Synthetic oil for classic bikes

[a101960]

I have just ordered some of this. http://www.opieoils.co.uk/p-1123-silkolene-comp-4-20w-50-synthetic-ester-based-4-stroke-engine-oil-for-high-performance-motorcycles.aspx  A it is a full synthetic 20/50 oil for classic bikes. I have posted the link in case any one else is interested in using full synth oil in their bike. Silkolene have developed this oil specifically for old air cooled motorcycles. Anyway check out the link and read all about it for your self.

John

[muskrat]

 Only if you have done a full rebuild and all internal parts were cleaned. It would be the same if you switched to a diesel type oil, high in cleaning agents that clean off all the old built up crud and blocks everything up.
http://www.machinerylubrication.com/Read/28601/switch-to-synthetic
Cheers
Oh no an oil thread!!!

[A10Boy]

I was going to say don't use full synthetic for running in, I never have but apparently it glazes the bores and it will always use oil.

[bsa-bill]

I'd have no hesitation using a Synthetic in my bikes, both have however been fully cleaned internally as Musky remarked and have filters fitted.
The one factor against would be cost maybe, depends if I thought I could safely extend the change period, although fully synthetic in my rovers would last the full 12,000 between services and never needed topped up, amazing stuff (in modern engines)

[a101960]

As a follow up to this topic I thought that I should mention that I had a PM from another board member who quite rightly was worried about the ZDDP content (if any and the ratio) of Silkolene Comp 4 fully synthetic oil. This concern was very valid because it has been the habit of oil companies to steadily reduce the ZDDP content in oil in recent times, and most full synth oils do not have ZDDP in sufficient quantities (if at all) to protect the cams and followers in our type of engine. So, just to be sure I contacted OPIE OILS who I purchased my oil from and this is their response:

Hi John,

Thanks for the mail.

The Silkolene Comp4 20w-50 has plenty of ZDDP, it has around 1400 ppm and a good ester content too. It is aimed at the competition/fast road market as oils designed for sports use, so still has good levels of ZDDP, this is why it is also suited to classics and some vintage. You can also tell by the spec the oil meets, reduced levels of ZDDP started to occur with API SM spec, anything prior to that has plenty. The Comp 4 is API SL/SH.

We use this oil in a rebuilt but standard 1931 Austin 7, with gauze filter.

In short, the Comp 4 20w-50 is ideal for your 650 BSA Rocket and you can use it with confidence.

Regards

Guy

If anyone has considered using full synth oil then that information should provide some assurance. I thought that it would be good to bring this matter to your attention because not all oils are the same. Of course other full synth oils are available but it would be prudent to check out the specification before you buy. I know that you guys in Oz for example have a suitable Penrite oil for instance, but we do not have that over here. So far as I know the Comp 4 Oil is the only full synth oil on sale in the UK that is compatable with our old engines. I am sure someone will soon put me right if I am wrong in this assumption!

John

[muskrat]

 That's good info John, thanks for posting.
Cheers.

[Sparky]

And as an addendum to the above discussion, ZDDP is also available as an additive to restore or suppliment the level in whichever oil you may be using.

[Triton Thrasher]

So far as I know the Comp 4 Oil is the only full synth oil on sale in the UK that is compatable with our old engines. I am sure someone will soon put me right if I am wrong in this assumption!

John

Don't know whether right or wrong. I've been using this in another marque of British 650 twin and it doesn't seem to have destroyed the engine yet.

http://www.opieoils.co.uk/p-866-motul-300v-le-mans-20w-60-racing-engine-oil.aspx

[Rgs-Bill]

RGS-Bill here. For those of you who like the single weight mono oil with very little detergent, (so the sludge trap can work properly) , (some still do not have filters fitted on their bikes), and that is a problem when using detergent oils, the sludge trap can not work because the metal particles are in suspension in the oil, waiting for the filter to remove them, not being flung out in the sludge trap.
  There is a company called Brad Penn, who bought out the original Kendal green oil, mono weights, 30 wt, 40wt, 50wt, 70wt, this is the oil that was recommended for these bikes when they were originally built.  Very low in detergents, high viscosity index, and ZDDP ratings in the 14 to 15  Parts Per Million, to protect the followers and the case hardening also on the cam lobes.  I am not sure if it is available in the UK, but they have a website  where you can find out where to order it.  I have used this for many years, ever since Kendall quit making it, and have no wear problems at all, other than normal for the miles covered with my machine. I run straight 40wt for my Seattle climate, average temps for riding in the 60's, some say for hotter climates run the 50 wt mono grade, 40wt for winter, 50 wt for the summer.

[Dynamo Regulators Mike]

As has been noted before a centrifugal filter, a.k.a. here as a sludge trap, cannot spin particles out unless they arrive suspended in the oil.  But the trap tube could well fill sooner if particles do not drop out of suspension so readily elsewhere in the engine. So it is better to to have a filter in the system as well if using high dispersant ('detergent') oils. Then the sludge trap acts as the last line of defence before the relatively vulnerable bearing shells. This is the system used in a vast array of modern engine with maintenance intervals in many thousands of hours.

Best not try to use heavyweight (at lower temperatures) mono-grade oils with a paper filter. It could rupture the element or by pass defeating the object and releasing clouds of debris into the system.

The film strength with synthetic oil is much greater. I believe this maintains the low wear characteristic previously added with the ZDDP. So less of a problem than it might be. In practice I have seen very low wear rates using mineral 20W50 and paper filter. The next 50,oo miles will tell 

Another definite tick for synthetic, but not as far as 5W50 and the like which may add to leak issues.

[RogerSB]

Re ZDDP, whatever your tipple - have a look here:-

https://www.duckhams.com/range/

[worntorn]

As has been noted before a centrifugal filter, a.k.a. here as a sludge trap, cannot spin particles out unless they arrive suspended in the oil.  But the trap tube could well fill sooner if particles do not drop out of suspension so readily elsewhere in the engine. So it is better to to have a filter in the system as well if using high dispersant ('detergent') oils. Then the sludge trap acts as the last line of defence before the relatively vulnerable bearing shells. This is the system used in a vast array of modern engine with maintenance intervals in many thousands of hours.

Best not try to use heavyweight (at lower temperatures) mono-grade oils with a paper filter. It could rupture the element or by pass defeating the object and releasing clouds of debris into the system.

The film strength with synthetic oil is much greater. I believe this maintains the low wear characteristic previously added with the ZDDP. So less of a problem than it might be. In practice I have seen very low wear rates using mineral 20W50 and paper filter. The next 50,oo miles will tell 

Another definite tick for synthetic, but not as far as 5W50 and the like which may add to leak issues.

What Jim Comstock found with his scar testing was that the film strength of the synthetics wasn't generally very good compared to many conventional oils but
the friction was much lower than with conventional oils.
For example, the oil I've been using for some time now, Valvoline VR1 conventional 20/50 had relatively high film strength showing failure at 205 lbs load.
It also had a fairly high friction rating of 4.84, not great.
The full synthetic version of VR1 20/50 had about 30% lower film strength showing failure at 145 pounds load.
It's friction rating was wonderful, not even measureable , it was so low.
Jim was searching for an oil that had both high film strength and low friction. He eventually found several that fit the bill.
Some were synthetics, others were semi synthetics.


Glen

[Triton Thrasher]

Trust me, I’m an oil importer.

http://3.bp.blogspot.com/-SkALNbRu7BU/VKk1I2xlakI/AAAAAAABMaU/ybvQsHO9Kz8/s1600/The+Godfather+-+behind+the+scenes+(14).jpg

[bsa-bill]

Trust me, I’m an oil importer.

Ah but Olive oil (and an unusual use for butter if I recall)

[RogerSB]

Trust me, I’m an oil importer.

No! No! No! He's only an actor!

https://www.dropbox.com/s/b8v957t4gh3lm2n/260%20-%20Historic%20Oil%20Brand%20Duckhams%20is%20back%20-%20ZDDP%20%E2%80%93%20What%20does%20it%20all%20mean.pdf?dl=0