Oils for old racing engines

[Redneck Rocket]

My friend and I were just discussing this. We've both heard that older engines are not suited to modern synthetics for a variety of reasons, but thought surely that only applies to synthetics of a lower viscosity? If a 20-50 mineral oil is suitable for an older engine, why is it(rumoured) that a 20-50 synthetic is not as good? We're also assuming this is a fresh build and that there is no residual oil of any type in the engine.

[thebear]

I am sure that the main consideration in the new oil/old engine discussion is leakage from gaskets and seals. When re-building it might be beneficial to use modern sealants and gasket material wherever possible as well as being certain of your torque wrench calibration and application.

[awseng]

we are stockist for a well known brand of oil (not naming not a sales pitch) who offer a wide range of mineral to fully synthetic oils in various viscosity.
one of the main reason that used to be the case is indeed if on oil change you put an early type synthetic oil in, it reacted differently with oil seals tending to make them shrink and go hard, as mineral oil did the opposite, this is not the case with synthetic oils today.
some of the components in synthetic oils dont have as good load bearing properties as mineral, but when blended with the other components that go into make a synthetic this out guns mineral oils. that coupled with the fact that if your 'old' engine has just had a major rebuild it will more than likely have modern made materials inside, but this does not change the loads that are produced in an old design, on the whole fully synthetic oils are more stable, better cleaning less burning better load bearing.....most engine builders who recommend a particular oil made by whoever also sell it!!! the choice is still yours!!!

[zefarelly]

I've used 3 or 4 different 20/50 semi synth oils and to be perfectly honest have never noticed any difference whatsoever !

I'd add that they've all been good quality, not recycled chip fat!

[john ruston]

All our race cars and those of my mates have changed ,(I have the odd one or two,)have changed to Motel.The gearbox specialist was amazed at the superb condition of the pre-selector box after a years racing and its the only stuff that works in the Alta and B8

[terence]

The problem started years ago when people rushed out and bought the 10/60 Oils etc;Bearing in mind they were expecting a power increase for the price of an[expensive]oil change,all they got was a lot of oil on the outside of the engine.Usually,if the engine has been built correctly,there should be no problem.personally,I use Motul,LeMans for the engine,suitable 300v in g/box and rear axle,I won,t use anything else,no need to.

[Al Weyman]

On my old design engine (Small Block Chevy circa. 1953?) I have just gone over to Lucas Racing oil 20/50 mineral and I did notice a difference, it ran cooler and maintained pressure better when hot.

[IAN #51]

I have always used Penrite 20-60 in my 1296 Spitfire but have recently tried the Lucas Racing oil 20-50 and as AL says it does maintain hot pressure better than the Penrite approx 10 psi better

[Al Weyman]

I have also filled my gearbox with their oil 80/90 interestingly they state it can be used as is in LSD's.

[zefarelly]

is the lucus 20/50 better than valvoline in you guys opinion?I can get both locally

[Al Weyman]

It was recommended to me by one of our Post historic guys and has a good pedigree in the US in NASCAR etc, you want the super dupa one I believe (name escapes me). A guy on ebay sells it and its competively priced as its in a 2 gallon jug unusually he is very easy to deal with and you can phone him direct, I think he is in birmingham and wont rip you on the delivery, I have a contact if you want it but its down the garage. I am comparing it to the Uniroyal Green which was recommeded to me but I'm not so sure and is no longer available anyhow and I would say it was definitely more stable than that and dont ask me why but it definitely ran cooler if thats possible and held hot pressure better.

[LC driver]

Originally Posted by zefarelly

is the lucus 20/50 better than valvoline in you guys opinion?I can get both locally

Only the distributor in The Netherlands wants to drive with Lucas .
I use Motul 15/50 300V competition no complains at all.

[Al Weyman]

Only the distributor in The Netherlands wants to drive with Lucas .

Why is that, has anyone actually bothered to try it?

[LC driver]

Originally Posted by Al Weyman

Why is that, has anyone actually bothered to try it?

I don't think so. Everybody seems to be happy with what they are using. I will only try other oil after a rebuild of my engine. There is no reason for me to change from Motul to Lucas. Most of the drivers in Holland are using Shell or Motul. And the distributor is driving in our series perhaps that is the reason

[esper]

Originally Posted by LC driver

I don't think so. Everybody seems to be happy with what they are using. I will only try other oil after a rebuild of my engine. There is no reason for me to change from Motul to Lucas. Most of the drivers in Holland are using Shell or Motul. And the distributor is driving in our series perhaps that is the reason

so who the ,, is that??? don't tell me you get it cheaper (typical example of dutch problems)
i wouldn't mind trying Lucas but its not available overhere. and then using 80/90 in a gearbox is typical v8 ...................................small engine guys cant affort to lose all those horses in the gearbox

[275 GTB-4]

BP Coarse Plus

[LC driver]

Originally Posted by esper

so who the ,, is that??? don't tell me you get it cheaper (typical example of dutch problems)
i wouldn't mind trying Lucas but its not available overhere. and then using 80/90 in a gearbox is typical v8 ...................................small engine guys cant affort to lose all those horses in the gearbox

Esper I think that the man in the red jaguar with the black roof in our series is the distributor here so it's available I am sure for that.