What Engine Oil To Use?
 

Gday All,
Now that I dont have an overheating engine, I am getting the buggy ready for racing again.
The next race will be 700km long, non-stop (except refuel) with an average speed of 120km/h, and my engine running over 6000rpm for 90% of the race.
What oil viscosity do people suggest?
Obviously I will use full synthetic, but should I use a straight or variable grade, if so, what grade?
Ambient temp should be about 25 deg celsius, engine temp should be around 85 deg c, and engine is in stock form.
I am a bit worried the engine might not stay together under these conditions, and would like to gear-up for less rpm, but that will sacrifice acceleration, which I am already 40-50 whp down on the nissans and toyota engines....so I guess I will just hope for the best!!!
Thanks, Steve

Re: What Engine Oil To Use?
 

Aww, you got me all excited for nothing. I was thinking "Oil recommendation? Yay, finally a question even I can answer!" But all this talk of racing and buggies means I'm once again out of my league... Ah well.

Re: What Engine Oil To Use?
 

I'd use either 10W-30 or 20W-50 synthetic, I wouldn't go with a single-weight oil.

Re: What Engine Oil To Use?
 

Steve

The best of luck in the race. I hope for two things really, that the cooling gremlin is in fact licked and your engine runs the distance to prove this, plus naturally that your engine holds together on the mechanical level. Make sure your tensioners are good and you have a decent cam belt. Running those high revs will seek out any weaknesses.

Subaru Owners' Manual recommends API grades of SF and SG. These are old grades and I think only SG is now in use, modern synthetics have gone far beyond these capabilities.

The manual also cautions against using 5W-30 for sustained high speed driving, so this flags a potential problem for you. 30 is not good enough for the heat

Steve if I was undertaking your race I would use Mobil 1 15W-50. It is expensive and it might seem a bit like overkill, but you will need the viscosity that the higher number will give you.

As I said, best of luck mate.

Joe :)

Re: What Engine Oil To Use?
 

Personally, I would go with a 20w-50 Valvoline Race Oil (not a syth). Made for race engines, cheap enough to change after every race or two and call it good. Sythetics thrive at lower temps and overheating temps. 2 areas you shouldn't be running a race engine at to begin with.

Re: What Engine Oil To Use?
 

Thanks for the replies,
As Joe said, most API grades are well above the old standards now and are not really an issue.
I used to run full synthetic, then dropped back to a mineral oil for the reasons benebob suggests....just thought I might spoil her (the engine that is) for this event and run full or semi-synthetic!
I was actually thinking a 20-50w? But had thoughts of a straight 40 or 50w?
BTW, cam belt is new and all tensioner bearings etc checked/repacked.

I just havn't had the chance to run these EG33's under full race conditions due to the overheating, therefore have not been able to get an idea of the mechanical reliability, so I need to build some confidence in these engines....also it will need to be treated a LOT harsher than other engines in my class due to lack of power compared to the 3.5 nissans and toyotas (we are limited to 3.5ltr N/A)
Heres Hoping!

Re: What Engine Oil To Use?
 

Steve I wouldn't run a straight 40 or 50. When it is cold there is a chance that you will break the pump rota. This is the same pump as the Nissan RB 3lt engines had. We had one break, running in a fresh engine using 40 wt. I'd use a Mobil 1, as Joe suggests. Its cheaper than an engine.

Harvey.

Re: What Engine Oil To Use?
 

We were running either Valvoline 20w-50 racing oil or Brad Penn 20w-50 racing oil in Jack's EG33. I think Motul would be even better, but it was out of the budget considering the frequency of oil changes in a race car.

Mobil 1 and Amsoil didn't cut it for Jack's Impreza...oil pressure dropped way off when hot.

Re: What Engine Oil To Use?
 

That's kind of what I would think. Just from putting it into my wifes car and taking it out warm. It flows like the TVR oil I just emptied with an extra quart of gas in it from a leaky injector. Granted modern engines are made to run with this water in there, the SVX motor isn't a modern engine in that from factory it doesn't recommend and of the 5w-30s or the like for long distance driving. Not that I think it would blow anything up, I just don't think the cost of it is worth it over the lifetime of a race engine and oil changes after every race or every couple months from sitting idle.

Re: What Engine Oil To Use?
 

If I may offer up some of my experiences with Track days and Autoocrossing and oil...

The oil I used to run in the STi (and the only thing that had been in the engine since it was new) was Motul 300v (15w-50)

http://www.turnermotorsport.com/imag..._2_liter_1.jpg

However it is rather pricy and does not contain "detergents" to help keep gunk from building up. It is AWESOME for race engines that change the oil frequently, absolutely stellar heat resistance, and it actually smells like bubble gum (Ester based)... If you look up the research on it, as far as an oil goes you really can't beat it... But all that comes at a cost... ~$32 / 2 qt can... So after a year of multiple $100+ oil changes, I finally switched over to....

Amsoil Synthetic 10w-40

http://www.syntheticwerks.com/Feature/zinc_ad894b.jpg

So far I have noticed that my oil temps are marginally higher on average (MAYBE by a few degrees) and my oil pressure is about 10 psi lower at idle than it was with the Motul (~25psi vs 35+psi)... It is a good 2x cheaper than the Motul though so I am alright with that, especially considering I ran one 1,500 mile change of Castrol Synthetic through the engine before switching to Amsoil and BOY that was a change... It didn't deal with the heat at all and I constantly saw temps between 210 and 230!! Driving aggressively I saw temps above 230, and I didn't like that at all (not something you see with the Motul unless you are thrashing it for 15+ minutes straight - ie. on track)

Moral of the story?

Well the Amsoil works just fine for me right now on my current budget. It has detergents in it to keep the engine clean and gunk free, it is from a company that was first in synthetic oils, so there is history... However when it comes to all out performance, I haven't seen anything beat the Motul... It's just $$$$... BUT, you definitely get what you pay for :)

~ Chris

Re: What Engine Oil To Use?
 

FWIW, I've found that Redline sort of fills in the gaps below the Motul's performance levels. Works much better than the Amsoil and Mobil 1 in regards to maintaining hot oil pressure and keeping the temps low. Not as nice as the Motul but very good for the money.

Re: What Engine Oil To Use?
 

What do you guys think of Royal Purple? :rolleyes:

Re: What Engine Oil To Use?
 

Royal Purple, Amosol, and Redline refuse to allow their products to be independently verified. If you look on their bottles it does not say this motor oil meets or exceeds Motorcraft (bunch of numbers and letters, GM (ditto) etc... For that reason I would never put them in a car I cared about. They claim I'd guess that it is part of their "secret recipe".

Re: What Engine Oil To Use?
 

10/60 TWS Castrol... Its all I will run in the M5 which was built for the Ring and the Bahn.... High revs on AL bearings. Pricey at $125 for 7 liters but... makes the the crank go round and round again

http://www.velocitymotorcars.com/com...62-engine.html

Granted ur gonna get an e39 filter w/ it but hell, best price anywhere

Tom

Re: What Engine Oil To Use?
 

Hmmmm, I might have to do some research and see where I can get some of this "Redline" you speak of :p...

~ Chris