| Author |
Message |
Lawrence Coppari (Lawrence)
Junior Member
Username: Lawrence
Post Number: 109
Registered: 4-2002
| | Posted on Wednesday, July 10, 2002 - 9:05 am: | |
All P-cars that I am familiar with have oil coolers.
My 328 would hit 250 F oil temperature when on the track in hot weather. High rpms cause it to happen. |
Verell Boaen (Verell)
Junior Member
Username: Verell
Post Number: 182
Registered: 5-2001
| | Posted on Wednesday, July 10, 2002 - 8:48 am: | |
(NFC but related)MAZDA Rotaries get a very high % of their cooling from a huge (~4" x ~20")oil radiator. Oil is circulated thru passageways inside the rotor to keep it cool. Also the turbos are cooled by both oil & water.
I agree with your point, commonly US cars depend on the coolant to dissipate the heat & oil only spreads it around in the engine to where the coolant can pick it up.
However, almost all RV places recommend & sell an add-on oil cooler setup to customers buying all but the smallest camper trailers. |
Edward Gault (Irfgt)
Intermediate Member
Username: Irfgt
Post Number: 1555
Registered: 2-2001
| | Posted on Tuesday, July 09, 2002 - 9:45 pm: | |
My Turbocharged air cooled Corvair normally runs cylinder head temperatures in excess of 450 degrees and holds only 5 quarts of oil. It has a small factory equipped oil cooler and no oil temp gauge but you can only imagine what the oil temperature runs up to with no problems whatsoever. This is on a 38 year old car that used oil with the technology of 1965 plus the fact that the turbocharger is lubed and cooled by the same engine oil. Using this example, I doubt if a Ferrari should ever have to worry about oil temperature. |
Bill Sebestyen (Bill308)
Member
Username: Bill308
Post Number: 271
Registered: 5-2001
| | Posted on Tuesday, July 09, 2002 - 8:06 pm: | |
I suspect the P-car also has an oil cooler, fan, and perhaps ducted fins. How about a motorcyle? Ultimately, all heat must go to the ambient air, except in the case of boats, though the paths vary. |
Hans E. Hansen (4re_gt4)
Junior Member
Username: 4re_gt4
Post Number: 56
Registered: 4-2002
| | Posted on Tuesday, July 09, 2002 - 7:25 pm: | |
Bruno: Yeah, I guess what I was getting at is that in an American car, oil is responsible for maybe (I'm TOTALLY making these numbers up) 35% of cooling responsibilities, and in the Ferrari V8 it's more like 50%-60%. Also, it appears that there is some division in the duties of coolant (combustion cooling) and oil (friction cooling). At least this is the impression that the design leaves. Also, good point about the Pcar. They say 'air cooled', but I'm sure the oil, at a minimum, spreads the heat around a bit. |
stephen r chong (Ethans_dad)
New member
Username: Ethans_dad
Post Number: 48
Registered: 3-2002
| | Posted on Tuesday, July 09, 2002 - 7:01 pm: | |
Hans:
Consider the Porsche Flat Six motor;
2.7~3.6 Litres. The Pcar motor uses 12qts of oil as a coolant. Has worked for years!
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Bill Sebestyen (Bill308)
Member
Username: Bill308
Post Number: 270
Registered: 5-2001
| | Posted on Tuesday, July 09, 2002 - 6:56 pm: | |
Without an oil cooler, oil acts more as a heat transfer medium, taking heat from hotter parts of the engine, like the cylinder head, and distributing it to cooler parts within the engine. The engine has external surface area, so hot oil slung onto the internal sides of the block, transfers to the external sides of the engine block, which will reject it to air in the engine compartment, if the air is cooler than the block.
An oil cooler is essentially a secondary radiator. Heat rejected by the oil cooler may be added to heat rejected by the coolant radiator, the external surface of the engine block, and all the coolant lines, including the oil cooler lines. |
bruno bandaras (Originalsinner)
Junior Member
Username: Originalsinner
Post Number: 222
Registered: 5-2002
| | Posted on Tuesday, July 09, 2002 - 6:33 pm: | |
I was told that engine oil is responsible for 40% of an engine's total cooling. |
Hans E. Hansen (4re_gt4)
Junior Member
Username: 4re_gt4
Post Number: 54
Registered: 4-2002
| | Posted on Tuesday, July 09, 2002 - 5:49 pm: | |
The following is related to the discussion in "Dino Help Sought" and is probably obvious to the serious gear heads out there, but...
When driving with low rpms (say 3K-4K) and heavy throttle - common with the long hills around here - the water temp climbs. Not seriously, but a noticeable amount. This is obviously normal, as extra combustion will heat the water.
However, last night I was behind a truck waiting to pass. Level ground, 3rd gear, light throttle at 5000+ rpm for several minutes. Water temp steady, but oil temp climbed!
This would imply that combustion heat is handled with coolant, and frictional heat is cooled with the oil. I said this may be obvious to some of you, but for an American car guy, it is a bit of a revelation. American V8s have about 1/2 the oil capacity of a Ferrari V8, and seldom have oil coolers. More of the burden of frictional heat dissapation rests with the coolant. And, yes, it is possible to cook the oil in American V8s.
What I find interesting is an apparent difference in philosophy. US cars -> oil is lubricant. Ferrari -> oil is coolant as well as lubricant. Yes, I know, this isn't a black and white issue, as oil does cool parts it touches. It's just that Ferrari uses an abnormal amount of oil with a large oil cooler, and apparently the internal parts are totally bathed in the stuff. Oil is a more integral part of the cooling system. |
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