Oil for Hillclimbing R5 GTT

[dalla]

Hi Guys

I realise that this might have been asked before.
But I tried the searc, and were not able to find anything.
My, new to me, R5 GTT is needing an oil change.
The car is a Hill Climb race car, running slightly higher boost.
Engine seems to be in good condition, and I want to give it the best protection possible.

Can anyone advise what oil to use? Also what quantities does the GTT use?

Kind regards
Dennis

[Ian S]

In Feb 2004 I wrote this out regarding the Mobil1 0W40.

https://www.rtoc.org/boards/showthrea...should-be-used

That was 13 years ago, so I would expect some oils to have improved a bit since then.

If you're hill climbing, do you idle the engine up to full temperature before starting your run, or start the run with it cold?

There were probably better oils 13 years ago for specialist purposes like these, hence that reference to Mutol oil. Alas, those links are not working now.

[Matt Cole]

Worth seeing what Russell T uses in Doris? That car gets hammered so I guess his oil is decent enough.

I always go for something with a high zinc content or additive. Valvoline VR1 10/60 springs to mind as a decent semi synthetic suitable for a 1950s engine!!

[Ian S]

Matt, what is the advantage of adding Zinc?

I've personally compared polyolefin 0W60 and polyolefin 0W40 and the difference instantly very obvious with the higher boosted turbo'd C1J engine.

Some people would not be able to discern if they had glue in their engine, it's all the same to them, but for those with a higher cognitive performance who's neurology allows then to feel and appreciate the subtleties, there are better choices that cheap thick oil.

Then there's the problem with oil burning onto the turbo bearing casing. The 10W40 mineral oil I had from Renault for 20,000 miles, plus whatever went in there before I got the car at 55,000 miles, had baked hard into oil ways and bearings, eventually jamming the shaft. Didn't look like that was happening with the Mobil1 but only used it for maybe 10,000 miles.

As far as 'hammering' the engine, my car lived at 7500rpm. Pedal to the metal all the time. Russell's sprints are what, 1 minute? It was 15 minutes of the same pushing, or harder, to my pals along lanes, or wherever I go. The engine gets hotter and was used harder and at 24psi it was making some power as well.

And it was my 'daily driver'. So I'm starting it and pushing off from cold and I don't want to be waiting 15 minutes of gentle running for the oil to thin and the engine to start to perform, I would want it NOW. That's where the wear can mostly happen. But with Mobil1 0W40, for the first time ever, I got the performance NOW.

I have Mobil1 0W40 in my Fiat 1.1 litre and seems just as smooth and to pull just the same from cold as fully hot. Then main difference with the C1J was with the turbo spinning I expect.

As far as 1950's engines go, it's been said many times about leaking past seals, etc, 40 rated is 40 rated. Renault fitted 10W40 from new in these cars, not 15W50. If the engine or turbo is worn and you're using a 50 or 60 as a bodge then that's your choice.

IIRC, lorries do 100,000 miles between oil changes as they don't use crappy oil full of viscosity enhancers that break down after a few thousand miles. Decent semi synth is not decent if it has viscosity enhancers, which it will if it not a 0W rating. Viscosity enhancers make cheap unsuitable oil just about usable for a few thousand miles until they fail.

[dalla]

Worth seeing what Russell T uses in Doris? That car gets hammered so I guess his oil is decent enough.

I always go for something with a high zinc content or additive. Valvoline VR1 10/60 springs to mind as a decent semi synthetic suitable for a 1950s engine!!

Yeah I guess zinc content might be a good thing. It will most likely be idling to operation temp before staging.

[dalla]

Thanks for your help so far guys.

[RussellT]

For what it's worth I use Castrol Magnatec 15/40. Too thin an oil and the engine will pull it through the turbo. I hope you have fun have you any in car video?
All the best Russell

[Alex]

A quality 10w 60 for a race/track day car I used to run 10w 40 and found the oil pressure dropping off badly and the temp rising, probably as a consequence. I'm now using Castrol Edge 10w 60.

[dalla]

Thanks Guys

I Think i Will go for a good 10w60. Anyone know the oil quantity in the R5 GTT?

Also am doing my license on the 7th of April, that will be the first time used in anger. So no in car videos yet.

[Alex]

3.7 litres springs to mind? The Castrol Edge is 4L and that fills mine with a smidge left over.

Please let us know how you get on and take some pics!

[Ian S]

10w 60 for a race/track day car

I never had that with extended periods of hard road use. I fitted an oil temp sensor in the sump because I was concerned at the temp in the summer under those conditions. It would reach at about 120°C, if I recall correctly. I seem to recall that people who knew stuff saying that was OK, but not much higher.

If it's getter hotter than that when lapping a circuit under a higher % of full throttle then I agree with you that a thicker oil has to be fitted. Or maybe it need more effective oil cooler in case the oil is being over heated, if that's possible.

That's not going to happen on a 1 minute sprint, much of which is braking or cornering on a light throttle. Especially if there there are no long straights.

3.7 litres springs to mind? The Castrol Edge is 4L and that fills mine with a smidgen left over.

Me also, I would tip the whole 4 litres in. Don't know if that was ideal, just didn't want to have a nearly empty bottle on a shelf. If you don't have a baffled sump it will slosh up one end on hard cornering.

[Alex]

I never had that with extended periods of hard road use. I fitted an oil temp sensor in the sump because I was concerned at the temp in the summer under those conditions. It would reach at about 120°C, if I recall correctly. I seem to recall that people who knew stuff saying that was OK, but not much higher.

If it's getter hotter than that when lapping a circuit under a higher % of full throttle then I agree with you that a thicker oil has to be fitted. Or maybe it need more effective oil cooler in case the oil is being over heated, if that's possible.

That's not going to happen on a 1 minute sprint, much of which is braking or cornering on a light throttle. Especially if there there are no long straights.

Me also, I would tip the whole 4 litres in. Don't know if that was ideal, just didn't want to have a nearly empty bottle on a shelf. If you don't have a baffled sump it will slosh up one end on hard cornering.

You won't have that issue, even with hard road use, I didn't either. On track is a different story altogether. I agree - about 120c is about the limit from what I've read/heard. Mine was going beyond that until I fitted an external oil cooler but the pressure was still dropping off.

I agree a thicker oil isn't needed if not doing track days but a lot of people are now sticking in a 50 or 60 grade as they find oil pressure better overall.

Road car - 10w 40 is fine
Track day car - 10w 60 is the way to go from my findings

[Ian S]

They should make the rating mean something, so instead of 10W 40 call it 80W 40, and instead of 0W40 call it 50W 40, or whatever they actually are on the same scale, but at the two temperatures.