oil coolers

lotus · 29 Nov 2004, 19:52 (Ref:1167348)

Hi all, has any one had any problems with oil coolers leeking I had two go last season is there a correct way to mount them ie on rubber mounts ?

thebear · 29 Nov 2004, 23:45 (Ref:1167556)

Quote:

Originally posted by lotus
Hi all, has any one had any problems with oil coolers leeking I had two go last season is there a correct way to mount them ie on rubber mounts ?

:confused: Are you sure it was not from overpressure?

StephenRae · 30 Nov 2004, 09:17 (Ref:1167796)

Oil coolers are best retained on a soft surface by 'Hoover' rubber bands. With modern synthetic type oils you would be surprised what you can get away with... have you tried running without?

greenamex2 · 30 Nov 2004, 13:39 (Ref:1168043)

I am afraid all welded oil coolers are the only real answer. They cost and weigh a bit more but will last a lot longer, including the odd meeting with solid objects that would otherwise cause the typical oil cooler to become unpressed.

Personally I still don't see how a normal oil cooler stays together AT ALL, let alone for any length of time on a race car!

lotus · 30 Nov 2004, 22:05 (Ref:1168386)

hi what pressure can oil coolers take my car runs about 50 psi thay all seem to have burst ?

thebear · 1 Dec 2004, 00:45 (Ref:1168513)

Quote:

Originally posted by lotus
hi what pressure can oil coolers take my car runs about 50 psi thay all seem to have burst ?

Should be good for 100psi at least, assuming that it is specified for racing and not automatic transmissions.

hrug:

greenamex2 · 1 Dec 2004, 08:15 (Ref:1168668)

My car has run to over 100psi on a normal oil cooler and not experienced the problem you describe.

It really does sound like you have a mounting problem of some description.

StephenRae · 1 Dec 2004, 09:16 (Ref:1168722)

I guess the cooler is plumbed into the pressure side of the system, if your car is dry sumped the situation can be eased by plumbing the cooler into the oil tank return.

boyracer · 2 Dec 2004, 09:23 (Ref:1169598)

Firstly, distrust anyone who says "Oil coolers, you don't need them". I've seen race cars that within 5 minutes of starting up from dead cold, you can't get your hand anywhere near, let alone place it on the cooler. All that heat is trying to breakdown your oil, coolers are good.
Secondly, have seen several oil coolers solid mounted on race cars, rally and tarmac. Rubber mounting while it's probably techinically correct is not necessary to stop your cooler from popping. The main thing is that the mounts don't move relative to one another and try to stretch or compress the cooler.

I've personally presure tested (for a short duration admittedly) a cooler to 150psi, if you're getting that sort of oil pressure I'd have to ask, why ? Otherwise normal running oil pressure should be fine.

Use BIG lines, look at the biggest that you think you can reasonably fit and then go one size larger.
When tightening the fittings be sure to hold onto the hex on the cooler as well. Otherwise as the material is sooo thin you may well crack it just by tightening the fittings.
That's my piece said.

StephenRae · 2 Dec 2004, 09:52 (Ref:1169612)

Boyracer...I'll bet that your idea of dead cold is somewhat different to mine, there are many race cars which neend all the cooling they can get but in the ideal world shoulden't the heat, which is the bi-product of combustion be removed via the cooling system? If this is done successfully then synthetic oil should cope with heat created by friction.

boyracer · 2 Dec 2004, 10:06 (Ref:1169623)

Show me someone living in the ideal world and I'll show you a pink pig with a tutu in full flight across the northern sky.
The car in question has no problems with the cooling system and never runs hot. Where the oil cops the hiding is from conductive heat from all the components within the block. In this motor it does have piston coolers (though no turbo) so the oil is in contact with the forged aluminium pistons and no doubt a fair bit of heat comes back to the oil that way. Even so in most modern day motors the head is alloy, and oil drains off that (after lubricating all the rockers) and the heads contains the cooling water, the oil is not ONLY coping with frictional heat (which is probably not a hell of a lot in the scheme of things) but the heat being conducted through the conrods, block, head and any other component it comes in contact with.
Anything you can do to take the heat out of the system, or even to keep the temperature more stable (you can get thermostats for plumbing into oil systems) has got to be a good thing, synthetic oils or not.

**dtype38** · 2 Dec 2004, 13:26 (Ref:1169828)

We seem to be getting a bit off thread with this one. Oil cooling is a very interesting subject and I have my own views on that, but at the mo we are trying to solve lotus' cooler failures...

lotus, we've determined that your oil pressure is well below what a cooler should take, but that you've got it solid mounted. That still leaves plenty possibilities... Can you be a bit more specific about how exactly the cooler is failing? Is it from between the fins, mid cooler or at the end, where the connections attach etc. Is it splitting wide open and dumping all your oil out, or is it just an anoying weep?

lotus · 2 Dec 2004, 18:11 (Ref:1170085)

phew, right mounting threaded bar through two holes with lock nuts top and bottom and in the middle so not putting presure on flanges.Both the mocal coolers failed at the ends where the pipes are and i used two spanners to tighten the nuts up they both lasted about four races with heavy oil loss with oil on the exhaust lots of smoke.Do you think it would be better to run wihout the cooler which would be more reliable as it cost me two races last year

**Tim Falce** · 2 Dec 2004, 18:57 (Ref:1170114)

lotus, what is the actual engine you are using and what sort of oil pressure are you getting when cold? How tight are you doing the pipes up, how are they mounted, what size and sort of pipes are they and what size fittings are on the cooler? You may have the pipes rigidly mounted in relation to the cooler causing stress, can you email or post a photo of the set up.
Tim

Red Dog · 2 Dec 2004, 19:58 (Ref:1170159)

Lotus

What oil temperature are you running at? Where is the temp sender located?

If you remove the cooler but your oil temp is still too high you can use the water/oil type cooler (Laminova) if your water system has spare capacity.

**dtype38** · 2 Dec 2004, 21:26 (Ref:1170259)

Its worth sending falcemob a photo, he's quite good with oil systems. In the mean time, personally I think you've got a simple mechanical stress problem and its nothing to do with oil pressure or temperature. I would hazzard a guess that its vibration/movement related and is either being caused by the cooler "flapping" on its mounting when you're on track (you might try a stay from somewhere to the left side of the cooler to support it), or possibly its oil hose vibration causing failure near the hose connections (for this try clamping the hoses to the chassis before they connect to the cooler so that engine movement can't vibrate/flap the hoses). Good luck.