Thread: R380 oil cooler 110 tdi

I have mounted my oil cooler on the radiator 250mm x 150mm x 45mm. Took the car for a run yesterday for 60km and the transmission now hardly gets warm to touch. (unlike the transfer case) One of the things I noticed while installing is that the cooling pipes are always open to the oil pump so I suspect that the thermostat must just close a gallery between the oil pump ports so oil can ONLY go through the cooler when things get hot. I think I proved the point this morning when I took it for a 20km light run to the shops and felt the cooler pipes when I got home. they were warm to touch (no more than 50degC) and the same approximate temp as the tranny, so it appears there is always a certain amount of oil going through the cooler. This makes sense as it would help prevent airlocks.
As far as the oil pump capacity is concerned I doubt there will be a problem with head (say 600mm) as it is a gerotor design and should handle "reasonable" pressure. Since its ports are quite small half inch pipe will not cause any restriction, even over the 5.5metres of line I have used to get to the front of the car and back.
cheers all.

whats the advantages or differences in the thickness of a cooler. Farmport's is 45mm and the one im looking at is 19mm. Would one be better in a situation such as what I want that has less air flow than in the front of the truck???

Farmport, do you have any idea of the PSI that the pump will run and therefore the cooler need be able to handle

In a thick cooler the back of the cooler is subjected to preheated air that has been heated by the front of the cooler, therefore the rate at which you can transfer energy is reduced as the air travels through the cooler. If the area that you can use for the cooler is limited then thickness will help but you will not get as good a bang for the amount of material used to make the cooler, after all multiple core radiators do provide additonal cooling. You will get better efficiency if you can get the same volume of cooler in a thinner wider package.

In a confined space without forced air it probably wont make a difference and the volume and material that constrains the confined space will be more important as you will have to transfer the heat via the surface of the constraining volume.

Purely opinion as I have limited experience and training in heat transfer.

There are 2 common types of oil/transmission cooler. The least expensive is the one with a thin profile and a single round pipe that goes back and forth through the cooling fins. The other, like I have used, has a manifold at each end and a series of flat cooling tubes, full thickness of the cooler, running between the manifolds. Because these tubes are flat/thin it is necessary for them to be wide to allow sufficient oil flow. These are the most efficient as there is much more oil contact to cooling surface than the round pipe design. They also enable much better cooling capacity with minimum length and height.
For the R380 I don't think it matters much as it is a manual transmission and doesn't suffer the heat production of an auto from torque converter slippage so anything will help a lot and whatever fits in the space available will help a lot so long as there is SOME airflow.
As far as pressure is concerned there doesn't appear to be a pressure relief valve and I can't find an exploded view of the adapter plate anywhere to read the circuit.
The oil pump suction pipe and ports in the gearbox extension housing are about 6mm in diameter so pressure buildup through excessive flow through a cooler is unlikely so long as the cooler has at least 3/8" ports(I used 1/2")
So in terms of cooler and hoses/fittings used if you treat the installation as if it was an auxiliary auto box cooler you Should be fine. My circuit is rated at 200psi which I am sure is massive overkill.

Thanks Farmport,
I am looking at the PWR range and was under the impression they made fairly good stuff. What brand did you use and any you would recommend? Im now looking at PWR engine oil cooler range as they are 37mm thick and have 1/2 inch fittings available as apposed to the 19mm thick ones which have a max of 10mm....

cheers,
Serg

I am sure PWR are a good cooler and one of those would be fine. I would go with the one you mentioned as it will be fairly robust with the larger fittings. I brought a cooler in from China so it doesn't have a specific brand. Bit of a risk but I am very impressed with the quality. Most brand name stuff is made in China these days anyway.

Cheers

Originally Posted by justinc

Definately need the 2 pipe Orings, they are the same size as the engine oil cooler line ones for the Tdi.

JC

JC, I was speaking to a hyd guy today and he seemed to think it was a non-O ring fitting, ie metal to metal???

so where does the Oring go, seal against?

when you say they are the same as the oil cooler line (tdi) do you mean the ones that go in the T/Stat housing to gearbox?

on another note, the cooler im fitting has AN-10 or AN-12 fittings. I believe they are Army-Navy or Air force-Navy design, which has the same 37° taper as JIC hyd fittings. Im hoping I can use JIC hyd fittings to it which will work with the Hyd/oil hose I want to use....

cheers,
Serg