Lubricant choice

[davefiddes]

I'm getting to the point where I need to fill up my engine and gearbox with the appropriate flavour of oil(s). Does anyone have any advice on which brand/type of oil works best and/or which are best avoided?

My American Speed installation notes specify 15w-40 semi-synthetic and the Ultima manual specifies 75/90 semi-synthetic for the gearbox. These don't seem to be too common specs...

[USCANAM]

Dave
We're using Mobil 1 in the engine, 5 quarts of 10-30, and 4 quarts of 15-50. Oil cooler and remote oil filter take the extra oil.
In the gearbox we're using 1 gallon of Red Line "Red". Once again because of the gearbox pump, filter and cooler, it takes an extra quart.
All measurements are American.
3500 miles and all is well with the engine and gearbox.
I've heard complaints about the higher cost of the Mobil 1 and Red Line, but the extra cost is probably only equal to the cost of a fill-up of petrol, so --what the hell!!
I should add that since I built the engine, and the first to start it,I was able to run it the first 200 miles on a good grade of straight 30 weight oil, which is supposed to let the rings seat faster than having the added lubrication of a synthetic. Changing the oil and filter early gets rid of wearing-in metal that accumulates in the oil.
A magnetic oil drain plug is a "must" also for catching machining debris that got past the block washing process.

Jack

>> Edited by USCANAM on Saturday 2nd August 20:04

[jschwartz]

I'm using Mobil 1 oil, 15w50 in the LS6 engine
and Mobil 1 GL5 gear lube in the G50/52.
jeff

[gtrclive]

On the gearbox side of things, the Factory recomend Semi-Synthetic, More than one Ultima has had wear problems with Fully-Synthetic Gear oil. Redline has also been put on the DO NOT use list. This is a Piece of good advice please take it as I didn't know at the time, and it has cost me over 1K for a gearbox rebuild. I used Mobile 1 75-90 Gear oil. Now am using Semi-Syn Commer. So far so good. Think it is somthing to do with the loads and Heat generated by The V8s.
We all learn by our mistakes, but it's cheaper when we learn by other people's.

[USCANAM]

gtrclive said:

On the gearbox side of things, the Factory recomend Semi-Synthetic, More than one Ultima has had wear problems with Fully-Synthetic Gear oil. Redline has also been put on the DO NOT use list.

Clive
I think I remember in the past you said something about a ring and pinion burning up.
I'm going to pass this thread on to Power Haus II who built my box, and see what their comments are. I'll also try to find out what their racing customers are using.
Jack

[davefiddes]

Thanks for the replies guys.

I was wondering about using Mobil 1 eventually. It certainly seems to do a good job in the other cars I've met that run it (none big old iron V8s). American Speed have dire warnings about not using fully synthetics until the engine has done at least 3-4k miles though. Any suggestions for UK available brands? (bit surprised I didn't start a religious war asking this question before - it must be the summer heat )

Thanks for the warning about fully synth in the gearbox Clive. Sounds like an expensive mistake . I remember reading in Stigs build diary that the Factory had changed the oil in his gearbox but I'd assumed it was something to do with the slipperiness needed to keep the LSD happy. I'll bet that the LSD additives you get to tune the LSD are a complete no no as well???

[USCANAM]

Received this email from Power Haus II in regards to lubrication for the G50 gearbox;
- - - - - - - - - - - - - - - - - - - - - - - - - - -
Jack,
The factory recommends 3.8L Multigrade transmission oil SAE 75W90 of API classification GL5. I believe however now they say to use 90W only. Standard Redline 75W90 is not for use with brass synchronizers but the Redline Shockproof is okay.
- - - - - - - - - - - - - - - - - - - - - - - - - - -
Just a little bit more info on the matter.
FWIW, the Redline Red Shockproof is what I'm using, and seems fine at 3700 miles.
Jack

[Stig]

All good advice about the gearbox side of things, but have to disagree on the use of Mobil 1 for the engine. I use Valvoline racing 20W-50. I've had various V8's in the past and they all seem to do better with a thicker oil. I've found Mobil to be too thin especially when hot, giving premature wear.

[USCANAM]

Stig said:

I've found Mobil to be too thin especially when hot, giving premature wear.

Chris
Oil is a very slippery subject, and I personally won't recommend an oil, rather I'd just pass on my experiences and let the listener make his or her decision.
I use Mobil 1 in all my vehicles, but not necessarily the weight that's recommended.
I'm sure you're aware that GM will void the warranty in a C5 Corvette engine if you don't use Mobil 1. They recommend 5W-30. In the summer, I usually put in a quart of 15-50 in mine and my wifes C5.
I've got 110,000 miles on my tow van, about half of that mileage is towing, and with Mobil 1, I only change the oil every 10,000 miles. I have a rather large trailer for the van, and it's working when towing.
I used 15W-50 in the Cobra when I was racing it, and after 3 years and almost 5000 miles (the car was driven about 2500 miles on the road before it hit the track), when I freshened the engine, was amazed at the lack of wear. Cylinders and rings were still perfect, and I only changed the bearings because the engine was apart. Could not measure any wear on them, and this was an engine that spent most of it time hitting the rev limiter at 6500 rpm.
I use the same oil in the F2000 now, and see the oil most of the time going past 265'.
As stated in a previous post, I'm using a mixture of Mobil 1 weights, and presuure is constant at about 52 lbs. in the Canam even when hot and in traffic conditions.
I've had good success with the oil, the only drawback being the high cost. In the past here, we've had stores having a sale on the oil at $4.00 a quart, and I'll load up with a years supply.
Having said all this, I'm not locked in to Mobil 1, and am about to start checking into the new Castrol Syntex that's out.
Jack

[davefiddes]

Hope nobody minds me resurrecting this old thread.

Came across in a interesting study on synthetic oils and their longevity just now.

http://neptune.spacebears.com/cars/stories/oil-life.html

Their test mule is an LS1 powered Camaro so the results are not necessarily comparable to our cars (except Jeff and Mark) but it certainly makes for interesting reading. Wonder if I'm brave enough to go for a frequent filter change and top up and only change oil every 10k miles...?

[Steve_D]

davefiddes said:

..... Wonder if I'm brave enough to go for a frequent filter change and top up and only change oil every 10k miles...?

Their first trial went to 18K so why not.
I have seen info on other trials which seemed to be coming to the same conclusions.
Steve

[andycanam]

I use kendal in my Ultima.... it will be a slightly diferent grade to most as I am running solid roller lifters so I don't need it as thick.

Having stripped the engine down at 3000 miles for an inspection there was no ear at all so I am happy.

I stopped using Mobile 1 many years ago in my cossie because it became too runny over here. There of cause may be a difference in UK and US spec for Mobile 1.
However if it was to runny for my 2litre 25psi turbo lump there is no way I'd use it in my raw chevy lump.

The gearbox oil is a touchy subject.... and I am not even sure if there is a need for different oil in different versions.
I fitted what the factory recomend and havn't had a problem. I intend to use the stuff that the race boys use when I do my next oil change but it is really expensive.

[bigmack]

Assuming you don't have an LS1 or equivelent motor, I think its a bit of good advice to allow for a proper break-in of the rings and cylinder walls with a standard, non-detergent, non-synthetic, motor oil for the first 2000-3000 miles. Then you can switch to a synthetic if you like.
As for gear oil, a lot of the Porsche guys here in the states really swear buy the Swepco 201 which is offered in either a 80/90 synthetic or a straight 90 www.swepcousa.com/lubesite/products/h201.htm
Cheers!
-Mack

[bigmack]

Sorry...did a bit of research and discovered that the Swepco 201 80w90 isn't a synthetic.
Cheers!
-Mack

[bluesatin]

I have done avove 10K in my ultima and Swepco works fine as does Penrite 20/50.

[GTRClive]

bluesatin said:

I have done avove 10K in my ultima and Swepco works fine as does Penrite 20/50.

What gearbox oil do you use Guy ? and do you know it's exact name ?

[B1 ECC]

I used redline 75/90 when the box suffered a ring & piniom failure, in the second box I used Miller 75/90 semi-synthetic, to date, no problems

[tony.h]

I used to bed in and dyno an engine on a mineral oil such as Valvoline then swap to synthetic, Mobil 1 for track work. Fully replaced after every two races. about 100 miles.

15W-50 for engine
GL5 for Box (Hewland not Porsche)

[bluesatin]

Clive

The gearbox oil is Swepco. Most Porsche specialists stock it and recomend it. It feels lick it cushions the gear on change!

[Stig]

bluesatin said:

I have done avove 10K in my ultima and Swepco works fine as does Penrite 20/50.

If you don't mind bellowing black clouds of soot coming out of the 'zorts