Club 80-90 Forums

Well, there should be a ready market, as these diesels really do need an oil cooler when fitted to a T25, and above 90HP a fairly healthy one up front in clean cool air.

I have a oil cooler mounted in front of main rad, i can still get oil temp to nearly 120 degrees when in the hills. I would'nt like to think how hot it get without. It does'nt seem to have a bad effect on oil pressure, it still has just over 1 bar at idle at 100 degrees which is good for an AAZ. Engine has done 115k so its far from being fresh.

Thats a b* good engine.
Through lack of cooler and history in previous vehicle, mines not, but amazingly, she keeps going.

If the > 2000rpm oil buzzer and light comes on at 3000 rpm +, I reckon we're well over 130 degrees in hot weather on motorway, so then very careful cruise-climbing till 8pm when things cool down... gotta get one soon, nothing like 1 bar at idle
Nothing like 1 bar half the time when she's warmed up either

Cheers Andy, what size intercooler are you using? do you know what size pipe?
Looking around there seems to be a great variation of recommended sizes for an oil cooler, mostly say a 10 row will suffice but looking at some of the German sites then anything upto 23 row seems to be acceptable.
Thing is, is bigger always better? or is it a case of that the oil thermostat will regulate the temperature anyway so bigger is better.
I suppose, if it is bigger and does a better job of cooling then maybe the thermostat won't be open as much and not so much oil will be diverted to the front, so the pump isn't working as hard as it could...
It all boils down to what will fit in the gap too, I have a tech drawing of the appeture here and scale drawings of the coolers Im just trying to get the right balance of ease of fitment and performance.
Thing is, I want to make 1 kit, on the 2 wd T3's I would find it acceptable to mount underneath, but that ain't gunna work on a syncro, seems daft to make 2 kits when one will work

I know you say that mounting underneath on a syncro is a bad idea Simon, but theres lots of room there and with a louvred panel or duct it could be nicely hidden away without any fear of damage and with a decent airflow. You could have the oil cooler on one side and the intercooler on the other.

Mmmm, where exactly

Anywhere underneath on a sycnro is prone to damage when bowling along loose stone tracks, dontcha think?

Yeah but with adequate protection it might be alright. I mean between the sills and chassis rails up in there with some sort of scoop / protector to get the air in and keep it safe. You know in where the air pressure tank for the diff locks is. Up in there. Thats never been damaged in my van, nor has anything else up in that part.

My cooler is a 48 plate, but i think a 72 would just fit. Its fitted behind the lower grill. The thermostat is fitted near front of gearbox. The adaptor between oil filter housing and filter has a pressure relief valve incase the cooling system can't flow engough. I am totally paranoid about reliability so had proper hydraulic hoses made which complicate things becasue of the lack of give in them, the internal bore is 8mm which i was worrired about but works fine. I think the thermosat is always open after about 10 mins of running on mine, even with very gentle driving around town the oil temp sits just above 90 degrees, the thermostat opens at 80 ish.

I have a water intercooler on my syncro with the radiators mounted underneath, there won't be any issues with road or light off road use but would get ripped off over rocks etc but i don't intend on using mine offroad.

All worthwhile facts and figures, thanks.

Of course, if the watercooler side of amn air~water intercooler gets broken, this will only result in a loss of water, and performance. Oil's a different kettle of fish (oil)

Oh! Sounds like a BIG oil cooler that..

Pretty sure 8mm is bigger than the bore I've seen through the middle of some 1/2" BSP coolr pipe take-off sandwich-plate adapters. Going to go measure now

HarryMann wrote:All worthwhile facts and figures, thanks.

Of course, if the watercooler side of amn air~water intercooler gets broken, this will only result in a loss of water, and performance. Oil's a different kettle of fish (oil)

Oh! Sounds like a BIG oil cooler that..

Yes i meant to put that about its not the end of the world if it loses all its water. Also means the intercooler is very effienct, always a nice flow of fresh air.

The oil cooler sounds big but its not, its about 8 inches high, 10 wide, 1.5 thick. 48 small plates. Oil coolers are confusing because there are the multi pass types which are normally classed as low amount of plates but the physical size is big, and the one pass types which have lots of tiny plates.

HarryMann wrote:Thats a b* good engine.
Through lack of cooler and history in previous vehicle, mines not, but amazingly, she keeps going.

If the > 2000rpm oil buzzer and light comes on at 3000 rpm +, I reckon we're well over 130 degrees in hot weather on motorway, so then very careful cruise-climbing till 8pm when things cool down... gotta get one soon, nothing like 1 bar at idle
Nothing like 1 bar half the time when she's warmed up either

Is this with original water oil cooler or without.
Another option is to keep the original water oil cooler but set up an independant water system for it so it runs cold water instead of 90+degree water, this idea is also safe if a pipe or rad fails. I have done this on my friends bay window with a 2.7 911 engine because of not wanting to route very large bore oil pipes (1 inch internal dia)to a rad, he has had so much bad luck with engine we did not want to risk oil pressure loss. It has 2 small rads underneath, 1 with a fan so it keeps cool at low speeds. We did not do any before or after temp readings but before after 30 mins idling the oil filter was way to hot to touch, now with cooler it can be held for 30 seconds no problems.

Im hoping to keep the oil/water/heater/warmer/cooler thingy as it helps getting the oil up to temperature quicker, then let the oil cooler proper take over when it gets to temp.
I suppose though, if uber paranoid then the oil/water/cooler/warmer/heater thingy could be taken out of the vehicle cooling system and added to the charge cooler system..

what's 5/8s in a measurement I understand?!

so, 1/2 inch = 12.7mm
1/8 inch = 3.2mm
12.7+3.2=15.9mm, that seems big!

An interesting thread on 80-90 that hasn't been turned into a slanging match, imagine!

Simon Baxter wrote: An interesting thread on 80-90 that hasn't been turned into a slanging match, imagine!

I know! I created a monster! Im quite happy my thread has turned out so popular. So about the subject of undercarriage mounted oil or intercoolers, as I asked earlier. With adequate protection such as a louvred plate or something like that, is it a good idea?

In a syncro, it's asking for trouble. IMHO.
If you tuck it out of the way then you've lost your airflow.
Im not going to do it again, it worked well on the last one but if I am going to buy a kit and set it up then it seems daft to do it any other way other than to the front when the only thing you save is a few quid on some pipe.
I can't see any reason to do it any other way, I've learnt my lesson.
As for intercooler, I would be tempted to find a charge cooler that fites behind the left hand rear light and think of another way for air filtration, not so bad on 2WD but a bit of an a*** if you want to keep your syncro so it will wade without drowning.

HI Si, nice to see you are back.. little one and mum doing well?

I am after a cooler kit for my syncro (and the velle, but that aint on the road!!)
As mine is a doka, the air duct doesnt exist.. so a front mounted one is a good option, bigger oil pump? (wbx rememeber) But have considered cutting a hole in the side panel/opening the existing louvres a bit, for an oil cooler with a fan and temp switch on it..