Engine Oil

[SPRINTPARTS]

As matter of interest, what type and grade of oil are people using in there Sprint "full race" motors?

The choice of oil is sometimes very personal preference particularly brand, but what really is of interest is grade and type of oil used, be it Synthetic, Semi-Synthetic, or Mineral. Climatic conditions pay a large part in grade of oil, I am still interested to see what is in use.

Thanks

Mark

[jeroensprint]

Hans uses motul and i use castrol edge sport 10w60 synthetic with an zddp additive for wear. That is not in it because it kills catalysators but i do not have it. In the US castrol has a synthetic oil for classic race engines with zddp but that is not available here in europe. The edge sport with the zddp additive is almost the same as the us classic synthetic castrol.

Jeroen

[Hans ten Broeke]

We have used full syntatic racing oil all the time with great results.
On the otherhand, just becouse an oil is a syntatic one dous not mean it is good for racing.
In general people made often the fault going to a modern type of oil (mostly with a better cleaning capicety than the previous oil) and running into trouble becouse old dirt get floating and start damaging.
A good clean in forehand is always good.
Next to that without altering bearing clearance etc etc stick to the same viscosity as recomended.

There can be much told about oil, many books are full of it, but please dont pull it into a mithe, it is simply technick, but not simple though.

Roule of thumps,
Film strengt is much better.
Desintegrating far later, it keeps over the time the viscosety better
Temperature better stabilety, so also here it keeps better the viscosety.

In the new engines I probable will go down to 5 / 30 depending if I can get the proper racing bearings.
A concern is the flow of oul to the top, and now I have the camchaft bearings under control this is a posebilety.
But as always ther have still a lot of investigation been done before, like proper presure mesuring direct in the oil galerys and rocker shaft to name some.

Hans

Hans

[Paul Roberts]

I certainly don't have the full race engine, but a mildly tuned one used in anger in motorsport events. I have always used Mobil 1 in the engines and I've never had reason to change. I'm sure I do oil changes more often than I need to, but it seems to me that an oil change after every couple of events is cheap insurance. Oil pressure is always consistently good, both at idle and full revs. The only engine problems experienced over 15 years of on and off Sprint competition, including racing, have been the standard two - block failure and head gasket failure and I don't think either of these can be blamed on the oil.

Cheers

Paul Roberts
Perth, Western Australia

[SPRINTPARTS]

Thanks for the replies so far received. The answers are sort of what I was expecting.

I have never had a problem with bearing in my motors (25+ years of racing) until recently recently which has seen several failures, for which I can't identify the reason for the failure. The oil brand and type has been the same for the last 15+ years, bearing are the same as used for the last 5+ years, but change my be coming soon. I am not blaming the oil, but I need to do something.

Hans

In the new engines I probable will go down to 5 / 30 depending if I can get the proper racing bearings.

are you prepared to divulge what you use, and supplier source for bearings?

Thanks

Mark

[Hans ten Broeke]

If it come that far,we gone sell them.

Hans

[DavePoth]

If it come that far,we gone sell them.

Hans

Should be quite a market for them if you add up all the Dolomite, TR7, Stag and early Saab 99 owners.

[gmsclassics]

Mark

I've been using Motul 300v 15-50 fully synthetic as it appears to maintain a better oil pressure in very hot conditions than anything else. I tried the Castrol Edge 10-60 once but went back to Motul after seeing lower oil pressures when the revs dropped.

Given that the crank I've been running for a number of years without incident has been ground down to the maximum limit and is fitted with ordinary bearings and shells, Motul seems to be worth the bit extra it costs.

Geoff

[Hans ten Broeke]

Till now we used this Motul 15/50 V300 with great results.
If I can if all the engine changes work out as I expect I would like to go down to 10/30 but fore sure from the V300 type.

Actualy after several years of very good results we sel qute some of it to for example the high boost Lancer guys.

Next to that, not that well known by the publick, but Motul also has a very good line of clasic oil with the Zink etc components to protect cam lobes. Normal oils dont have that animore nowadays, cat converters etc etc dont alow that, but old disign engines love it.

Hans

[Dolly racer 33]

I have tried many different oils on my car & others I have run over the last 20+ years. I have found that the best oil by far is Millers Classic sport. This is a 20/50 semi synthetic oil. I find that modern fully synthetic oils are too thin 7 during the longer races I have done I have had to overfill the car at the start or top up during the race. Remember our cars were designed for 20/50 oils.

[Hans ten Broeke]

Overfill , I wonder where that oil went.

Hans

[SPRINTPARTS]

Thank you each person for their input and information. I don't agree or disagree with any of the comment made about what grade of oil that people are using, it just shows the difference of opinions and experience that each person has had on this matter.

The answers here are similar to what I have been given locally, some people saying that I should be using modern synthetic oil (10-50w) or similar and others say using 20-60w mineral oils.

Back in the 1980's I ran a series production specification Sprint for 6 seasons (approx 8-10 meeting a year) never touching the motor except to replace the timing chain once. The motor ran on 20-50w mineral oil which was replaced every 2-3 meeting.

During the 1990's I started racing the current specification cars (approx Group 1 or 2) and never had any bearing problems. I really only ever used 2 or 3 crankshafts in all that period (nitrided) and each time the crank was removed it was just polished and fitted into the next motor. That is until recently. In the last 2 seasons I have destroyed or damaged 3 crankshafts, with 3 BE bearing failures. Nothing has changed, same oil, same brand of bearings, same machinist, and same engine builder (me, which might be the problem!!), so I am a little lost where I go from here.

About the only idea that we do have is maybe detonation, but there is so other indications apparent to us, and all other bearings in the motors are like new and could be reused if so desired.

Thanks

Mark

[trackerjack]

Hi Mark,
is it possible that the modern fuels are creating more heat or something? a bit of a shot in the dark or perhaps it is just luck, good and bad.