Oil choices for 240Z race car

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Hopewell Junction, NY
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Hi everyone! Little background: My Dad and I have a vintage race shop which takes care of primarily British vintage race cars, but I just bought myself a Datsun 240Z to hopefully have fun with now and then. It's a little out of our regular wheelhouse and I'm trying to be careful not to assume things about the Datsun based on my British experience. Engine oil is one of those things. We use Royal Purple 20W-50XPR in everything else and it's worked very well (though I wonder if there's anything lighter we could use in there...), but I'm not going assume it's good for the Datsun because of that. I'm happy to provide specifics of the Nissan L24 engine if that would help, but this car is used for vintage road racing and as such sees 7,000rpm regularly. First off, I've taken some time to attempt due diligence and avoid starting a new thread. I wasn't able to find much experience with the specific oils shared with me, so I'm going to address them directly. After talking with someone who has a lot of experience and asking which oils are good choices for this engine, I was given a short list: Amsoil AMO/Premium Protection 10W-40 Joe Gibbs 10W-40 Motul 300V 10W-40 Rotella T6 5W-40 I know how good Amsoil products generally are, and I know 300V is popular with bikes at least, and that Rotella has a sterling reputation for flat tappet folks. I'd lean towards the Rotella for myself because it's significantly less expensive than everything else, and it appears to still have sufficient additives for an engine like the L24, but I couldn't find much about anyone using the oil for racing. Does anyone have experience racing any of these oils, or a link to info of that sort? Thanks! Mike
 
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Originally Posted by Powerglide
My 280z seems to like Mobil One HM Full Synthetic. But it's a completely stock Fuel Injected car with only a header and free flow exhaust.
Thanks for replying! I've seen and heard of Mobil 1 oils becoming very thin under race conditions, so I'm going to stick to one of the four oils listed above for the time being. That being said, I use Mobil 1 0W-40 in my BMW E30 street car and love that stuff in a road context.
 
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Originally Posted by michaelsvintage
Originally Posted by Powerglide
My 280z seems to like Mobil One HM Full Synthetic. But it's a completely stock Fuel Injected car with only a header and free flow exhaust.
Thanks for replying! I've seen and heard of Mobil 1 oils becoming very thin under race conditions, so I'm going to stick to one of the four oils listed above for the time being. .
Mobil1 15w-50.
 
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Hopewell Junction, NY
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Originally Posted by Chris142
Originally Posted by michaelsvintage
Originally Posted by Powerglide
My 280z seems to like Mobil One HM Full Synthetic. But it's a completely stock Fuel Injected car with only a header and free flow exhaust.
Thanks for replying! I've seen and heard of Mobil 1 oils becoming very thin under race conditions, so I'm going to stick to one of the four oils listed above for the time being. .
Mobil1 15w-50.
That is a good oil, but I was told 50-weight is too think for this application.
 
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Originally Posted by michaelsvintage
Originally Posted by sloinker
I'll read up on it. I see the site is in German; how's price and availability in the U.S.?
Blauparts.com This is the U.S. seller located in Wisconsin. Wait for their sales as it isn't the cheapest available, on a par with Amsoil price wise. The oil with PAO/Ester base is licensed in many grades for many applications, even the racing grades. If it has Group III it will be noted as a HC grade and you won't be paying extra for a less expensive base oil. Read the descriptions carefully as they have many formulations available that differ only slightly from one another. The grades with Clean Synto and USVO are PAO/Ester base oils and will note any add pack that is unique.
 
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Alright, it's good to be getting some suggestions. Does anyone have racing experience or knowledge with any of the four oils I mentioned, specifically the Rotella which isn't "branded" as a performance oil?
 
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Rotella isn't usually associated with racing but has billions of observable miles and many many satisfied users in the trucking industry. Try it and run some UOA's and see how it performs. Maybe add an oil temp gauge to monitor when racing.
 
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Hopewell Junction, NY
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Originally Posted by sloinker
Rotella isn't usually associated with racing but has billions of observable miles and many many satisfied users in the trucking industry. Try it and run some UOA's and see how it performs. Maybe add an oil temp gauge to monitor when racing.
Alright, I'll give it a go. I'll be running oil temp, water temp, and oil pressure gauges so I'll keep a close eye on that. I haven't done it before; what do you think a good interval to get useable UOA data from a race engine would be? One race weekend is about an hour to an hour and a half of race time.
 
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If you spend a lot of time at high RPM's and/or have a lot of fuel dilution, dont use Rotella. The Joe Gibbs or the 300V would be my choice. Have done lots of work on track cars with flat tappets (M20 BMW's) and there was noticeably more cam wear/rocker arm wear with the dino/cheaper oils than the dedicated race oils. Power drops off quick with valvetrain wear.
 
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Originally Posted by Renzo
If you spend a lot of time at high RPM's and/or have a lot of fuel dilution, dont use Rotella. The Joe Gibbs or the 300V would be my choice. Have done lots of work on track cars with flat tappets (M20 BMW's) and there was noticeably more cam wear/rocker arm wear with the dino/cheaper oils than the dedicated race oils. Power drops off quick with valvetrain wear.
Very helpful input, thanks! I actually daily an E30 325i and came here for opinions on oil options for that years ago. Settled on Mobil 1 0W-40 which I've been extremely happy with.
 
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The first 3 oils in your list are good for high-performance gasoline engines. I wouldn't use RT6 in this application. Its later formulation has decreased zddp content, which is detrimental to valvetrain wear. I would add Redline 40WT to the list, but the Joe Gibbs 10w40 would be my favorite. Does your engine have sliding cam followers? What are the valve spring load specs? Max valve lift? Does the oil system have a cooler in it? How about an accusump? Wet sump or dry sump oiling? Total volume of oil in the system? Once upon a time, I crewed for a Nissan 240SX race car in the 24 hours of Daytona (1996). It was a tube-frame car that had a 240Z engine in it, but a 240SX fiberglass body. I don't remember what oil they ran in it, but I might be able to find out if you're curious.
 
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Hopewell Junction, NY
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Originally Posted by A_Harman
The first 3 oils in your list are good for high-performance gasoline engines. I wouldn't use RT6 in this application. Its later formulation has decreased zddp content, which is detrimental to valvetrain wear. I would add Redline 40WT to the list, but the Joe Gibbs 10w40 would be my favorite. Does your engine have sliding cam followers? What are the valve spring load specs? Max valve lift? Does the oil system have a cooler in it? How about an accusump? Wet sump or dry sump oiling? Total volume of oil in the system? Once upon a time, I crewed for a Nissan 240SX race car in the 24 hours of Daytona (1996). It was a tube-frame car that had a 240Z engine in it, but a 240SX fiberglass body. I don't remember what oil they ran in it, but I might be able to find out if you're curious.
Ah, I didn't realize they'd changed the formulation recently. That's too bad. Thank you for letting me know! Original followers, springs are 100/110lb closed and 210/230 open. Max lift is .488"/.503". No oil cooler, original wet sump setup. These cars don't experience excessive oil temp as delivered until over an hour of racing (at least according to those I've talked to, some of whom worked for BRE), which is longer than this car will be running at a time in the foreseeable future. Total volume of oil is about 5 quarts. That's very cool! That sounds like a serious piece. If nothing else, it would be interesting to know what oil they used for academic purposes.
 
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