Engine Oil

[Eldert]

Jim Dour from Megacycle cams recommends Kendall and Redline straight 40 as the best oil for his camshafts .

i dont know of Kendall changed their formula after the Conoco takeover . some people say its not the same anymore

Nigel Lacey uses Silkolene 15 w 50 in his highly stressed racing engines so i would stick with the Silkolene

most oil companies are cutting back on the ZDDP levels in their oils to protect the catalytic converters but its the
ZDDP that we need to minimise wear on cams , followers , tappets and rockerarms

Eldert

[MotoMike]

thanks Eldert
I don't recall seeing silkolene products in these parts. must be a UK company.

when discussing cam protection, my mind goes to the hot rod engines (automotive) I have had a hand in building and setting up the valve trains. I think of the huge spring loads that are required to keep the big valves from floating and compare those loads to the relatively tiny valves we have in our Duc singles. even the street/strip cams, that is to say not full race would have closed valve loads of 150 pounds and open of over 400 if memory serves. I know the performance change is to switch the hair springs to coil, but are the spring pressures high in these applications? Is anyone in vintage duc racing using desmo valve gear and winning? those valve trains should be relatively easy on the cams and followers, shouldn't they?

[LaceyDucati]

Eldert is correct that I do recommend Silkolene Comp 4 in both our Road & Race engines. Although the grade we use is 20W-50, this is in fact the same Oil that Silkolene used to market as Racelube 20W-50. For many years we used Racelube 40 which was dropped from the range the early 90's and the other oil in the range, a 20W-50 was rebranded into the Comp4 range. After much consultation with the head chemist at Silkolene we decided to switch to the 20W-50 as it had the properties we required. These oils in the racelube range had been specifically designed for roller bearing engines and specifically had additives to cope with the high loads of race cams (as described by Eldert). I was also told at the time that the racelube 40 had been a replacement for shell SR40 (long since obsolete) which interestingly was the oil we used before racelube 40. These oils had been designed specifically for a race car with roller bearings. I cannot remember exactly which car, but recall it was something exotic! We tried a 450 engine for a season and experienced no problems, so we then continued the following year switching everything over to this oil. That was probably 8 years ago and still nothing to report.
The racelube oils were described as mineral oils with additives and over the years the oils have now become described as a semi synthetic with something called electro syntec technology. When quizzed about the change of description and new technology I was told the make up of the oil had not changed and it was all to do with marketing. Seems you cant sell mineral oil any more and bull***t sells! It also appears that the other grades of oil in the COMP 4 range are not the same, and anyone considering using comp 4 should stick to using the 20W-50. I am no expert on oil but I took advice from someone who knew a lot more than I did and it seems there is a lot more to oil than just grades and types. I have stripped many race engine that have run for many years on this oil and am very satisfied with my findings. I have also stripped a lot of other engine which have run on Castrol R and full synthetics and not been impressed with my findings. If you are running a road bike I am sure the classic straight 40 oils by Silkolene and Morris are perfectly adequate and there are probably other perfectly good oils out there.

For those who do not recognise Silkolene (old English manufacturer) , Silkolene is now marketed by Fuchs who took over Silkolene.
For your interest here is an extract from the Silkolene website:

COMP 4 20W-50
Particularly suitable for use with tuned racing engines or high performance units being used in hot climates. Has excellent high temperature-viscosity characteristics to help protect highly stressed components and maintain consistent oil pressure and shear stability. Also offers excellent ‘stay-in-grade’ performance and long lasting corrosion resistance, even during periods of intermittent use. Suitable for many vintage and classic engines where monograde oils were originally specified. Also ideal for larger air-cooled V-Twin engines and in roller bearing engines.

Mike - quick surf revealed this link as a US distributer http://www.silkoleneusa.com/contact.aspx

Nigel

[MotoMike]

Nigel
thanks for the link. Silkolene is still pretty rare over here. Even with the distributor in Harvey IL, I've never seen it in a store. Online is an option but with shipping over $10 a quart.