Single oil flow to top end mods

[Brian_Walker]

I have a 1952 VCH (Engine# 17) which was built in 1951 and it has a cross over of many of the 51 parts (twin lobe cam, and 1951 timing chest with feed to rockers via a banjo where the earlier pressure regulator was fitted) As far a I know the engine is largely original apart from work I did on it in the 70s. It even has polished steel crank disks from 1937 (I think the factory was using what was lying arround at the time and they had some problems with the cast cranks on the competition engines according to the infomation (AMOCC library) however my issue relates to the timing chest oil flow arrangements.
Trying to put the engine back together with all new bits and pieces I ordered oil pipes, timing case screws, gaskets and fittings from Drag's, when the parts arrived I noticed that the pipes were for rocker feed from the oil return not from timing case feed. I made up a "T" on the oil return line and fitted a blanking plug where the previous banjo outlet was on the timing chest. The fitting was a 5/16 26TPI which indicates 1951, my question now is:
I have removed the plugs, spring and ball from the timing chest as note's from Drag's website indicate that this was not fitted in 1952, further on I notice it was fitted again in 1956 and with an added return arrangement in 57/58 models.
The big question is what will the best arrangement be, and if removing the ball and spring will it reduce the flow to the rockers or big end.
Perhaps the smaller hole in the plug could add some restriction to the flow I wonder if this would be better than removing all?
I wonder if they went back to the ball and spring to improve oil flow to the crank or top end?
I hope someone can give me some ideas on this.

Below is the extract for Drag's website.

"When the rocker oil feed was altered to be supplied by the return to the oil tank instead of at pump pressure in 1952, these valves were deleted. In 1956 an oil pump spring (2220-29) was fitted in the return line along with a S9-1A ball bearing, without a plug. 1957 saw the reintroduction of the plug, ball and spring arrangement in the feed to the big end as used earlier, the only difference being that the part number of the plug had changed to 2150-57. So in conclusion (parts listed in order of assembly):-
1941-51 ohv, Feed = Spring 2154A-41, Ball S9-1, Plug 2150-41; Return = Nothing
1941-51 sv, Feed = Spring 2154-30, Ball S9-1, Plug 2150A-41; Return = Nothing
1952-55 all models, Nothing at all
1956 All models, Feed = Nothing; Return = Ball S9-1A, Spring 2220-29
1957-58 All models, Feed = Spring 2154A-41, Ball S9-1, Plug 2150-57; Return = Ball S9-1A, Spring 2220-29"

Brian

[david.anderson]

Brian
The first thing that you should do is to replace the ball spring and plug. The lubrication is by a plunger pump and all that it takes is a bit of grit under the pump feed ball to stop the suction and then you will have no oiling. In the 57+ models all that the timing case ball and plug do is to act as a back up in the event of the above happening ie there is one valve inside the pump and a back up outside the pump.
In the 41 – 51 models the timing case ball acts as both a pressure regulator to pump delivery side oil to the rockers and it also acts as a back up valve in the event of failure of the oil pump valve. If you remove the plug with pressure fed rockers then 100% of the oil will be pumped to the big end. The plug ball and spring act as a pressure regulator. Oil is pumped to the rockers and it is only when the set pressure is reached that the valve opens that the big end is oiled.
It should also be noted that for the 57 + models a back up valve was also fitted in the timing chest behind the oil pump return. The factory also put out a service note which is available in the members area on how to modify pre 57 timing covers to accept the extra return oil back up valve. I always modify earlier timing cases to accept the return oil back up valve.
I have in 50 years of running my VH done near 200,000 miles. In that time I have suffered 2 separate return oil pump failures. On the first occasion I was with a friend who noticed my bike starting to smoke and leaving an oil trail. The sump had filled and oil was spewing out the breather. A few minutes work at the side of the road and the problem was fixed, however on the second occasion I was unaware of the oil pump return failure and spewed all the oil out the crankcase breather. The bike came to a stop when the exhaust valve seized open in the guide due to lack of lubrication. From that time on I have always run the back up valves on both delivery and return oil.
As your bike originally had pressure feed to the rockers I would recommend that you go back to that system. If you wish to convert to return oil to the rockers then you really need the later oil tank or you will need to make up a reducer to go in the oil line return to the tank to ensure the rockers are actually getting oil. The outlet for return oil within the oil tank is lower than the rockers so the oil will take the lowest least pressure route. The return oil will all go to the tank and none to the rockers. So a tee will not work unless the branch to the oil tank is slightly smaller than the branch to the rockers. Or fit a flow restrictor in the tank return oil line, located after the branch to the rockers. It can take some playing around to get the flow to the rockers right. I converted a pressure feed to rocker bike years ago to return oil rocker feed but would not bother again. The restrictor that I used was a plug having a smaller orifice. From memory I needed one with a slightly smaller size orifice than the internal rocker oil line copper pipe. I adjusted the rocker oil flow by changing the orifice size until I achieved a flow at the rockers that was about the same as the later models.
David

[Brian_Walker]

Thanks for the detailed reply David I will take it back to direct feed. Interesting I have just taken the oil pump off to redo the seatings (the balls are on ebay as SKATEBOARD PARTS FOR SURFA SAM LOOSE BALL BEARINGS 1 COMPLETE SET 7/32" $8 ) I tapped a ball in each then replaced with fresh ones. Interesting two bits of swarf were found in the feed plunger side all ready to foul the seat. I will look up the second pressure regulator mod , I do I worry about oil feed to the rockers as it is hard to see what's happening inside.
Lucky I had decided to look in the timing cover as I found that even though the mag bolts were lock wired it had still moved and the timing chain was way too lose I am now adding some industrial strength hardened star type washers under the lock nuts as well.
Brian

[will_curry]

The magneto mounting on Ariel singles isn't one of Ariel's strong points.
The mounting slots can wear allowing the magneto to twist badly out
of line. It's important to use the correct mounting bolts, not bolts
threaded up to the underside of the head. Lots of nice thick paint
on the platform doesn't help things stay tight as the paint oozes
out from under the magneto. Paint can also electrically insulate the
magneto from the rest of the bike causing other issues.

[nevhunter]

The area where the Magneto locating Bolts move gets worn too. Either replace the plate or weld up the surfaces and slots and remachine them. You have to get it right or have endless trouble with loose chain and misalignment issues. With a BTH magneto or the early models only TWO bolts are able to be used. Nev