The Cal-look Lounge

Oil's always a hot topic with air cooled engines - I'm interested to know what everyone runs (brand and grade) in their big motors and what sort of oil temperatures they see.

2180 - 9.5cr, all factory tin, stock Type 1 cooler and 1.5qt sump w/ remote filter

Brad Penn 10W30

Oil temps rarely exceed 215*F in the summer.

Brad Penn 15W40
2165cc 9.4:1

180F

lucas racing 20w50

2386cc  10.7:1

180-190F  ish

1776. 130hp. 9.5 CR . All factory tin, adjusted for perfect fit. Full flow, oil temp sender in filter head. 190-210F max even when giving it some stick!

Oh. I forgot - SAE30 ..... :-)

5-50W and 5W-60 fully synthetics only (mobil, gulf, neste) in my various engines, 100-110c (~230F). From 1955cc 8,5:1 to 2274cc 10,3:1. All of them with factory tin, dh-cooler. Biggest engine with T4 cooler, 911 piston squirters, GB sump, added 18-row cooler, PCV etc in endurance race use.

Liquimoly 5w40 Synthoil Premium. The faster I go the hotter it gets. If I get on the gas I can watch the oil gauge needle rise with the under decklid turbo and it will go to 250 F and keep rising. The single Setrab isn't cutting it so I'm going to add a second one in the opposite rear wheel arch, hopefully this year.

Not sure that oil works well with flat tappet cam and lifters. I used to sell a lot of that oil, but for newer BMW, VW, MBZ. Just FYI.

Mmmm. The only reason I use it is because it's German and my builder reco'd it. They also make Ceratec which is an oil additive that is supposed to coat metal parts, although I haven't tried it yet. I was thinking of the lifters as a newer version of zinc. http://www.liqui-moly.de/liquimoly/produktdb.nsf/id/en_3721.html?Opendocument&land=GB&voilalang=e&voiladb=web.nsf

I also tried the Liqui Moly 10w60 in my engine. When temps rose drastically on the highway going fast, I could see a difference at the point of starting to lose oil pressure due to thinning of the oil because of the high temps. At around 250 F the pressure would start dropping around 10 psi and I slowed the car down to let it cool off. The 10w60 noticeably helped but obviously more of an oil cooler is the proper answer.

I`m going to put my head on the butcher bench...

What will oil temperatures up to 250F - 120C do with our engine clearences? I strive to keep the oil temperature at max 175F - 80C on my engines as I thought that above that temperature things start expand, especially if you have a mag case. My oil is a fully syntetic, tripple ester Millers CFS 10-60.

Best rgs
BB

 

Steve told me that high temps are hard on the bearings. The oil temp is the case temp. The head temps are a different issue and can cause heads warping and studs pulling, seats moving and head related problems. Clearances shouldn't change though.

2332 - 11.5cr, 200bhp+. 30hp tin / adjusted for fit, Berg 4 quart sump
with remote filter and 19 row Mocal remote oil cooler with electric fan,– controlled by Scat in line thermostat switch.

Valvoline 20w50 vr1 racing oil

Oil temps winter cruising at 65 mph  around 80c or 176f
Oil temps summer cruising at 65mph around 90c or 194f
Oil temps winter when spanking it hard - max 95c or 203f
Oil temps summer when spanking it hard - max 110c or 230f

On long turns, our endurance car's oil temp sensor location on type3's oil filler plate sometimes gets over the oil level. The temperature of the air inside case is higher than oil - it immediatelly rises from the 100c oil temp up to 150c "air temp" inside case.

Although bearing temp should be just about the same than oil temp + (hopefully very) small temp increase from friction.

Thermal expansion in metals are linear to temperature, or at least in this kind of temperatures and materials. I suppose this thought has something to do with thermal expansions of different materials (case, bearings, crank etc) and that in higher temperatures, it decreases or increases tolerances too much over some temperature. Or then it may have something to do with heat stress affecting / warping the case. Interesting topic even if I'm happy with 110c oils in measured from type3 filler plate, piston squirters tend to increase oil temp inside case.

I suppose that isn't air inside the case, it's probably closer to exhaust (blowby) and very hot!

That may be true as the engine breathes quite hard now, maybe pistons are already a bit warped after hours of abuse. But I suppose there is always some blowby so it would be natural if the air inside case should be at least a bit warmer than oil temp?

Your engines may benefit from crankcase vacuuming. Either a pump or a passive exhaust powered system.

Yep, for this summer, exhaust based PCV is already in the making, just missing a few AN joints to complete piping from the oil separator tank. In the same time we're going to transfer the oil temp measurement into the main oil galley to determine the temp of oil going into bearings, not the oil temp on the case just before it's going to be cooled again. We had also external vacuum pump from an LT diesel engine but we soon found out that it wasn't worth the hassle.

This was our experiment:
http://img.photobucket.com/albums/v415/mschilling/IMG_2957.jpg

5W40 LiquiMoly synthetic and Joe Gibbs 5W40 synthetic in my 2332 cc engine, 10:1 CR.  Still have the original bearings after 600+ trips down the drag strip and 48,000 km.  Using the OEM '75 FI doghouse cooling system with velocity ring and all OEM engine tin.  MS230 heads and Mahle piston/cylinders.

Oil temperatures are 80-90°C. during continuous driving and infrequently reach 95° C. (on hot summer days of 30°+ C.).

I can get the oil to reach 100-105° C. when hot lapping at the drag strip ;)


 

30HD Castrol or Valvoline with Cam-Shield additive ... been using with great results for the last 2+ years in my 10.5:1 2276 and all my air-cooled customers engines.
My temps run 180-190 in summer, a bit over when it's run HARD. ;)
TxT