2eighTZ4me Posted August 12, 2009 Share Posted August 12, 2009 After about 2 laps around Road Atl. at speed, my oil temp reaches 250 and stays there for the remaining 7 or so laps. I have an external B&M oil cooler mounted in the front of the rad., plumbed with -10AN lines and through a Mocal thermostat. I was told by a racer friend of mine that that might be just a little on the hot side. What do you guys normally reach under full load and haulin' azz? Quote Link to comment Share on other sites More sharing options...
z-ya Posted August 12, 2009 Share Posted August 12, 2009 The oil in my turbo car runs somewhere between 250F and 280F on the track (depending on ambient temp). I also have an external oil cooler but with -8AN hose. I run 20W50 synthetic to be safe. Done many track days with this car and the motor (stock internals) still runs strong. Pete Quote Link to comment Share on other sites More sharing options...
rxsleeper Posted August 12, 2009 Share Posted August 12, 2009 250-260F is the norm for me but at Nashville in June I saw 280F. Ambient was 96F and we had a 20 minute black flag as well. Maybe it is a little high, but generally I think 250F is about average for a Z under racing type conditions. Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted August 12, 2009 Author Share Posted August 12, 2009 Well - it was John Williams (our buddy!) who suggested that I might have a bearing clearance problem that might be causing the high temps. Maybe he's such a cool cat that his oil doesn't run as hot as ours! It was 95 degrees ambient under full sunlight all weekend. 140 degree asphalt temps. Not pleasant racing weather to say the least! Also - do you guys change your oil after every track event? I've heard it's a good practice, and after 8 sessions b/t Sat. and Sun., I would think the heat cycling would break it down a lot quicker than normal day-to-day. Quote Link to comment Share on other sites More sharing options...
z-ya Posted August 12, 2009 Share Posted August 12, 2009 For the track only car, which does around 10 events per year, I do the following: - Engine oil every other event - Trans oil once a year - Differential oil once a year Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted August 12, 2009 Share Posted August 12, 2009 (edited) in an ideal world youll want to keep the oil temps below 240f NOW 250f IS NOT LIKELY TO CAUSE ANY PROBLEMS SINCE YOUR PRESUMABLY CHANGING YOUR OIL AND OIL FILTERS FAIRLY FREQUENTLY, but the lubrication properties of the oil and shear strength tend to degrade above 240f faster than below that level, IF it was my car Id swap to a LARGER oil cooler WITH AN INTEGRAL ELECTRIC FAN http://www.summitracing.com/parts/PRM-12318/?image=large I use this one now ON my corvette it was the auto transmission that needed to the cooler more than the engine because I installed a 10 qt custom built oil pan and it had a factory oil cooler but once I mounted that trans cooler where the spare tires normally mounted(there was no room up front) I found BOTH the engine oil and engine coolant temps also dropped a few degrees, because the transmission was not adding a heat load to the engine coolant keep in mind oil needs to exceed 215f to burn of moisture that forms acids that are bad for the bearings, Ive always tried to keep the oil in the sump in that 215F-240F range, a large capacity baffled oil pan and a decent oil cooler can do that, but youll need the electric fan if you can,t locate the cooler in direct air flow http://forum.grumpysperformance.com/viewtopic.php?f=54&t=296&p=361#p361 Edited August 12, 2009 by grumpyvette Quote Link to comment Share on other sites More sharing options...
johnc Posted August 12, 2009 Share Posted August 12, 2009 Where are you measuring the oil temps? If its 250F going into the cooler then you're fine. If its 250F coming out of the cooler then you probably need to increase cooling capacity. Oil changes every other even worked fine for me especially if you're running synthetic oil. You cna also use an oil testing service which will give you a lot of information about the condition of the engine and the oil. Quote Link to comment Share on other sites More sharing options...
z-ya Posted August 12, 2009 Share Posted August 12, 2009 I'm measuring temp in the oil pan with an immersed sensor, which I'm assuming is probably the hottest location that is measurable. BTW, I have an electric fan mounted to the radiator that pulls air through the oil cooler and radiator (in that order). Pete Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted August 12, 2009 Author Share Posted August 12, 2009 I have an inline sensor bung that is mounted on the inner fender well. I come out of the motor > remote oil filter > oil temp sensor > oil thermostat > oil cooler > back to the inlet on the block. I too have a Spal puller fan on the radiator, however, my oil cooler sits about 4" in front of the radiator, so I would imagine airflow from the fan would be somewhat deprecated due to distance. The fan only kicks on when water temp reaches 195 degrees - which it never gets to when I'm running on the track - usually stays right at 190, so the fan doesn't kick on until I get back into the paddock after taxiing down pit lane out to the paddock. Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted August 12, 2009 Author Share Posted August 12, 2009 Also - I've been using Valvoline VR-1 20w50 and a can of ZDDP each oil change. You guys seem to lean towards the synthetic. Would Mobil 1 be the oil of choice? I'm assuming I'd still need to add the can of ZDDP with the synthetic as well? (Now roping this all back in to the original post) Will I see cooler oil temps with the synthetic? Quote Link to comment Share on other sites More sharing options...
johnc Posted August 12, 2009 Share Posted August 12, 2009 A fan is basically useless on an engine oil cooler installed in a road race car. If your not moving you're not generating enough BTUs to require oil cooling. Just make sure the cooler gets a lot of airflow at speed. You should not see any appreciable change in oil temps by switching oils although a switch to a lower viscocity oil might see a temp drop from the oil pump having to not work as hard. A 10W-30 synthetic oil would be my choice. If you're seeing 250F going into the cooler you're fine. I prefer Redline synthetic but Mobil 1 is good and handles moisture a bit better then Redline. I wouldn't bother with the Zinc additive. Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted August 12, 2009 Author Share Posted August 12, 2009 A fan is basically useless on an engine oil cooler installed in a road race car. If your not moving you're not generating enough BTUs to require oil cooling. Just make sure the cooler gets a lot of airflow at speed. My sentiments exactly. So, you're saying that there's no need for the zinc when running synthetic oil? However, you "would" recommend it for dino oil? I've got an old old old Racer Brown cam in the motor that I really don't want to tear up. Quote Link to comment Share on other sites More sharing options...
johnc Posted August 12, 2009 Share Posted August 12, 2009 I'm not an engine builder so the opinions of Grumpy and BRAAP should carry more weight then anything I say. IMHO... the Zinc issues are mostly related to flat tappet cam engines and are not a problem in OHC engines like our L6. Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted August 12, 2009 Share Posted August 12, 2009 From my experiences, 300 degrees pan temperature is where you should expect things to start going south. Quote Link to comment Share on other sites More sharing options...
280zNHChris Posted August 12, 2009 Share Posted August 12, 2009 When I outgas old valve covers before I powdercoat them, the oil starts to "burn" at 340. Up until 300 or so it just thins out more. Quote Link to comment Share on other sites More sharing options...
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