motor still smokes

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JimC said:
If you want the rings to seat, keep the oil under the bench when you assemble the rings and pistons. Make certain the cylinders are oil free, too. Dry is the word. If you don't believe me, talk to any competent engine builder.
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:roll: :roll: DRIBBLE :shock: :shock:
 
So Splatt, tell us how it's to be done. Give us the benefit of your expert knowledge.
 
JimC said:
If you want the rings to seat, keep the oil under the bench when you assemble the rings and pistons. Make certain the cylinders are oil free, too. Dry is the word. If you don't believe me, talk to any competent engine builder.
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JimC would you be so kind to explain us (myself and a few other incompetent engine builders) why we built all those (non smoking) engines wrong to have put some oil on the rings instead of dead dry :?:
 
I, too, was a believer in using oil on the rings for assembly. This was back in the sixties. By the nineties I heard of rings not seating, I'm talking Nortons here. Sometime in the seventies I had the pleasure of visting with C.R. Axtell in his shop. It was there I first learned of dry ring assembly. I more or less forgot about it until I heard more and more Nortons not seating new rings. I'm speculating here, but I think it's because of the much better oils available. Lately, I spoke to Leo Goff. He swears by the dry ring assembly route. Vern Funeston (sp?) is another who agrees.

Nortonspeed, I never said you can't get rings to seat using oil. Nor did I infer those who used oil when assembling rings were incompetent. If you consider yourself to be so, so be it.
 
hi all,in my opinion theres no right or or wrong way, wet or dry, depends how long you want to run the engine in {break in] assembleing dry gives you the quickest break in period , by the time the oil has got to where it needs to be the rings and bore are broken in,probably less than a minute. race engine builders dont run the motor for a 1000 miles to make sure the bores are bedded in they assemble dry for more or less instant break in
 
I have been here...Smoky running, It turned out to be inlet valve guides, I machined down the guides and fitted ford cosworth seals..Then drilled a drain hole between the inlet vales...I dont think the 1/8 hole in one corner is not good enough...connect the new drain to a tee branch. Les Emery recon's its a standard race mod to drain the head. anyway it stopped the smoke...one other thing...if the guide hole is scored ,it's another entry for oil into the cylinder..good luck! I assume you have the correct rocker spindle's with the small holes?
 
JimC said:
I, too, was a believer in using oil on the rings for assembly. This was back in the sixties. By the nineties I heard of rings not seating, I'm talking Nortons here. Sometime in the seventies I had the pleasure of visting with C.R. Axtell in his shop. It was there I first learned of dry ring assembly. I more or less forgot about it until I heard more and more Nortons not seating new rings. I'm speculating here, but I think it's because of the much better oils available. Lately, I spoke to Leo Goff. He swears by the dry ring assembly route. Vern Funeston (sp?) is another who agrees.

Nortonspeed, I never said you can't get rings to seat using oil. Nor did I infer those who used oil when assembling rings were incompetent. If you consider yourself to be so, so be it.
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First of all I didn't ask you WHO agrees the 'dry ring method' but WHY we should follow this method (refering to a technical explanation) :!:

Like you suggested ANY competent engine builder assemble rings dry, well I (and probably a few other engine builders) don't so we can not name ourselfs competent, can we :?: :twisted:
 
A Ducati 750 GT did a similar thing, at first start up.
Removed heads and cylinders, (jugs) new rings etc checked everything, all good. Still smoked.
Dismantled again, checked and measured, re assembled. Still smoked.
Dismantled again,,,,,,

By chance the exhaust was leaned vertically against a bench,, and oil ran out of it !!!!!!!

The oil was in there from the first set of badly installed rings. And every time after that the engine was good, it was the oil laying in the pipes that was burning !!!!!
Washed the pipes out with petrol------- no more smoking !

Worth a look ?????
graeme.
 
JimC said:
If you want the rings to seat, keep the oil under the bench when you assemble the rings and pistons. Make certain the cylinders are oil free, too. Dry is the word. If you don't believe me, talk to any competent engine builder.
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The very well regarded BMW mechanic doing the reassembly of my airhead explained first start. . . Assemble dry. Start. Run up to 3500 RPM and hold for 40 seconds. Said he doesn't like the owner in the shop when he does it - freaks 'em out. :shock:
 
I just went back and read norton3 problem, this is the way I am understanding this he blew a head gasket and rebuilt the motor and it still smoked,
Was it smoking before you blew the gasket,if not why rebuild? Theres something about this problem I just dont understand.
 
Nortons3, have you taken it for a good long ride after assembly? Sometimes the running in and settling down period can be longer than at other times. If it smokes as much after a couple of hundred miles I'd say you have a problem, if it smokes after 20 miles ride it some more.
 
From my humble self; As allready stated ; I had a smokey engine...I removed the rear rocker cover and started the engine..It took a very little time for the space around the inlet valves to fill up and cover the guide tops. You will hear a girgle in the right ride,,,it's the return oil trying to get down the drain oil...i say trying because the crankcase acts as a pump....on the up stroke it sucks "some" oil down the small hole,,then when the pistons desend the pressure force's the oil back. So there is a" tug o war" between strokes...Doubt this? then try it! The new norton valve seals when hot got all floppy. Ford cosworth seals with spring bands cured the problem FOR ME! THIS MAY NOT BE WHY YOURS SMOKES. MANY YEARS AGO I WAS ADVISED NOT TO OVER STRAIN OPENING THE RINGS. They can be "Bent" once taken behond there modulas of elasticty they are never round again....i use three feeler gauge blades to slide the rings over the pistons. ONLY FOOD FOR TOUGHT...BEST REGARDS JOHN
 
[qNo the motor did not smoke befor the rebuild. As stated, the reason for the rebuild was a piece of the steel fire ring scored the left bank piston and cylinder wall, thus the rebuild. uote="mcns"]I just went back and read norton3 problem, this is the way I am understanding this he blew a head gasket and rebuilt the motor and it still smoked,
Was it smoking before you blew the gasket,if not why rebuild? Theres something about this problem I just dont understand.[/quote]
 
The return oil hole was checked on the first tear down and rechecked again on one of the other tear downs. As for the valve seals I used the standard seals, I,ll try the cosworth ones. Where can one purchase these. Thanks for your time!!
john robert bould said:
From my humble self; As allready stated ; I had a smokey engine...I removed the rear rocker cover and started the engine..It took a very little time for the space around the inlet valves to fill up and cover the guide tops. You will hear a girgle in the right ride,,,it's the return oil trying to get down the drain oil...i say trying because the crankcase acts as a pump....on the up stroke it sucks "some" oil down the small hole,,then when the pistons desend the pressure force's the oil back. So there is a" tug o war" between strokes...Doubt this? then try it! The new norton valve seals when hot got all floppy. Ford cosworth seals with spring bands cured the problem FOR ME! THIS MAY NOT BE WHY YOURS SMOKES. MANY YEARS AGO I WAS ADVISED NOT TO OVER STRAIN OPENING THE RINGS. They can be "Bent" once taken behond there modulas of elasticty they are never round again....i use three feeler gauge blades to slide the rings over the pistons. ONLY FOOD FOR TOUGHT...BEST REGARDS JOHN
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Yes I have thought of that, so I removed the header pipes from the head and started it up and ran it for a while, still smoked. Thanks for you time
GRM 450 said:
A Ducati 750 GT did a similar thing, at first start up.
Removed heads and cylinders, (jugs) new rings etc checked everything, all good. Still smoked.
Dismantled again, checked and measured, re assembled. Still smoked.
Dismantled again,,,,,,

By chance the exhaust was leaned vertically against a bench,, and oil ran out of it !!!!!!!

The oil was in there from the first set of badly installed rings. And every time after that the engine was good, it was the oil laying in the pipes that was burning !!!!!
Washed the pipes out with petrol------- no more smoking !

Worth a look ?????
graeme.
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No it did not smoke befor the rebuild. The reason for the rebuild is a piece of the steel firering scored the left bank piston and cylinder wall, thus the rebuild. Thanks for your thoughts.
mcns said:
I just went back and read norton3 problem, this is the way I am understanding this he blew a head gasket and rebuilt the motor and it still smoked,
Was it smoking before you blew the gasket,if not why rebuild? Theres something about this problem I just dont understand.
Click to expand...
 
Yes, the ring gaps on the jap were quite excessive. The three piece oil rings were around .022and the top rings were around .015. The replacement one piece oil ring was .012 as were the top rings. I thought I had found the problembut it still smoked but not near as much. Thanks for your thoughts
sidreilley said:
Was the end gap checked on the rings?
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I ran the engine for several hours after each tear down. The end gaps were installed by the manual, so that shouldn,t be a problem. Thanks for your time.
nortonman70 said:
How many hours was the motor run before pulling it apart? Rings need time to bed in so the smoking could be the result of first few starts and all the oil in the cylinders from fitting. I assume of course you used oil to fit the pistons in the jugs. Sounds like you looked at all the possible suspects. Did you ensure the ring gaps were aligned about 120 degree's apart?
Cheers
Steve J
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Cosworth valve seals ...ford performance shops will get you some....you will have to turn the guide tops down.When correct they are a snug fit. History...i rebuilt a commando 15 years ago...rebore.new pistons valves etc.....i took her out for a blast. I noticed a haze of blue smoke on one side...that got worse as the miles went by...i found a inlet valve seal had popped off....i replaced it and all was well. :) I replaced it because it felt loose when pushed back on..Cosworth have a metal band that holds the rubber in place.....far better. But you could have any number of cause's...smoke in the exhaust......nasty to find without step by step investigation. So heres a start....when you have had a smokey run ..have a look down the inlet ..sometimes you can see the valve back/seat wet,sure sign the seals are letting in...and there is loads of depression on them when the throttles snapped closed!. regards John
 
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