Ariel Owners Motorcycle Club

I use SAE40, which seems to be used also by many others. It made a significant difference on my engine. Have you checked which oil pump you have?

I have the early pump and i have replaced the balls and springs overall it seems in good condition ,i am currently using sae 40 oil. The quill is straight and parallel and unworn and protrudes 40mm

You can check whether the oil ways in the big end are clogged up by pumping oil into the hole for the quill. You need to pump for some time to see oil dripping out from the crankcase.

The oilways in the crank shaft are clean and easily allow oil to the big end and there was no sludge in the sludge trap , i have reassembled the engine carefully but with sae 40 engine oil i still am getting considerable amount of oil reaching the magdyno .i have blanked off the lower breather as it was leaking from there . So at this point i am running out of ideas

Have you checked for blockage in the other crankcase breather i.e. the one on the side of the cylinder block from the tappet chest? If this were blocked then the only route for blow-by would be into the timing cover, possibly causing your symptoms

Also check the blow hole in the crankcase from the cam chest into valves, this would cause a similar effect. I got a spare VB engine a while ago that someone had used a cylinder base gasket from a late OHV without the hole in the gasket. You can check this by just removing the tappet cover and poking something down the hole between the tappets.

Pete

Hello Pete ,yes i have checked the valve chest breather and the drain hole into the timing case is clear .the only other option is to move the timing cover breather to the later higher position as used on later singles . its easy to do as the cast boss for it is already there .at this point i have run out of ideas . The valve chest breather on my later VB is larger so it was obviously a issue that ariel had noticed .

I am sorry, but I also cannot think of any other cause for your problem. I haven't managed to avoid the build up of oil with the bigger pump and always blamed the higher oil drain hole in combination with the later, bigger pump.

Fit bigger Pumps to the singles and you will enter a World of Woe. Motor runs hotter and oil leaks from the engine.. They never improved the Oil pick up Point. Oil only goes fully to the Bottom when the engine is stopped. Some sort of scraper would help. Nev

Hello there
just an update on my issue .I have moved the breather to the later position where the boss was already there but not drilled ,and blanked off the lower position . this has improved things a great deal with no oil coming out of the breather so i am quite happy with this solution .

Any pictures Oliver?
Of your new breather position.
Gary