Oily R.H. cylinder

The Norton hadn't been getting much use this year so I took it for a 60 mile ride this morning. When I got back I noticed some oil had sprayed out of the joint between the R.H. muffler and exhaust pipe. When I pulled the plugs the R.H. one was wet and from what I could see down the plug hole so where the valves and piston. The top end was done 1500 miles ago with new pistons, rings, valves and seals. Same guides. I'm wondering if (a) could be from composite head gasket needing another re-torque or (b) possibility that the mechanic that assembled the head put a rocker spindle in backwards even though he's a seasoned Brit bike mechanic.

Check the head torque first...it's the easiest. Usually takes 3-4 retorques when I put in a new head gasket. Sounds like you understand the possibilities. If the spindle were an issue it would have likely presented itself before now with 1500 on the engine.

Probably a sticky float washing the cylinder wall. That's where things go south when a bike sits.

If it's accumulating oil then I assume it also smokes, yes? When does it smoke; at idle, decel or under power? That can give you a clue as to the source.

Sometimes the actual sources of an oil leak can be difficult to find. I had a similar leak that was caused by oil leaking out of the original copper head gasket from the pushrod tunnels and then migrating around the fins. I cured it with a composite head gasket and a little extra RTV smeared around the pushrod tunnels after a top end rebuild. Try retorquing the head and see if that cures it. Like illf8ed says, these bikes need several retorques and valve adjusts after a new head gasket is installed. I generally do retorques and rocker adjusts after a few heating and cooling cycles, again after 50 miles and a few more heating and cooling cycles, then again at 500 miles. That generally will do it.

Most common cause is the RH banjo to the head and related line and fittings. These leaks will manifest as you have described and although not easy to seen, will leak much more at speed. The oil will drip down onto the cylinder top, run down forward showing up around the exhaust area.

You might want to check this first.

Wet (presumably oily) combustion chamber on RH side? Recent top end rebuild?

Another potential cause could be the drain back oil gallery on the intake side. Since the head and barrel had been removed for the work there are two opportunities to inadvertently plug the drain gallery with gasket compound or sealant; one at the barrel to case surface and one at the barrel to head surface. You would probably have seen symptoms sooner; maybe they were there and you did not notice.

I am not sure how a blown Norton head gasket would pump oil into a combustion chamber but I will defer to others on this one. Retorquing is a relatively easy test/fix and is just good practice - remember to check and adjust valve lash after retorquing.

If you have an RH04 head there may be a crack in the port near the guide that is leaking oil from the rocker box. Pulling the carb and manifold you may be able to see something. A slipped seal or incorrect guide to valve stem clearance could also be a factor. One of the intake guides could have been damaged during tear down where the valve rocker tip may have been upset, then drug/forced through the guide yet a seal would mitigate most valve stem to guide clearance problems.

I would chase down the easy stuff first with things such as:

• retorque the head,
  check rocker spindle orientation
  visually inspect to see if valve guide seals are in place and properly seated, and
  confirm that the oil drain gallery in the intake side valve spring pocket is open (pour some oil in there and observe if it flows out).

If this just began to manifest itself recently and the above remedies and inspections don't resolve it, I would be looking at maybe a wrist pin clip is loose and scraping the cylinder or something along the lines of the piston/rings/cylinder interface.

Please keep up posted as this will be a learning experience for everyone.

The oil problem is internal not external. I am going to start with the simple stuff first because I really don't want to tear into the engine during riding season.

zotz said:

The oil problem is internal not external. I am going to start with the simple stuff first because I really don't want to tear into the engine during riding season.

Click to expand...

zotz,
Looking at your avatar picture, I am assuming that your bike is 750. :roll: Take off the intake rocker cover and pour some oil onto the right hand side valve spring area and watch if the oil is draining down. The hole is on the right hand side of the valve spring. Use a mirror if necessary and a good light. Tilt the bike to the right. If it is draining then that eliminates this cause. You might have a valve guide seal that popped off.
Let us know what you find.
Cheers,
Thomas
CNN

zotz said:

I'm wondering if (a) could be from composite head gasket needing another re-torque or (b) possibility that the mechanic that assembled the head put a rocker spindle in backwards even though he's a seasoned Brit bike mechanic.

Click to expand...

For new installed composite head gaskets, I start with two heat cycles (run engine till the head is hot to touch then shut down), each time torque on a cold engine. Then do a 50 mile run ... then another re-torque on a cold engine...adjust valve tappet clearance as per your type of cam and then +_1000 miles which I will do a final re torque and tappet adjustment. Your engine should be stable from here on in. I pre coat these composites with Wellseal as per Mick Hemmings suggestion.
YMMV.
Cheers,
Thomas
CNN

Its not impossible with newly installed valve guides, if it wasn't done with the head heated enough,
the guide wasn't well enough seated, and the oil could be tracking around the valve guide and into the cylinder.

About the only way to test for this is to disconnect the oil feed to the rockers, and run it (briefly) like this.
(A short time won't hurt it, too much, without lube).
If the smoking stops, the problem is in the top end.
Wiking the right grade of loctite in around the guide can often cure this.

I haven't followed this closely.
Some heads had a problem with porosity, and oil can percolate through the aluminium !

Rohan said:

Its not impossible with newly installed valve guides

Click to expand...

New guides not relevant here.

From the original post:

zotz said:

Same guides.

Click to expand...

Could be that the guide(s) have come loose then ....

zotz said:

The Norton hadn't been getting much use this year so I took it for a 60 mile ride this morning. When I got back I noticed some oil had sprayed out of the joint between the R.H. muffler and exhaust pipe. When I pulled the plugs the R.H. one was wet and from what I could see down the plug hole so where the valves and piston. The top end was done 1500 miles ago with new pistons, rings, valves and seals. Same guides. I'm wondering if (a) could be from composite head gasket needing another re-torque or (b) possibility that the mechanic that assembled the head put a rocker spindle in backwards even though he's a seasoned Brit bike mechanic.

Click to expand...

Seeing blue smoke on deceleration? If so, intake valve guide seal. Sounds like you may have both internal and external leaks.

Only the 850's had seals on the inlet guides ?

I had a guide seal come loose on my 850 a good while back, not long after a rebuild,
and it only produced a dark looking plug, and a faintly oily smelling exhaust on that side.
Fitting another restored it back like new.

Rohan said:

Only the 850's had seals on the inlet guides ?

I had a guide seal come loose on my 850 a good while back, not long after a rebuild,
and it only produced a dark looking plug, and a faintly oily smelling exhaust on that side.
Fitting another restored it back like new.

Click to expand...

Could be, my only experience is with an 850. I guess my '61 Dommie doesn't have 'em if I am remembering correctly. Valve guide seal had come off on the Commando and oil consumption was significant (quart per 1000 miles) as well as puffs of blue smoke upon deceleration observed by riding buddies behind! Fixed this issue with a new set of seals and also solved the external oil leaks at the same time with a new head gasket and better sealing around the pushrod tunnels as well as silicone gaskets for the rocker covers. Bike is pretty oil tight now.

another possibility is that the oil is coming up past the rings. Try fitting an engine breather and not a cheap one. Comnoz sells an excellent bolt on unit though pricey. But it is beautifully done and effective. Try that before tearing the motor down. If it doesn't solve the problem you needed one anyway. I would do that long before removing the head...rule out a big variable. This has worked for me on a couple of motors.

I should correct that comment about valve guide seals - seems the 750 got them in the early 1970s, per another thread started here on that subject. (is it the same seal, the 850 had different guides ?)
That much oil sounds more than just a seal though.

On the NOC forum, there was mention of checking that the drain holes behind the inlet valve springs were clear and draining. Not easy to see or get at, but if you watch that the oil drains out of the well around the spring can give you an idea.

zotz said:

The oil problem is internal not external. I am going to start with the simple stuff first because I really don't want to tear into the engine during riding season.

Click to expand...

Intake valve seal failure my guess.
It happened to me on a new rebuild.

OK. So I was finally able to get a look into the motor this morning and as far as I can tell the R.H. intake valve guide seal has popped off. I see at the same time a posting of an old thread about valve guide seal renewal without removing the head but all the pictures for special tools are all missing. AAAArrrrrgggghhh! Anyway, I really don't want to pull the head if I don't have to so I will probably try to figure this out. Also as these are the so called "better seals" I have read that they are problematic for popping off as they grip the valves too firmly. I don't want to keep doing this. Has anyone tried using them with the spring removed? On a related note, I have noticed that one exhaust valve keeper has split in two right down the middle basically creating a 3 piece keeper arrangement on that valve. As I never go anywhere near redline does anyone see any issues here with leaving it as is?