The engine is away right now being repaired, I have neither the engineering equipment, nor, and more importantly, the skills to carry out all the work that needs doing, so I am unable to provide photos of the worn/damaged parts right now, but I might be able to at some point.
ET: Engine (Twin) Oil, is there a definitive answer?
- Thread starter Peter Holmes
- Start date
I like the Valvoline VR1 racing 20 50 which is a mineral oil with zinc easy to get and does the job.
Been using this for a few years, lots of the classic racing guys recommend it they use it hard and I have not heard any bad reports.
Good for air cooled engines.
I do replace it every 1500 miles or so, drains out clean although I usually start with a clean system.
Never used it to break in an engine usually start with an Amsoil.
Also used Amsoil Twin 20 50 for a number of years on my big twin race engines great stuff available in UK from Demon Tweeks.
They also keep the primary and gearbox oil from Amsoil.
Order one day here the next great bunch of lads.
Vincents VR1 and Tuned Big S/S Twins Amsoil.
Al
Been using this for a few years, lots of the classic racing guys recommend it they use it hard and I have not heard any bad reports.
Good for air cooled engines.
I do replace it every 1500 miles or so, drains out clean although I usually start with a clean system.
Never used it to break in an engine usually start with an Amsoil.
Also used Amsoil Twin 20 50 for a number of years on my big twin race engines great stuff available in UK from Demon Tweeks.
They also keep the primary and gearbox oil from Amsoil.
Order one day here the next great bunch of lads.
Vincents VR1 and Tuned Big S/S Twins Amsoil.
Al
Always grateful for any advice, I think Big Sid was the first person on this forum to recommend Valvoline VR1 20-50, I will give it a try. With regard to Amsoil Twin 20-50, that appears to be a fully synthetic oil, there seems to be conflicting advice on using fully synthetic oil, some people think using it has caused my big end failure, others think it is good to use, the stakes are pretty high on this, fixing wrecked engines does not come cheap, confused Vincent owner!
What I can’t understand is that if an oil is so slippery that the rollers skid rather than roll then how is the damage done? Surely as soon as any friction is generated then the rollers will roll. I’m not saying I’m right and others are wrong I just don’t understand!
Neither do I.
don't have a formula to justify this reasoning but i imagine it is rather like putting a flat on a tyre.
Again, this theory was promulgated pre internet and in photo copied 'club' magazines when people with the biggest swagger were listened to.'
Just sayin'.
Many years ago , The late Don Alexander had an oil man check our bikes out and said ,
The new oils were not any good ,For our old bikes,
So for me , Single grade 40 summer, 30 winter,
Or for my poor old Comet, 50 !,
Still going well in 2023.
The new oils were not any good ,For our old bikes,
So for me , Single grade 40 summer, 30 winter,
Or for my poor old Comet, 50 !,
Still going well in 2023.
I don't think you received an accurate diagnosis. Synthetic oils work fine in Vincent engines. The problem is not caused by lack of friction, but too much oil in a conrod roller bearing. As the roller turns, the oil creates a "bow wave" as the roller plows the excess oil in front. The oil tries to exit underneath the roller, but there is not enough clearance in the bearing for that to happen. The result is that the roller tends to stall and it begins skipping. This causes heat damage as well as mechanical damage.
Generally, the solution is to verify that the oil cannot build up inside the bearing by increasing the clearance on both sides of the rod. As long as oil is dribbling into the flywheel, the exit doors for the oil can be wide open. You do not want any extra oil building up in the bearings because the oil cannot get out. Extra oil in the rod creates a hydraulic problem not a "slipperiness" problem. Conventional oil would do the same thing with too little side clearance for the rod. This has happened quite a lot in Vincent engines over the years.
David
David, I thank you for your input and knowledge on the subject, so in your opinion, once my flywheels, con rods and big ends are rebuilt correctly
(and I am very confident that they will be) I can continue using Motul 300V 20-60w fully synthetic oil without any fear of further big end failure, as I originally posted, every other component within the engine, and specifically the timing chest components have survived very well indeed using this oil.
(and I am very confident that they will be) I can continue using Motul 300V 20-60w fully synthetic oil without any fear of further big end failure, as I originally posted, every other component within the engine, and specifically the timing chest components have survived very well indeed using this oil.
On a nice freshly built Vincent engine I go for a full mineral run/break in specific oil.
For the initial start up and break in period.
Dumped after 100 miles of laboured riding up and down the hills around Belfast.
I am very flash using VR1 for the next short period to flush out.
New filter and off we go again a longer run flush out oil change and filter clean.
Few hundred miles maybe a wee weekend away.
Then onto a full mineral oil VR1 20 50 is a great quality oil, I do not ride in very cold weather apart from the summer in Scotland...
Again 500 miles dumped and new filter onto the normal service régime from here on in.
Will stick with VR1 then throughout the engines life with oil changes every 1500 miles.
For older motor designs I try not to use any synthetic products inside, there are many more experienced riders on here who can explain why we should not use synthetic lubricants apart from in the bedroom, stuff like the types of metals used in older engine internals, bushes etc.
I have stuck with their sage like advice.
Oil is a very personal thing with lots of options out there.
I weighed up the pros and cons of synthetic and stuck with mineral oils in Vincents.
Some great straight mineral oils out there also, again I choose the VR1 easy to get in motor factors fairly affordable and has the right stuff for older engine designs, good constant viscosity.
Al
For the initial start up and break in period.
Dumped after 100 miles of laboured riding up and down the hills around Belfast.
I am very flash using VR1 for the next short period to flush out.
New filter and off we go again a longer run flush out oil change and filter clean.
Few hundred miles maybe a wee weekend away.
Then onto a full mineral oil VR1 20 50 is a great quality oil, I do not ride in very cold weather apart from the summer in Scotland...
Again 500 miles dumped and new filter onto the normal service régime from here on in.
Will stick with VR1 then throughout the engines life with oil changes every 1500 miles.
For older motor designs I try not to use any synthetic products inside, there are many more experienced riders on here who can explain why we should not use synthetic lubricants apart from in the bedroom, stuff like the types of metals used in older engine internals, bushes etc.
I have stuck with their sage like advice.
Oil is a very personal thing with lots of options out there.
I weighed up the pros and cons of synthetic and stuck with mineral oils in Vincents.
Some great straight mineral oils out there also, again I choose the VR1 easy to get in motor factors fairly affordable and has the right stuff for older engine designs, good constant viscosity.
Al