Oil Temperature

[judson]

Can anyone tell me what is the typical oil temp range for any and all models?
I've been doing a lot of oiling system related research on my 907 and need some comparison numbers.

thanks.

[JeffYoung]

Going by the stock gauge, I would say normal operating temp on a cold day is 40 to 60 degrees celsius. On track days, I see 80 degrees but never anymore.

This is the stock gauge however. Probably not the most accurate device in the world.

[rlearp]

Judson, mine is around about the same as Jeffs. On track days the thing will creap up a bit as he indicated, and it will do the same during hot weather stop and go driving. I bet the stock gauge is within 10% or so, at least on the temps. Now, the stock gauge on oil pressure I'm not so sure of since mine, on a 95F day at idle, will damn near read a tick off of zero, which I don't believe. Especially since it has done that for over 1.5 years and I'm still kicking with no knocks or funny noises at all.

[lotusguy]

Hi,

Jeff and Ron are right in the Ball Park on their numbers. This assumes proper airflow through the oil cooler (read not clogged with debris) and flow through the system (read properly operating oil pump and a system free of sludge etc.). But rest assured that the oiling system in the 9XX engine is one area that doesn't lack in terms of design or performance.

Realize too that these only have value if compared to a relevant number. Not the operating temps of other engines, rather the operating temperature range of the oil itself. Use Mobil 1 with it's extended operating temperature range over conventional oils, and you are well within it's capabilities.

Not only does the oil provide a film on which to float the internals, but, contrary to a commonly held belief, fully 60% of an engine's cooling is accomplished by having the oil carry away the heat from internals. This emphasises the importance of keeping the system in top tune.
Happy Motoring! ...Jim'85TE

[JeffYoung]

Jim, just wanted to emphasis your point on oil cooling. I had no idea the importance of this until I started racing. Adding an oil cooler to the car helped overall cooling tremendously. People think it's all in the water, but it's not. Oil lubricates and cools.

[rlearp]

I don't think I'd agree that the 9XX engine dosen't have oiling issues, Judson is well versed in this. In fact, I'd disagree. There is plently of evidence from those that race the car that show otherwise.

I don't know it first hand, but from the racers it is well known starvation can be a problem while racing with the 907 due to oil pan design and I think the 910 as well - just ask the E Prod racers who learned this first hand. Boom! And, the series also wants to pump WAY too much oil into the head/cam towers than needed. The holes in the block are small, and, do not provide adaquate draining back to the pan. I do not know if these basic flaws were fixed on the latest iterations of the motor, but I suspect they are still there.

Judson fits restrictors on the oil flow to the head and I think I will follow his advice. I can't do anything about the pan design, but I can use an Accusump to make sure that if the things gets starved there will still be oil pressure going into the motor.

Ron

[JeffYoung]

Actually, you can do something about the pan design. Baffles, windage trays, etc. are free.

Might want to take it off and have T-Hoff weld you up some baffles in addition to the Accusump.

Jeff

[lotusguy]

rlearp said:

I don't think I'd agree that the 9XX engine dosen't have oiling issues, Judson is well versed in this. In fact, I'd disagree. There is plently of evidence from those that race the car that show otherwise. I don't know it first hand, but from the racers it is well known starvation can be a problem while racing with the 907 due to oil pan design and I think the 910 as well - just ask the E Prod racers who learned this first hand. Boom! And, the series also wants to pump WAY too much oil into the head/cam towers than needed. The holes in the block are small, and, do not provide adaquate draining back to the pan. I do not know if these basic flaws were fixed on the latest iterations of the motor, but I suspect they are still there. Judson fits restrictors on the oil flow to the head and I think I will follow his advice. I can't do anything about the pan design, but I can use an Accusump to make sure that if the things gets starved there will still be oil pressure going into the motor. Ron

Ron,

I'm with you on baffling and potential oil starvation with respect to high lateral 'G's. I was referring more to the delivery, pump, pressure, cooling etc.

The earliest 9XX engines has terrible baffles, but these were constantly improved to the point that they are certainly adequate for a street machine. Racing is definitely another story, but of course it always will be.
Happy Motoring! ...Jim'85TE

[judson]

Guys,
Thanks for your help, and Ron thanks for the vote of confidence...

I cannot stress enough the need to compare your research (and hard data) with others through forums such as ours. There are plenty of people with opinions, but it's the hard numbers that really help us all.

As far as baffling goes, I'm convinced the 910 bottom end is more superior to the 907...but in a racing situation, there is no substitute for a dry-sump system.

If you have low oil pressure at idle, that is usually a sign that the oil pump rotors are worn and the lobe-to-lobe clearance has exceeded the ~.006"(.005"?) spec. I've seen rotors w/ over .012" clearance pump oil, but not build much pressure; especially when the engine heats up.

I will tell everyone that when I started my research, my 'stock' Jensen-Healey driving around town routinely had 210^F oil temp and 160^F water temp. Alarming since 230^F is the generally accepted max temp for regular oil.

After a lot of work, research and numerous modifications, I was able to get my 907 running closer to 160^F for both under racing conditions with 95^F ambient temperature. Too bad it took about 5 years to figure that one out!

Thanks again to everyone for their help!