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ES2 Engine problems

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ES2 Engine problems

Posted by Dan Field at October 06. 2016

I'm looking for some inspiration/guidance!

I have two problems with my engine 55 ES2, one is oil getting into the combustion chamber and the other is a noise a bit reminiscent of a high mileage Ford pinto engine!

The bottom end was allegedly rebuilt before the bike was put away in the 90s, it has since had a rebore and was fitted with modded 16h piston. It has smoked excessively, esp when cold, since I bought it and got it going - compression is good and it runs without a head gasket, on removing the head there was oil on the top of the piston, about half a teaspoon. There was also oil in the ports.  The head has since away to mike P, and has new valves guides, valve seats and springs etc. There is no longer any oil in the intake port but there still is on the piston.  I was unsure about the piston so have just fitted a new Gandini piston, all in spec, and I was hopeful that this would solve the problem but alas no, it smokes as much as ever! Primary and mag chains are adjusted properly.

I thought the oil might be because of wet sumping, but I tried draining the sump before starting and that made no difference either.

Which brings me on to the noise, this seems to be at the top end but it's difficult to say. When I removed the 16h piston to my concern I could see that it had been just hitting the head because the chamfer on the piston crown was too small. There is no evidence of the new piston hitting but the noise is still there. I've checked the push rods, they are ok. And nothing is lose. My disadvantage is that I don't know how noisy these engines are normally, mine is certainly lovely and quiet when cold, it takes about a minute for the noise to appear.

i can only think big end/Rod damage as a result of the piston touching the head but it seems to be higher than that. Do the cam bushes or followers suffer wear on these engines?

any thoughts?

Re: ES2 Engine problems

Posted by les_howard at October 07. 2016

Hi Dan....yes it does seem a mystery.....but the top -end noise might be the rockers spindles are loose in the rocker cover and when it warms up there is clearance enough to let them move up and down.....Also check that the rockers are not touching the inside of the rocker cover, perhaps the rockers are incorrect but only slight grinding needed if this is so to achieve clearance.

I always use a long screwdriver as a stethoscope to narrow down engine noises and to make it more effective either block the opposite ear with a finger or wear a tight fitting ear plug. This way only sounds from the stethoscope enter the ear making it much more effective.

As for the oil, well you've covered all the head possibilities, unless the oil is travelling across the head joint directly into the bore, in effect head gasket leak. OR the new piston has not yet bedded in....also use at least 40 weight oil.

Les

Re: ES2 Engine problems

Posted by nicholas_reeves at October 07. 2016

Hi Dan, I had a similar smoking problem with my 1935 ES2. I had the head rebuilt,again by Mike P. I also sent him the Barrel,Piston and Rings. He found that the ring gap wasn't only just to big but instead of the rings being gapped at an angle they had been filed straight.The piston,strangely was found to be slightly tight in the bore,even though it wasn't a new piston.Anyhow,he replaced the rings,honed the barrel so the piston wouldn't be tight and the rings would bed in properly.I should point out the piston was only a tiny bit tight. I also made sure the bearing in the crankcase breather was free as per Mikes surgestion.Having put it all back together,it runs perfectly.I have done 400 miles of running in ie not labouring the engine,reving hard,and not holding it at a constant speed etc and not the slightest hint of smoke.Before it was literally like a bonfire coming out the exhaust,you couldn't use it on the road it was that bad.Good luck hope this might help.Regards.Nick.

Re: ES2 Engine problems

Posted by nicholas_reeves at October 07. 2016

Dan.Sorry forgot to add that Mike also lapped the head to the barrel for me too as mine also has no head gasket.

Re: ES2 Engine problems

Posted by Andy Marks at October 07. 2016

Hi Dan

Your oil problem sounds very similar to mine a while back. The responses on this thread where very helpful and all seems ok now. I have done about 150miles with the rubber o-rings on the stems and the correct size washers on the union bolt, as per the drawing Barry posted. It's using virtually no oil, there are no leaks and it doesn't seem to be smoking at all. It's definitely worth checking those sealing washers!

Good luck

Andy

Re: ES2 Engine problems

Posted by Paul Knapp at October 07. 2016

Hi Dan I also had the same excessive oil burning problem after a total engine overhaul. When I removing the rocker box, I noticed it was dripping with oil and even though I had reamed the valve guides  on the minimum clearance  side, when removing the valves, a very obvious bead of oil had collected around the underside. I discovered the excessive oil was flooding down the inlet guide and burning off on the piston crown and blowing out the exhaust. I removed the banjo bolt feeding the rockers and soldered up one of the two inlet holes under the banjo effectively halving the oil flow. Instant improvement, no more smoke nor oily exhaust pipe. I also machined up a larger bore breather behind the primary inner cover, though I don't know how much effect this had as the original had performed apparently OK previously.

Paul

Re: ES2 Engine problems

Posted by richard_cornish at October 07. 2016

Hi Dan,

  Your engine seems to have the symptoms of excessive piston to bore clearance. Can you remember the measurement when you built the engine? It should be 0.005"/0.006" ( 0.12/0.15 mm ) measured at the bottom front or back of the piston. If the gap is more than 0.015" ( 0.4 mm ) this will be excessive and cause piston slap which may well be the noise your engine is making. Compression will be good because the excessive oil will make a hydraulic seal when you kick it over. If this is the case you will also have excessive crank-case pressure which can force oil up the push-rod tubes into the rocker box. The diameter of the two oil feed holes in the rocker box banjo bolt should only be about 2 mm to limit the oil supply.      Regards,  Richard.

Re: ES2 Engine problems

Posted by Dan Field at October 08. 2016

Thanks guys, My head was sorted by Mike and runs without a gasket, although I have tried it with one so don't think the problem is there. Also there is no oil in the inlet port

I'll try removing the valve on the crankcase breather but have checked that it was working ok.

I would have expected piston slap to be worse when cold but am beginning to think it might be piston clearance, it was 8-10 thou which is higher than I would have liked but tolerable, esp as i still might take it on the track once to see how it goes! However I don't think I measured it all the way up the bore and wonder if it isn't parallel.

I tried a screwdriver stethoscope but couldn't identify the noise!

Re: ES2 Engine problems

Posted by Dan Field at December 02. 2016

Ok an update, I reamed out the small end bush and fitted a new gandini piston, but it still clatters when warm and burns a serious amount of oil.

i took the head off and found  this https://imageshack.com/i/plf9m68oj

I took the barrel to my engine who confirmed that bore is good and recently rebore, the ring gaps are also all ok.

so the question is what's the problem? Once I get it back together I'll remove the crank case breather and see if the cases are getting compressed other than that I'm stumped!

Dan

Re: ES2 Engine problems

Posted by Barry Carson at December 02. 2016

 

 

Hello. like i said before without the head on with the piston back in the bore clamp the barrel down.  collect the oil from rocker feed into something. clean all the oil out of the bore and off the piston then kick the engine over about 30 times and observe if any oil is being left at the top of the bore. noise wise on mine before it was re lined the back pressure would force the valve lifter to clack being pushed in and out against the alloy on the rocker box i thought it was piston clacking at the time.  Baz              

just found a photo of mine

 

 

 

Attachments

Re: ES2 Engine problems

Posted by robert_tuck at December 03. 2016

Block off the oil feed to the head,if after a few miles the smoke stops you know its NOT the piston.

Re: ES2 Engine problems

Posted by Dan Field at December 03. 2016

Robert, I'm pretty sure it's not the head, Mike P has worked his magic on that and it has new valves and guides, plus there's no oil in the inlet port.

Barry your problem looks very similar, my piston is new and the clearance is apparently 5-7 thou on a recently rebore, measured properly by Dave Massam, why did you need to have your barrel relined, was it wear? Your piston looks new.

Dan

Re: ES2 Engine problems

Posted by john_holmes at December 03. 2016

Its a simple and quick test to block the head feed, assumptions are worth nothing if wrong, even the best expert can make the odd mistake.

Re: ES2 Engine problems

Posted by Barry Carson at December 03. 2016

 

 

Hello.as i found out at the end of the day the bore had been honed to the next piston size not a good thing as i was told it was probably done with a cheap three leg honer because of how the bore had a mirror like Finnish.  in turn this effected the next size piston fitment it would have been out of spec so i decided to have it relined by SRM. Baz

 

 

 

Re: ES2 Engine problems

Posted by Paul Knapp at December 03. 2016

Well, having had EXACTLY the same problem after completely refurbishing  my ES2 engine several years ago. After swapping pistons, rings, making a much larger case breather valve , checking how much oil residue was in sump etc etc, I did notice upon one quick strip down after a run, that the inlet valve, when I popped it out and stood on the bench, that a very obvious circle (read puddle), of oil was gathering around the seating face, from the tulip (the port was dry).It was coming down the stem, I also noticed that the rocker box was very wet, evident when I sat it on the bench, and then lifted after a while to see how much oil had drained down.

I then soldered up one of the cross drilled holes in the feed banjo bolt for the rockers...............Instant success, no more smoky exhaust. Give it a go Dan, you have tried just about everything else. 

Paul

Re: ES2 Engine problems

Posted by robert_tuck at December 03. 2016

My 99 was getting too much oil on the plugs, but not enough to the rockers which were dry. the overoiling to the plugs solved itself after a number of spirited rides finally bedded the rings in after many years light use . Now its a pain to kick over ,the compression is not helping the sciatica. I fitted a jubilee sized banjo on the return to get more oil to the rockers,this brought back the overoiled plugs plus a puzzling tendancy for the tank to fill with mayonaze and the distributor to fill with oil. My thinking was that the oil was now circulating the engine and not bothering much with the oil tank!I am gradually reducing the tank restriction in steps till I get the head flow correct. The plugs are now ok ,the dissy seems happy,and the bike is performing like never before,except the clutch is now protesting about the power its handling. This is what classic ownership is all about. Involving ,it is.

Re: ES2 Engine problems

Posted by Dan Field at December 03. 2016

All food for thought, I've got new valves and guides and it's been fitted with the later narrower springs so it doesn't foul the rocker box. The drain holes are clear and running well. I doubt it's the head, but will try reducing the oil flow, but first I'll remove the one way breather, and do lots of kicking and see what that brings and then refit the head and try it with no oil to the rockers and see what happens as the smoking was almost instant.

dan

Re: ES2 Engine problems

Posted by Paul Knapp at December 04. 2016

Here is a the inlet valve I removed when the engine cooled down after a hour or so. I pulled it straight out of the guide and placed on bench in the position in photo after a smoky run. The oil was very evident  above the seat after I returned to the shed later in the day for more head scratching. The valve had been new and I had previously reamed the guide a tad on the tight side upon the initial full restoration.

 photo DSC03158.jpg

Re: ES2 Engine problems

Posted by philip_ham at December 05. 2016

Another thing that hasn't been mentioned is the oilway between the head and barrel.  Like other people I've had my 1955 ES2 improved by Mike P, in this work the oil way that drains the rocker box to the sump had a small oil seal (O ring) fitted into the head.  After putting the engine into my frame and test riding it I had an unusual noise, which I wondered if it was the dynamo bearings - but no.

After some investigation I found that this little O ring between the head and the barrel was badly deformed, thus allowing crankcase pressure to push oil out between the head and the barrel i.e. an external oil leak!  This was happening because the drain hole on the head was not in line with the hole in the barrel, so the little O ring was not sealing oil way and was partly blocking the drainage route.

Now this may not be the solution to the excess oil getting into the combustion chamber, but it's worth checking to see if this is causing the noise where hydraulic pressure is being released at the head / barrel joint.

I'm planning to remove the head an barrel over Christmas to see how to resolve the O ring problem, so may have more to report after this.

Philip

Re: ES2 Engine problems

Posted by Barry Carson at December 05. 2016

 

 

just wondering if the piston oil ring only fits one way and its upside down. Baz

 

 

Re: ES2 Engine problems

Posted by Dan Field at December 05. 2016

No noticeable oil leak at the head, but I'll keep it in mind, and I don't think the oil ring is fussy about which way it goes but will make sure before reassembly!

Re: ES2 Engine problems

Posted by paul_gerrard at December 06. 2016

Previously Dan Field wrote:

I'm looking for some inspiration/guidance!

I have two problems with my engine 55 ES2, one is oil getting into the combustion chamber and the other is a noise a bit reminiscent of a high mileage Ford pinto engine!

The bottom end was allegedly rebuilt before the bike was put away in the 90s, it has since had a rebore and was fitted with modded 16h piston. It has smoked excessively, esp when cold, since I bought it and got it going - compression is good and it runs without a head gasket, on removing the head there was oil on the top of the piston, about half a teaspoon. There was also oil in the ports.  The head has since away to mike P, and has new valves guides, valve seats and springs etc. There is no longer any oil in the intake port but there still is on the piston.  I was unsure about the piston so have just fitted a new Gandini piston, all in spec, and I was hopeful that this would solve the problem but alas no, it smokes as much as ever! Primary and mag chains are adjusted properly.

I thought the oil might be because of wet sumping, but I tried draining the sump before starting and that made no difference either.

Which brings me on to the noise, this seems to be at the top end but it's difficult to say. When I removed the 16h piston to my concern I could see that it had been just hitting the head because the chamfer on the piston crown was too small. There is no evidence of the new piston hitting but the noise is still there. I've checked the push rods, they are ok. And nothing is lose. My disadvantage is that I don't know how noisy these engines are normally, mine is certainly lovely and quiet when cold, it takes about a minute for the noise to appear.

i can only think big end/Rod damage as a result of the piston touching the head but it seems to be higher than that. Do the cam bushes or followers suffer wear on these engines?

any thoughts?

If there is no head gasket, the oil could be coming from the oil feed that comes up through the back of the barrel to the rocker box. Well there is one on my Model 18.

 

Paul Gerrard

Re: ES2 Engine problems

Posted by paul_gerrard at December 06. 2016

If there is no head gasket, the oil could be coming from the oil feed that comes up the back of the barrel to the rocker box. Well there is one on my Model 18.

Paul Gerrard

Re: ES2 Engine problems

Posted by brian_gore at December 06. 2016

Hi Dan.  Don't know if you have managed to sort the oil leaking into the cylinder problem.? I also have a 1955 es2  520cc short stroke motor which Mike P tuned about 12 years ago which I have done track days on and have been to the Isle Of Man 7 times ( oh and not hanging about.)   However. I have also experienced oil coming from between the cylinder head and barrel externally so I removed the head and found that the two small rubber rings had become hard and brittle allowing oil to be forced out so I replaced them following lapping the head in  ( no head gasket.) which solved the problem.

While I had the head an barrel off I drilled and tapped the crankcases and fitted a 1/4" breather in the same position as a Norton International which also seems to have helped this high revving engine.         

                              Brian Gore.

Re: ES2 Engine problems

Posted by Dan Field at December 06. 2016

Just got the barrel back this evening, so not fixed yet, bore has a clean bill of health and it's a new piston and rings, so that's not at fault either.  The head has been lapped so has no head gasket, but tried it with one and it made no difference. As far as I can tell there's no oil feed to the rockers only the two drain holes from the rocker box to the crank case.

To my mind it is most likely to be over oiling of the head or a pressurised crank case. I'll keep you posted. I might get some shed time this weekend.

no o rings in the head, I just rely on wellseal!

Any suggestions welcome!

dan

Re: ES2 Engine problems

Posted by les_howard at December 07. 2016

Quote:

Any suggestions welcome! dan

You are running it on 2 stroke petrol mix?.....Laughing

Les

Re: ES2 Engine problems

Posted by Dan Field at December 07. 2016

Damn never thought of that! Mind you if I did it would smell better as I use putolene castor oil in my race bikes!

Re: ES2 Engine problems

Posted by Dan Field at December 27. 2016

Having got the barrel back from the engineers I had a bit of spanner time today and re fitted the piston and barrel. Interestingly kicking it over with out the head on there is a surprising amount of draft coming from the head drain holes in the barrel. No obvious signs of oil pumping onto the top of the piston. But I've removed the ball from the one way crankcase vent just in case.  Inrefitted the head and used a syringe full of oil to test the head oil drain holes, they work fine.

But looking at the banjo it only has one very small oil hole so normally I'd say that was unlikely to be causing the over oiling, however, the banjo bolt is a very lose fit in the banjo, meaning that a large quantity of oil can pass around the bolt and into the top of the head?

Ill try running it with no oil supply to the head and se what happens.

Re: ES2 Engine problems

Posted by Andy Marks at December 29. 2016

Hi Dan

I am sure the problems I had with oil getting into the head and a smoking exhaust where caused by too much oil in the rocker box. The banjo bolt is quite a loose fit in the banjo but the washers on either side need to be tight on the bolt. I had oil running up the outside of the banjo bolt so the holes in it where doing nothing at all to regulate the flow. Fitted different washers and saw a huge improvement. I've attached a picture that was sent to me on another thread that made this clearer.

 

I also did some work on the breathing of the engine. I now have a 12mm pipe running to a read valve breather and going into a dump tank tucked up in front of the gearbox and out of sight once the primary chain case goes on. This also helps with the oil tightness of the engine, I presume by reducing the crankcase pressure. I also no longer have that annoying drip under the breather. Touch wood my engine is now oil tight apart from the odd drop from the timing chest breather. But next time I have the bike up on the bench I have an oil seal to fit behind the sprocket on the inlet cam so should hopefully solve that as well.

 

Now if only I could get the gearbox oil tight!

 

Attached are some pictures. Good luck

Andy

Attachments

Re: ES2 Engine problems

Posted by Andy Marks at December 29. 2016

And as I still don't seem to be able to load more than one picture at a time, here we go...

Excuse the rough soldering and paintwork, it was very much a case of lets just fit it and see if it works at this point, it does so next time its off I might tidy it up a bit.

Attachments
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