Oil issues (more)

Les:

I was thinking about your question and figured the following: (I am sure that if I am wrong I will be shortly corrected)

At idle there is very little oil being returned to the tank. The amount of oil being sent up the branch fitting on the oil return pipe to the rockers will be very little as the amount diverted depends on the back pressure in the return system. Also, there is a lot of air in the pipe as the return side of the oil pump has a larger capacity than the supply side. As the revs come up the pressure in the return side will raise sufficiently to cause oil to be shunted up the rocker feed pipe.

So, at idle, how much is not enough. There is very little loading in the rocker gear at idle.

Just my brain working overtime on a cold morning.

Mike

Hi Les, the supply to the rockers will be very little on tickover. If you have done the "finger" routine I would ride it for a few miles then check in the exhaust areas to see if dry or lubricated, alternatively you could hold the revs at about 3000 while looking in the exhaust valve chambers.If no oil you can fit a tank part from the Jubilee to boost the flow or make up a restrictor to the tank return to push oil more to the rockers. Don't think they need much oil,just some.

Previously les croston wrote:

hi,i have run the bike and can say there is an oil feed through the spindles,not a lot but visible.interesting about the jubilee part,on the model 7 web site there are a couple of comments which say their models have this fitment on the tank,and their model 7s are all original,a pic shows a spring,steel ball and slotted receiver.i suppose the problem is trying to get one.thanks again for replies

Hi,

That sounds like a Velo non-return valve. There is a Commando thread about those fitted in the feed line. Should be safe in a return line.

Cheers

Peter B

hi all,i have been reading the various comments on recommended oil and circulation with great interest so i would like to put my question in re my 55 model 7.it is very near restored,engine starts up fine,previous owner had a rebore done,the new pistons confirmed it,he also had receipts for work done which included overhaul of the oil pump.the bike starts well and idles ok,whilst ticking over there seems to be little or no oil to the exhaust rockers,this was checked with the oval plate and rocker covers off.the inlet rockers are getting a supply but when i cover the return pipe in the tank with my thumb, oil then flows ok through all 4 rocker spindles. the conical seal in timing cover is new,relief valve not sticking and new oil pump gasket.i have put in castrol classic oil,xxl40,is this ok?i dont want to run it until hot in case of damage to spindles.there is a bit of pressure in the crankcase,i get the occasional oil spurting out the engine breather,a bit more than what i would like,also there is a good oil return to the tank,albeit it alternates between a steady flow and trickles.finally,when i increase the revs slightly it is still scarce of oil to exhaust spindles and it is not sumping, hope i or someone,lol, can sort it,thanks,les,

Hello Hope its not too late we in the NOC Do NOT advise to fit anything in the oil lines between the engine and oil tank, other than a oil filter ! the oils you need are Castrol LX 20/50 or Morris 20/50 millers 20/50 sae this is the best oil you can use in a Norton twin , thin oil for easy starting . in my old Norton manuel it states us Shell Sae 30 for summer runing , and a Sae 20w for winter this old Norton manuel was printed in 1953 from the Model 7 and model 88

Witch I own one, and its will be run on 20/50 the same as my 650 twin

Previously les croston wrote:

hanks mike and robert,i will run it up tomorrow and see what happens,will let you know ,cheers,les

Hi Les.

I take it that you have checked the position of the rocker spindle to make sure the oil supply hole is not partially covered by the spindle itself? You know that the spindles have a flat on them where the rocker arm rocks, and the flats should face towards the valve it operates. I read somewhere that the oil feed hole in the cup and ball assembly, where rocker arm meets pushrod, can get blocked or be positioned wrongly. One other thing you could try is rotating the inlet valve spindle so that the flats face away from the valves, This reduces the oil to the inlet valves and increases it to the exhaust valves.My bike, a 1960 99, has a rubber oil pipe from the junction at the oil tank return pipe to the cylinder head. I disconnected it, raised it above the cylinder head level and pumpedoil down it with my oil can. Iloosenedthe end plates on the spindles and could see the oil ooze out. I tightened the plates and was able to checkfor oil at the rocker/pushrod interface. As others have already said, the oil flowto the valves at tick-over isn't great, but sufficient for the enginesneed.

Peter M

,

Previously les croston wrote:

Previously peter_maple wrote:

Previously les croston wrote:

hanks mike and robert,i will run it up tomorrow and see what happens,will let you know ,cheers,les

Hi Les.

I take it that you have checked the position of the rocker spindle to make sure the oil supply hole is not partially covered by the spindle itself? You know that the spindles have a flat on them where the rocker arm rocks, and the flats should face towards the valve it operates. I read somewhere that the oil feed hole in the cup and ball assembly, where rocker arm meets pushrod, can get blocked or be positioned wrongly. One other thing you could try is rotating the inlet valve spindle so that the flats face away from the valves, This reduces the oil to the inlet valves and increases it to the exhaust valves.My bike, a 1960 99, has a rubber oil pipe from the junction at the oil tank return pipe to the cylinder head. I disconnected it, raised it above the cylinder head level and pumpedoil down it with my oil can. Iloosenedthe end plates on the spindles and could see the oil ooze out. I tightened the plates and was able to checkfor oil at the rocker/pushrod interface. As others have already said, the oil flowto the valves at tick-over isn't great, but sufficient for the enginesneed.

Peter M

Hi Les and Peter, unless I have read the 60's owners handbook/manual incorrectly, the flats with the oil hole on them on the scrolled rocker spindles should be fitted so that they all face towards the pushrods, ie the centre of the head and away from the valves.

Terry

,