if I just pull them through the hole and pull the new ones, is there any special precaution I should take?

Hi Uldis
I replaced mine - it was a real PITA …
Some things leart from my experience …

  • Make sure the new hose is very firmly attached to the old before you try and pull it through - I didnt and then you have a big problem

  • Pull through from the rear and have an assistant thread the hose and new hose from the front, so they can push down into sill and then you pull … trying to just pull doesnt work due to the “S” bend at the front from sill up to the inside of wheel arch

  • One of mine was stuck with Sikaflex to the sill which meant that I had to remove the coin tray on the RHS to get a hand down to pull it. As the coin tray is fixed with the damn stuff as well that destroyed the coin tray … so last resort

Oh - I also cut off any fittings first - they can get caught in the sill - new hose was without fittings and I put the ends on afte rI pulled them through …

Dunno if you guys are aware, but there is an alternative for the ‘K’…


Well I have just finished my installation…

I have kept the original one under the floor, and added an additional oil cooler in the right hand side behind the duct, which i have opened up… I plumbed it in series with the original one with the addition of one short extra hose, couple of brackets and little rubber bobbins.

I formed a small mesh of similiar design to the main grill on the crash structure opening to keep out little pets and other things, i trimmed a hole in the wheel arch liner to let the air out behind the cooler too. Also fitted with a suitable protective mesh. Although the giant hole in the wheel arch liner from compressions going through the fuchr�hre at the n-ring should do the trick…

I have added a couple of snorkels to better direct feed the original one, bit of alu ducting sprayed black… and jobs a good 'un.

First tests are showing cooler oil temps. Hopefully getting on the track this weekend and then see how it keeps up…

cool man, coolers behind the ducts is totally where its at for oil cooling

I have a 235mm x 34 row cooler mounted to the crash structure directly under the water rad. The nice thing about this set up is that it’s extremely effective - I have never seen over 100 degrees even after a proper hour long stint on circuit, it just steadily creeps up into the 90s and stays there (a bit like my fashion sense)
The side benefit is that if you decide to switch the fan on it cools the oil too! The ducts are required for brake cooling duties.

The oil cooler under the water rad is a great installation. I still have the AC on my car so this is not possible hence my need of an alternative solution. With regard to the brake cooling ducts, we did some brake disc temperature testing at a track with those special paints, three colours for three temperature bands, it is a tale-tale of how high the temperatures get. I have already bought some ducting and was ready to start installing brake cooling, but after a summer days driving at Hockenheim which is really tough on the brakes the temperatures were safely within the working temperatures of the pads. So in fact I have 3m of brake duct for sale if anyone is interested :wink:

My new oil cooler set up working a treat. Didn�t see over 100 degrees the whole weekend. That was with 40min non stop on the track. So I am pretty happy with the setup now. Just need to add a thermostat to allow swift warm up, at the moment I gaffer tape over all the holes and snorkels and tickle about until it�s up to temp, but that is only until the thermostat goes in.

There is a EP kit for the K series, sandwich plate and smaller oil filter (due to manifold) mounted on a standard filter adaptor to the block, has anyone done this? It seems like the neatest way of doing it. Otherwise there will have to be new hoses and try to find space to mount the thermostat unit. Alternatively add bits of string to my gaffer tape covers so I can remove them on the move from the driver�s seat� any tips regarding oil thermostat experiences would be greatly appreciated.

Some peeps are of the opinon that, if anything, the engine works better with a higher oil temp (within reason) if using a fully synthetic oil. I have an (admitidly cheaper Stack) oil temp gauge that regularly shows 130 degrees c during a track session.

Is there any truth in this, and hterefore should I be worried? Is it best to get the max temp down to 90 - 100? Any thoughts anyone - Edwards boys / DVA / Pesky?


I’m no expert (obviously, 'cause I’m not on your list of invitees above :wink: ) but one of the quoted advantages of synthetic oils is that they remain stable at high temperature… Whether that extends to 130 degrees I have no idea.

I shouldn’t worry, Clive has listed Pesky as one of his experts, now that is a frightening thought!!