Rocker spindles 650SS

david.....the flat should face away from the centre of the head.i had the same issue as you some years ago.A favourite mod years gone by was to replace the [spiraled] dommi rocker spindles.

with atlas/commando [plain] spindles.and move the oil feed pipe from near the oiltank and have it feed from the timing cover as per commando just below the pressure release dome nut. 

david.

also check that you have three start oil pump gears.some poeple fitted six start gears as per the atlas/commando.and that can cause over oiling....

hello if your having over oiling issues this could be down to the small oil holes being blocked. As Most of the oil runs down the pushrod tunnels on the exhaust side and the rest runs down an oil hole at the inlet side that goes down the side of the right side inlet valve spring  and down the back of the barrel and into the timing case,  so something is blocked somewhere  and needs a clean   now have fun   yours   anna j

Hi David mine had the intermediate  type plain rocker spindles with the no flat. Upgraded to the plain type with the flat which faces outward (away from the inside of the head) with the 6 start oil pump as per Commando. My issue was the spindles were turning in the head due to the interferance fit being lost over the years.

Actually got the same issue on my Commando when I came to strip it they were turning on that to and sat to deep on both bikes to engage with the tangs on the spindle covers. 

If they arn't turning the book recommends heating the head, mine were spinning very freely on a cold engine hence the issues.

On my 650 SS some had worn into the head deeper as they had been turning so were all set at different positions ended up using a kit from RGM that stopped them spinning thanks to the adjustable allen keys.  Norvil also do some with longer tangs.

Some video clips up on my youtube channel about when I did it with my 650SS. If you put norton.rider rocker spindles into the youtube search

Hope this helps,

Tom

 On Dommies  and Atlas the Inlet side does not drain well ,there is a hump in the middle of the head so oil has to find its way down the small drain hole, With the high pressure system and the shaft holes facing the pushrods there can be too much oil at the inlet valves and it gets drawn in.I would have thought that facing the holes away from the pushrods would increase the pressure and force oil along the rocker bushes giving better lubrication to them. The cam tunnel trough gives good lubrication to the cam (except for those silly enough to have removed it!) .I have fitted oil seals to our Atlas inlets which may solve the issue. I may have to do the same to the 99 which is also now getting a bit  too much oil on the plugs since I "improved" it.

The spindle flats serve as small reservoirs. Once the engine is running the camshaft then receives a combined splash, drip and oil mist feed. The motion of the pistons helps with lubrication of all the bottom end due to what is known as the 'bellows' effect. ie. the pushing of oily gases around the crankcases. This also works in the timing cover. If you look carefully you will note small feed holes that point at all the chains and gears. They look like drain holes but also serve as part of the oil feed system when the pistons descend. This arrangement worked fine for the early Dominators and only gives problems when people mess around with the breathing system.

Its amazing  that such an obscure and almost irrelevant detail on some outdated old engine can occupy the thoughts of so many   intelligent  and creative people.  We should all get out more,  but not yet , crappy weather.

The trough that is mentioned may not add that much to the lubrication, but maybe more a function of other need for oil, heat removal. The nose of the lobe will be very hot as it has passed the tappet, and thus the cooling hit in the the trough helps keep the cam lobe cool. The lobe can get hot, I have a microscope photo of a tappet wearing molten cam, the tappet was not even affected by the heat, it could be refaced and reused. 

One thing I have noticed is that standard cams fail more than performance cams, the higher the lobe the more chance of hitting oil.? Any oil that is hit in the trough by the lobe I suspect would be flung off, or splash / airborne oil takes over, so the trough may not add much to the lubrication.

Varying crankcases have varying troughs, and you can easily check this with the cases in a vice. 

Having seen the build up of oil above the tappets and how slow it drains past them, I would prefer the oil to be doing a job and not just sat there.

Looking forward to Tony's expansion. I know a lot of thought and work will have gone into it. 

Could it be that the current manufacturers of the "performance cams" pay more attention to the heat treating and materials than did the factory?

Mike

My 60 year old cams and followers are still in perfect nick after a life of riley  bathing in their trough.

Hi Team- New to the NOC- this is my first post.

 I have a bone stock 1966 650ss that I just restored- Got it as a basket case- now she lives! No more than 50 gentle miles on it in several short trips. 
 When she gets hot- we get a nasty metallic chafing sound developing in the left hand exhaust valve area- . Spray a little lube on the valve spring/stem and it goes away.... temporarily....

 I'm watching in there while she runs, and I don't see whole lot of oil flowing down the pushrods- nor do I see whole lot of "mist" being generated in the front . A little oil oozing out the ends of the rockers/spindles where they meet the case and drooling down the sides but that's it. There doesnt seem to be much reaching the valve springs/stems

Plenty of oil in the back , i.e. -the intake valves- its even pooling up a bit around the base of the valve guide  and lots of "splash"- Three mins with it running with the cover off and it gets the tops of the carbs wet with oil. ... but none of that is happening in the front.
Not sure what action would be generating the "mist" necessary to wet the exhaust valve stems in the first place. Seems like it should be a lot wetter up front there.

Now, I didn't do the motor- I sent it to a chap who I know/ trust very much and he did the work.
But I am guessing I should pull the rocker spindles and suss it out.  Blow everything out clean and start again
So -Here's my questions:
-Can I pull them  without removing the head?

And on a late 66 with ( I am guessing) the 6 start pump, what type of spindles should be in there? Are there any upgrades/tricks that you would suggest?

Cheers,

 Tristan

Sounds like the small oilways are pretty blocked ,if its a high pressure system there should be plenty of oil. You are going to have to see what you have. Its all accessible without removing the head.Its possible that  just the inlet spindles are facing the wrong way and diverting the oil.

Hello Tristan, you say you have a problem once the engine is warm , to hear a scuffing sound above the sound of the engine suggests it might be something other than a tight unlubricated valve, and yet, as you say, the sound goes away with the addition of oil. Is it likely to be an assembly problem, how conversant with the Norton engine is your engine builder?  There is an oil drain hole in the rear right hand side of the cylinder head that drains oil back to the timing case, if the cylinder base gasket were to be put on incorrectly the crankcase hole would be covered and the oil would build up in the head , not all gaskets are both left and right handed, there is a similar hole in the head gasket. The other end of this drain hole can be accessed from the rear of the timing chest, a low pressure air jet directed into this hole should tell you if it is clear. A lot of members seem to suffer over oiling within the cylinder head and follow the instructions in " the book" to rotate the rocker shaft so that the oil hole faces away from the pushrods. This will restrict the oil flow into the rocker arm and produce the effect you have seen of oil squeezing out of either end of the rocker. I think you definitely need to carefully dismantle the head, taking notes or pictures as you do so. I don't know when it was done, but later engines have oil drain holes in the exhaust valve pockets, these are so effectively masked by the spring seats as to be almost useless. I have within this thread a couple of posts which I had hoped might explain some of the problems with the valve gear and how to overcome them , it might be worth glancing through them again .

Good luck with the investigations, Cheers, Ian

PS:- Try and warm the head before withdrawing the rocker shafts, it's not good to remove or replace them cold, localised heating with a hot air gun usually works.

If the holes all line up with the high pressure system then a lot of oil will go through the head. This could overcome the valve seals (when fitted) and is too much for an Atlas (which has no seals). It could also reduce the oil pressure to the crank which on later engines had oil bleed holes in the rods for piston lubrication.

It is physically impossible for the oil pump to cause over oiling, 3 start or 6 start. The way the pump is designed prevents it. 

The oil circuit can cause over oiling. Considering that the feed to the scrolled rockers and 3 start pump worked for years, just why did they change to a 6 start pump. Did they need to, did they fully test the 3 start pump, I don't think so. The 6 start pump is very good, works at just over 50% of its capability and delivers a huge amount of oil per minute.

The reason to remove oil flow to the cam is a strange one, and goes against all the thinking then and now. Getting more oil to the cam by aligning the holes into the head makes sense, despite the hole in the rocket ball end being shut off in the cup of the pushrod for a long portion of cam rotation is the same no matter which way the hole faces, but when it has the opportunity to deliver oil to the pushrod tunnel it can't. Many other pushrods in the automotive world are hollow for a reason, to get oil to the cam.

There are two things that suggest that getting more oil to the cam is a good idea. First, the Domiracer tappet had double chamfers and two holes drilled in them to obviously allow oil past the tappet to the cam. Seems that the race shop was on the other side of the planet - why did they design them that way, and why not introduce it to road models. If they had then no over oiling in the head no matter which way your spindles were fitted or what style. Second, anyone with an optical thermometer just check out the temperature at the tappet tunnel area near the barrel flange. Then decide how you are going to fit your rocker spindles.

I noticed the temperature at the tunnel when the manufacturer of the one piece tappets asked about working temperature in this area. At the time thought it was quite high but there was little else out there to suggest it was either not normal or that it could be be made cooler.

When you break this whole thread apart and look at each part on its own, then what was considered the norm in the past, needs questioning, as it may have cured the result of the problem but not the cause. 

I can agree that more oil to any cam is good,particularly for the Commando motor which has had far too many cam failures. I have not had any measurable cam wear  over  60 years of "Dominating"  with the 3 start  low pressure system and a functioning cam trough. These motors get very little oil down the pushrod tunnels and the ex valve chambers usually look dry. The rocker spindles do wear though so I have recently arranged for them to get a little more oil. The Commando motor with its cutaway trough  needs  a good oil supply to the cam no doubt. But even the bigger pump and double speed gears do not deliver the oil where its needed.

Dominators had very substantial camshaft oil troughs which worked. When the engine stopped the trough retained oil so that when the engine was restarted there was oil immediately available. I have heard it mentioned that some owners tried for some reason to remove the trough,  I feel the trough is so much part of the crankcase that this would render the crankcase useless if they managed to succeed. 

Mention has been made of the damage to Commando cams and followers.

The Commando trough  is not so pronounced as that in the Dominator, but is helped  by the inclination of the engine,  but not sufficiently to counteract other problems, some of these being badly cast cases. An example of this being a MkIII finished only last week. The right hand case on this engine had a fully machined trough, the left hand case had an unmachined ledge sloping down to the joint section of the case,  this resulted in a 5/16" step down.  With the case set up on the bench, oil poured into the trough remained in the r/hand side but ran off the l/hand side, the camshaft from this engine only had three lobes the fourth, on the l/hand side was 50% worn away, the other cams and all the followers were badly scuffed. The rocker shafts were facing away from the pushhrods which is why all the oil from the uprated pump is NOT going where you need it.                                                     On this engine a new trough was fabricated and welded into place exactly matching that in the right hand case. Further mod's were made to the cam followers to increase the  oil flow past them and so avoid flooding the tunnel and head.

Ashley asks if it was required to fit a six start pump, it had been altered by fitting larger gears, but spinning the pump twice as fast doesn't  necessarily mean it will deliver twice the ammount of oil.   Do we know if the enlarged pump was tried with a three start drive, might this have been all it needed?

The higher capacity oil pump (marked 'S') came about with the arrival of the 650 and 750 engines. These having larger crankpins compared to the 500cc and 600cc motors. All the engines using low pressure rocker feeds. A couple of years down the road and high pressure rockers feeds and conrods with bleed holes turned up and a quick fix to keep the pressure up all round was to double the speed of the oil pump. Which as Ashley says was more than enough for the job. The drawback of doubling the speed of oil pump is the higher rate of internal wear. Fortunately, the excess of oil pressure covers this for a lot more engine miles but wet-sumping then becomes an issue.

I think that the 88SS had the higher capacity oil pump but kept the 3 start gears for all of its life. Fitting a 6 start gear would just be wasted as the pressure release valve would just be endlessly dumping  excess oil in the timing cover.

The Manuals are all correct depending on which type of Rocker Spindles they are referring to. Right from the first Dominator engines, up until Pressure Fed Plain Rockers arrived the system consisted of scrolled spindles fed by a Low Pressure Return Side Feed from a 3 Start Oil Pump.  The spindle flats in all of these machines faced inwards towards the spark plug,acting as a small oil  reservoir for cold engine starts.

However, just like crankshafts, when the engine was not run for some time the small oil reservoir drained away leaving metal on metal contact until the engine was next started and the return feed was able to, once again, dribble enough oil up to all 4 rockers. This could take some time, while the rocker turned on a reduced area, scrolled spindle. Inevitably the rocker spindle clearance grew to the point where the flat was colllecting the oil flow and then just dumping it onto the valves ends causing smoky engines.

This problem got worse when the SS headed engines arrived with stronger valve springs and higher lift camshafts.  At which point somebody decided that turning the spindles 180* put the flats at the top, facing outwards, was a good idea to help with lubrication but not over-oiling of the rockers. A practice continued when the plain spindles and a pressure fed system arrived. 

If your engine does not smoke then leave the spindles as they are.  Early Maintenance Manuals will mention scrolled with spindle flats facing inwards and later books will suggest the opposite.

My Dommie has a 6 start pump and top feed from the low pressure return.  I've never found the need to remove rocker spindles (they don't need to come out to remove valves or valve guides) so I have no idea which way the spindles face. But they've never given any problems...so far...