Smoky ES2

Previously wrote:

Hi All,

A couple of months ago I had written to this forum about a couple of oil leaks I had on my 1954 ES2. One in particular was bothering me as it came through the upper rear seam of the timing chest. On further investigation I found that the oilway at this point leading to the oil way in the back of the barrel was utterly and completely blocked. This led me to believe that this was the reason for the odd timing chest leak. In fact the leak has stopped ever since I cleared the hole but I now have a rather smokey exhaust. So I am guessing that the previous owner may have blocked this oilway purposely to stop the smokey exhaust and put off a rebore.

Has anyone experienced such an issue? How critical is the oil supply to the back of the cylinder, doesn't the piston/cylinder get lubricated anyway from oil flung up by the flywheels?

Best regards,

Albert Pisani

Malta

Hi Albert

I also have a similar problem, my ES2 is a 1947 model, I had the barrel re-bored back to standard, new JP piston and rings, have tried various combinations of ring types. Have now done approx 3000 miles and have stripped it down again, found excessive oil ring gap .035". I had restricted the oil hole in the bottom of the barrel previously this did improve things. I am now going to seal the oil hole, fit a new set of rings and try again. The piston skirt will pick up plenty of lubrication from the flywheel splash. Also read on here before of others who have also sealed this hole. Another reason could be an excessive sump oil level, my oil pump scavenges OK and it would be difficult to lower the working level.

Will let you know how it goes, the blue haze is one fault I do not wish to accept. These old Nortons certainly keep you thinking.

Best regards

Paul

Interestingly, this whole subject of oil feed to piston via a drilling in the barrel has been thrashed out by the Panther website, without any resolution. Some reported rapid ring wear after blocking the hole,some said Cords rings offered a cure, some said cords rings wore their bores.The position of the hole with relation to the oil ring was mentioned.My Panther has three plain rings, and doesnt smoke.My ES2 is 60 over and worn and doesnt smoke.I dont want to get embroiled in an oils aint oils debate. I have allways used oil marketed for Detroit two strokes in my old bikes, currently Shell Rotella DD 50. Its formulated[I think] to burn without smoke or smell, as Detroits burn a lot of oil.I suspect modern additives burn a lot smokier than in the old days, because vehicles aint allowed to burn any oil nowdays.Regards John.[ There are still a few old Detroits on the roads here, a lot more than ES2 s I bet.]

Previously wrote:

Hi Paul,

Many thanks for your answer.

I have just come back from The Irish National Rally where I used my ES2 smoke and all and that is why I hadn't replied earlier.

I was reading only this morning about this problem in my Franks Norton book where this specific problem is mentioned. The Author suggests that closing the metering screw down further on the timing chest cover should cure the problem.

As it happens my Norton being 1954 does not have this so I believe that my only course of action would be to rebore what seems to be a worn barrel (now to +60) and if this doesn't cure the problem try to fit some sort of restrictor in the said oilway as one does with G3L Matchlesses to stem the flow.

I too cannot accept the trailing haze syndrome!

Best regards,

Albert

Previously wrote:

Hi All,

A couple of months ago I had written to this forum about a couple of oil leaks I had on my 1954 ES2. One in particular was bothering me as it came through the upper rear seam of the timing chest. On further investigation I found that the oilway at this point leading to the oil way in the back of the barrel was utterly and completely blocked. This led me to believe that this was the reason for the odd timing chest leak. In fact the leak has stopped ever since I cleared the hole but I now have a rather smokey exhaust. So I am guessing that the previous owner may have blocked this oilway purposely to stop the smokey exhaust and put off a rebore.

Has anyone experienced such an issue? How critical is the oil supply to the back of the cylinder, doesn't the piston/cylinder get lubricated anyway from oil flung up by the flywheels?

Best regards,

Albert Pisani

Malta

Hi Albert

I also have a similar problem, my ES2 is a 1947 model, I had the barrel re-bored back to standard, new JP piston and rings, have tried various combinations of ring types. Have now done approx 3000 miles and have stripped it down again, found excessive oil ring gap .035". I had restricted the oil hole in the bottom of the barrel previously this did improve things. I am now going to seal the oil hole, fit a new set of rings and try again. The piston skirt will pick up plenty of lubrication from the flywheel splash. Also read on here before of others who have also sealed this hole. Another reason could be an excessive sump oil level, my oil pump scavenges OK and it would be difficult to lower the working level.

Will let you know how it goes, the blue haze is one fault I do not wish to accept. These old Nortons certainly keep you thinking.

Best regards

Paul

Hi Albert

How was the Rally, I did the International Rally last year in Spain Colombres on the very ES2, dont want to talk ill of the bike as it did not miss a beat in almost 2000 miles covered, but it consumed a fair amount of oil.

Update on my issue, I blanked the oil hole, put a new set of rings in, rebuilt and unfortunately very little improvement if any. Had a rethink and I recalled being told awhile ago about the crankcase breather, (I think it was Mike Pemberton from Push rod performance) mine has (had) a very small ball bearing non return valve in it approx 3/16" it was recommended that I remove it, in desperation I gave it a go. Started it up and so far clear blue skies in my wake. It makes sense to me if the crankcase breathing is restricted any pressure will push oil up past the oil ring etc. I have yet to view the bike underway from behind but I have seen nothing in the mirror or had a whiff of anything in a trailing wind. I do believe I have sorted it.

I have also just completed the rebuild of a 1948 AJS 500 single, there is a non return valve in the breather of that engine though a much bigger disc valve, it burns beautifully, with not a hint of the blue haze. I hope to take the Norton out again this weekend weather permitting, I will keep you posted.

Best regards

Paul

Do the owners of pre 51 sidevalves have these problems?Regards John.

Hi.

With regards to the 'oil pressure control valve'. Quote from the Manual:

The oil pressure control valve is a spring loaded ball, and acts as a safety valve in the oil circuit. When the pressure of the oil lifts the ball from the seat, the oil passes the ball and is sprayed upon the timing gears. When the engine is assembled at the Works, the valve ball spring adjusting screw is screwed home and released 1 & 1/2 threads. This is the only adjustment in the oiling system and it is not advisable to remove the ball unless it is suspected that it is sticking or not seating.

If this ball is sticking or incorrectly adjusted (screw too tight) it would result in excess oil being fed to the barrel. Screwing it 'in,' as has been suggested, increases the amount of oil to the barrel.

Other possibilities would be -a dodgyhead gasket leaking into the combustion chamber from the drain from the valves (I lap my cylinder head to the barrel).

The pump - if someone has 'faced' the mating surface (to the crankcase)of the oil pump body and not taken a similar amount off the edge of the brass plate of the pump. With your pump assembled, check with a steel rule across the mating surface holding it up to the light to look for a gap. This was the cause of my Dommi's wet sumping!

I assume you have checked for valve guide wear and sticking oil control ring. The one time my ES2 smoked it was due to the slot in the piston, behind the oil control ring, closing up and impinging on the ring. Check you have the right oil control ring - two types were used on the singles 1/8" & 3/16".

As regard leaks from the timing case mentioned by others - clean out your screw-holes - make sure the screws are actually tightening on the case. It cured myleak and I couldn't believe the anmount of crud in there!

My own ES2's oil consumption is negligable and my oil pump has eaten the remains of at least two big-ends!!!

Regards.

Ian.

Hi.

With regards to the 'oil pressure control valve'. Quote from the Manual:

The oil pressure control valve is a spring loaded ball, and acts as a safety valve in the oil circuit. When the pressure of the oil lifts the ball from the seat, the oil passes the ball and is sprayed upon the timing gears. When the engine is assembled at the Works, the valve ball spring adjusting screw is screwed home and released 1 & 1/2 threads. This is the only adjustment in the oiling system and it is not advisable to remove the ball unless it is suspected that it is sticking or not seating.

If this ball is sticking or incorrectly adjusted (screw too tight) it would result in excess oil being fed to the barrel. Screwing it 'in,' as has been suggested, increases the amount of oil to the barrel.

Other possibilities would be -a dodgyhead gasket leaking into the combustion chamber from the drain from the valves (I lap my cylinder head to the barrel).

The pump - if someone has 'faced' the mating surface (to the crankcase)of the oil pump body and not taken a similar amount off the edge of the brass plate of the pump. With your pump assembled, check with a steel rule across the mating surface holding it up to the light to look for a gap. This was the cause of my Dommi's wet sumping!

I assume you have checked for valve guide wear and sticking oil control ring. The one time my ES2 smoked it was due to the slot in the piston, behind the oil control ring, closing up and impinging on the ring. Check you have the right oil control ring - two types were used on the singles 1/8" & 3/16".

As regard leaks from the timing case mentioned by others - clean out your screw-holes - make sure the screws are actually tightening on the case. It cured myleak and I couldn't believe the anmount of crud in there!

My own ES2's oil consumption is negligable and my oil pump has eaten the remains of at least two big-ends!!!

Regards.

Ian.

Hi Albert.

I dispensed with the aluminium head gasket years ago. They always blew - usually across the stud holes. I just use a spot of RTV to stop anyleakage from the rocker-box drain holes.

Regards.

Ian.

Hi!

I made a head gasket out of 0.020" soft copper sheeting for my 19s, so far (Several years now) it hasn't leaked, at least not there.

Regards,

Albert

Worn valve stems and guides would be at the top of my list if I looking for causes of smoky exhaust,I have replaced both in my es2 as a matter of course last time the head was off.If I was worried about smoke I would also fit stem seals.The intake valve is subject to manifold depression,and will pull in any oil that gets on the top of the guide.Regards John.

You can buy them at any auto parts store,but you might have to machine the top of the guide to get them to stay put.I allways use Perkins guides that are already machined for seals,but they are a plain cylinder and have no flange,so you must make provision for some location of the lower spring seat.I also make the valves out of good quality industrial ones,with hardchrome stems.You might be interested to know that BSA Goldstar exhaust valves had Nimonic 90 heads and hardened alloy steel stems, a far cry from the bike stuff you usually get today made from soft stainless.Nimonic was one of the socalled space age superalloys of the fifties used in gas turbine blades.Regards John.

Also, I dont use seals on the exhaust,backpressure prevents oil from running down the stem.Regards John.

Hi Albert

I know this is an old posting, but did you solve the problem? My '51 ES2 smokes a lot at start up and tickover, once I pull away it clears fairly quickly and I'm told it isn't as noticable once I'm on the move. I have done about 1800 miles on it since new valve's, guides, piston, rebore etc so it should be pretty well run it! I have seals on the valves so I'm pretty sure its the bore that is the problem.

Is there anyway of checking the oil pressure? I'm reluctant to solve the problem by blocking up the feed to the bore...

I have just completed 400 miles in 2 days on it and the oil consumption was considerable, as I plan to use this as my 'touring' bike for more of these rallies and longer runs I would like to solve the problem, or at least reduce it! I dont want to be carrying gallons of oil with me!

I am running it on straight 40 oil.

Any pointers would be great

Andy

Hi Albert

My ES2 is all newly assembled with new piston, rings, rebore, valves and guides. I've just got back from the NEC with the bike and its is unlikely to be used again until the spring, I will pull it appart when I get the chance and see what I can find.

Thanks for your reply

Andy

Hi Albert

I've had a morning in the workshop and taken the barrel and head off for a measure up. The piston to bore clearance are as expected but the ring gaps are huge! I'll order some new rings on Monday and put it back together with the oil feed blocked off. Fingers crossed it'll go back together over the Christmas break and be ready for 2015!

Only other question is what should the ring gap be? I have looked in 2 books and seen 2 different figures!

Andy