What Engine Oil To Use?

[JONES OFF ROAD]

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

[icingdeath88]

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.

[Hondasucks]

Originally Posted by JONES OFF ROAD

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

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

[svxistentialist]

Originally Posted by JONES OFF ROAD

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

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

[benebob]

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.

[JONES OFF ROAD]

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!

[oab_au]

Originally Posted by JONES OFF ROAD

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!

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.

[RallyBob]

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.

[dynomatt]

Steve,

Reviving an old thread, but how'd you go with the oil?

Do you run oil temp and pressure gauges? What did you see?

Thanks,

M

[JONES OFF ROAD]

I race next weekend 24-25th, using the lucas full synthetic.
I dont run oil temp/pressure guages, just wait for the knocking noises then stop
Whats wrong with fram oil filters? I am actually using one!

[Nevin]

I've seen too many motors destroyed because they used Fram filters. A buddy of mine worked at an audi dealer and in 1 year they replaced 3 motors in different cars and they traced them all to the oil filter... Fram.

They filter really well, but the problem is that they filter TOO well and drop pressure. Now, on motors that run higher pressure like ours its not as huge of a deal, but when a motor is run hard it just starves the bearings for oil.

I can think of a few other people who had similar experiences and ruined motors because of Fram filters.

A buddy of mine went to school at a nationally known mechanic school (UTI) and even one of his instructors told the class that he was at Wal-Mart one time and had to get a filter. It was between Fram and WalMarts own brand, and he bought the WalMart filter. He told the class to avoid Fram filters at all costs.

[Pierre-Olivier]

I used a MOTUL 300V 10W40 for my SVX.