Where is All The Oil Going?

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In an attempt to eliminate the obvious, I did a dry compression test. Warm engine with the throttle open, 136 lb of cylinder pressure on both sides.
 
Dan1950 said:
In an attempt to eliminate the obvious, I did a dry compression test. Warm engine with the throttle open, 136 lb of cylinder pressure on both sides.
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Seems good. I'm getting 150 psi after a first re-bore and bedding in.
 
Dan1950 said:
What is the compression ratio?
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Dunno, nothing done other than stock head, stock sized kibblewhite valves/guides and 20 thou oversize hepolite pistons.

Might it be compression kicking technique? I had giver 'er a good 5-10 kicks each side, throttle wide open, warm engine before guage stabilized at 150.
 
Tornado said:
Dunno, nothing done other than stock head, stock sized kibblewhite valves/guides and 20 thou oversize hepolite pistons.

Might it be compression kicking technique? I had giver 'er a good 5-10 kicks each side, throttle wide open, warm engine before guage stabilized at 150.
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I stopped at 6 kicks. At 8.5:1 I thought 136# was pretty respectable.
 
Your post leaves me with more questions than answers.

1) New rings with or without an over bore makes me wonder if the skirt clearance and/or ring gap was checked.

2) If the valve seals that were installed were OE or similar POS you should give strong consideration to going with the best you can find. When Comnoz did my head over he installed Kibblewhites with a heavy collared clamp which keeps the seal tightly in place n the guide and a spring that keeps the seal making good contact to the valve stem.

3) Rocker shafts installed 180 degrees from where they should be.

4) if the top-end is new it may require more miles to bed in; this Forum is loaded with advice on how to do this; read them all and pick the ones that have a lot in common and distill them, you'll be weeding out the posers.

Best.
 
kerinorton said:
Until Dan gets someone [ who knows what he is doing ] to ride behind him on a long ride, it's all a guessing game. Guessing games are a waste of time.
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Or a quick check under the cover, could have done that in the time it`s took to read this thread.
 
RoadScholar said:
Your post leaves me with more questions than answers.

1) New rings with or without an over bore makes me wonder if the skirt clearance and/or ring gap was checked.

2) If the valve seals that were installed were OE or similar POS you should give strong consideration to going with the best you can find. When Comnoz did my head over he installed Kibblewhites with a heavy collared clamp which keeps the seal tightly in place n the guide and a spring that keeps the seal making good contact to the valve stem.

3) Rocker shafts installed 180 degrees from where they should be.

4) if the top-end is new it may require more miles to bed in; this Forum is loaded with advice on how to do this; read them all and pick the ones that have a lot in common and distill them, you'll be weeding out the posers.

Best.
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There has not been any engine work performed on this bike that I know of in the last 25 years. I bought the bike last September and it has thorough records and documentation back to 1997 kept by the 2 previous owners.

I recently had the carburetors removed to allow the engine to be rotated up to facilitate gearbox removal. That is when I noticed that the right intake valve had considerable carbon buildup while the left valve was spotless. There is also evidence that the right cylinder is running cooler than the left as indicated by a slightly blue tint on the left exhaust pipe while the right is a pale straw color. Curiously, the spark plug from the left cylinder shows a slightly rich A/F condition while the right shows a near perfect plug color. You would think that the opposite would be the case given the indication on the exhaust pipes.

Where is All The Oil Going?


I have ordered a rocker shaft pulling tool and will fabricate a spring compressor to do the valve stem seals in situ. I know of the "rope trick" and I am confident that I can perform this task. I have also ordered the red Viton stem seals from Steadfast. If I can reduce the oil consumption to a reasonable level. I will ride the bike this summer and go into the engine next winter if warranted.

If I have to pull the head, I want to go the rest of the way to raise compression slightly with a cam change that will reduce cylinder pressure at low RPM to allow easier kick over and mitigate any octane related issues that might arise.
 
FWIW, exhaust valves can also allow oil into the combustion chamber due to the effect of the outgoing exhaust gas generating a vacuum that can suck oil past the valve stem/guide. This is why modern engines have seals on both valves (or "all" valves if appropriate). When I bought my new 1992 Ducati 900SS, it came with only intake seals. About a year after I bought it, Ducati came out with a service bulletin to add exhaust valve seals...at owner expense! It is common, and has been for many years, to add exhaust seals to engines that were not fitted with them originally.
 
MexicoMike said:
FWIW, exhaust valves can also allow oil into the combustion chamber due to the effect of the outgoing exhaust gas generating a vacuum that can suck oil past the valve stem/guide. This is why modern engines have seals on both valves (or "all" valves if appropriate). When I bought my new 1992 Ducati 900SS, it came with only intake seals. About a year after I bought it, Ducati came out with a service bulletin to add exhaust valve seals...at owner expense! It is common, and has been for many years, to add exhaust seals to engines that were not fitted with them originally.
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Well, the indication is that there is something (most likely oil) causing a buildup of deposits on the right side intake valve yet nothing on the left valve. Cylinder pressure is the same for both cylinders.

Any opinion on what might be casing that?
 
"Well, the indication is that there is something (most likely oil) causing a buildup of deposits on the right side intake valve yet nothing on the left valve. Cylinder pressure is the same for both cylinders.

Any opinion on what might be casing that?"

As has been stated, the most likely cause deposits on an a valve is bad valve seals and/or excessive valve stem/guide wear.

If no work has ever been done on the bike, the valve seals are bad - that's a given. They will have work-hardened years ago. Of course, you could have bad seals AND excessive valve stem/guide clearance.

But a quart in 300 miles? I'm not sure that bad valve seals alone could do that! Frankly, if that much oil is being burned, whether it's rings/cyl walls or valve guides/seals, the bike should look like a mosquito sprayer going down the road! ;)

Do you have a chain oiler that might be over-enthusiastic? Some other way that oil could be leaving?

In any case, do the test where someone is following/observing for smoke.
 
MexicoMike said:
"Well, the indication is that there is something (most likely oil) causing a buildup of deposits on the right side intake valve yet nothing on the left valve. Cylinder pressure is the same for both cylinders.

Any opinion on what might be casing that?"

As has been stated, the most likely cause deposits on an a valve is bad valve seals and/or excessive valve stem/guide wear.

If no work has ever been done on the bike, the valve seals are bad - that's a given. They will have work-hardened years ago. Of course, you could have bad seals AND excessive valve stem/guide clearance.

But a quart in 300 miles? I'm not sure that bad valve seals alone could do that! Frankly, if that much oil is being burned, whether it's rings/cyl walls or valve guides/seals, the bike should look like a mosquito sprayer going down the road! ;)

Do you have a chain oiler that might be over-enthusiastic? Some other way that oil could be leaving?

In any case, do the test where someone is following/observing for smoke.
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It's cold and raining for the next few days. I'm only a few miles from Canada eh? I will have my son follow me as soon as the weather clears.

I'm wondering about the chain oiler comment as I did have oil spatter on the rear rim. Not a constant coating, but large spots of oil on the rim. No oil on the tire though.
 
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