Brinkley

I am running a 996 motor in a dedicated track car. I am wondering if the engine builders/shop owners could answer the question:

What oil temp is too hot for a 996 motor?

And:

If oil temps are too high, what is that an indication of? other than "not enough cooling". Could it mean the synthetic oil has broken down and lost its abilities to lubricate properly or anything like that?

utkinpol

Above 275 is bad. What to do if you already have 3rd center radiator installed - not sure, custom oil coolers most likely.

Martin S.

I got a RLC Data Logger. I also bought a oil pressure and oil temperature senders. I have 220 programmed as an early warning on oil temp. When the oil hits 220, the oil term light turns red. I have 270 as the critical temp. If that were to occur, then the whole 7 1/2 "" display turns red. I'll know!

Oil pressure, don't recall what I programmed, but when it drops to the critical level, the whole dash goes red, with the alpha numerics.

utkinpol

i got oil above 270 one time only when track was measured at 135 degrees and on my 997 car water temp which gets 'stuck' at 175 will also start moving when it gets above 225 or so - so overall when I see water temp moved up from vertical position - I slow down and drive on 4th gear lap or 2 to cool down. i did not see pressure level to get severely altered at high temp but i run 5w50 or 15w50 oil only and it does not deteriorate as bad as 0w40 does.

Brinkley

Martin S....you say you have 270 as a critical oil temp but warning light at 220. That seems like a large difference. Is there any reason you selected those two numbers. I don't have the OEM gauges, I have a MoTec Dash so I don't know where the needles would be, I just read actual numbers.

At Sebring this weekend, Air Temp was mid 80's. I log inlet air temp which is measured right in front of the throttle body, it was consistent at 100-104. I saw 240 oil temp. Water temp was 189-192. I have three water radiators up front but rely on the stock oil cooler on top of the motor.

Matt Romanowski

I've always been told by oil engineers that 220 F is where the oil starts to breakdown quicker. It's something like half the life for every 10 degrees over 220 F.

d15b7

hello. one of the gentlemen I've been coaching fairly frequently has a stock 2009 Carrera S; on a warm day (80+ deg) the oil temp typically stablizes at 250-260 on the gauge. the water temp is always dead in the middle (I suspect it is 'damped' as I never see it move). just FYI.

Todd
ReidSpeed

Brinkley

Matt, I too have heard of this magical 220 F number as the critical number when oil starts to break down. But then Todd and Paul report temps of 250-260 and 270 F. I wonder what Porsche states as "normal operating temp range" on their water cooled 996 "street" motors?

Does anyone know where that might be listed or discovered?

d15b7

hello again -- I tend to think that 220-230 deg oil temp is in the 'perfect' range; but most street cars want to have their oil temp at that point just in 'normal' everyday driving; the oil needs to be over 210 at a minimum each time it is driven in order to flash off moisture, etc. for economy, and emissions, it is also preferrable to have oil temps of 220+, too.

problem is that if the oil cooling system is sized for a 'real street' car, it is easy to keep the oil temps in check (this not considering that the car will ever see a real racetrack). thus, most cars have undersized oilcooling systems for track use (see Corvette, most newer BMWs, and most P cars that are not 'specialty' cars -- GT3 etc). my Japanese cars are a good example -- both my honda civic and my ford probe (mazda) will peg the oil temp gauges at 300+ on a 20 min session; but they are japanese and seem to be able to 'take it' -- the probe has over 45k track miles (yes! that many) and i have never fitted a bigger cooler; i change the oil twice a year (mobil 1) and it lives... same goes for the honda.

when my Lotus Super Seven approaches 240 deg on the oil temp, i panic and start short shifting; it WILL NOT stand high oil temps (been there, destroyed that). different engines/designs seem to be able to withstand differing amounts of conditions.

the 2009 Carrera S that I coach has done perhaps 10 events total, and seems to have no issues with 250+ oil temps. ymmv!

Todd
ReidSpeed

bgiere

above 250ish is what would worry me. below that you're fine. If it creeps up there add an oil cooler with a thermostat. BAT Industries in Florida has a web page with some neat descriptions.

utkinpol

'normal' temperature is not stated anywhere I could find it. on the street 'normal' is set pretty much between 220-225. as none of M96 generation motors was 'intended' for track duty i do not think you will find anywhere what is considered 'normal' after having it running close to redline during 15-20 min session.

on 80deg day you will get oil to 250 somewhat after 4th lap and it usually stays there. on hot summer day it will get higher if you`ll keep pushing motor to the max. that is pretty much default rule is to replace oil after every second DE event and also running _W50 oils instead of _W40.

onefastviking

Umm..... to answer your questions.

"What oil temp is too hot for a 996 motor ? " - It's really not oil cooled so if you are getting too high of oil temps I would look at your coolant temps and ask why they aren't doing their job properly.

2nd question "What is that an indication of ?" Broken down oil would be one possible, too much friction somewhere could be another, bad engine coolant system another.

Are you trying to solve a problem of just wondering to make sure your car is ok ?

J richard

For the 944 spec car I've had 240-260 during a race is pretty normal, spikes to 280 start to worry. Temps will peak in the twisties or right on the tail of another car in the heat of battle, but then cooling down on the straights. If it sticks over 280 it's time to back off and cool down, which is not easy in the middle of a race. This is oil temp in the pan, you can get spikes all the way to 300 with the water sitting at 220.

Brinkley

Viking,
The question was more on the line of is this temp ok or should I start looking for a problem. As mentioned previously the data from MoTec is showing coolant at about 190 F during the entire 30 minute session and oil rises as I start the run and levels off at the 240 F. It gets to 240 in a lap or two then stays flat through the full 30 minutes.

I was just wondering if that high of temp could mean bad news is around the corner. It sounds like that number is "normal". I'll just change my oil more often.

amso3

Brinkley

I've worked on a bunch of 996 and 997 Cup cars. I usually set the oil temp alarm at 250. At NJMP Grand Am race last year our oil temp was in the 270-280 range (air temp was 115) for a 2.75 hour race. I'm not saying 270 is good, but the engine did not explode. I think Matt's comment about 220 degrees was about non-synthetic oils. Mobil 1 and good synthetics can take 250 all day long.