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rebuilt engine leaking oil....
#21
Finally found the problem after pulling the flywheel...
   
   
   

Lets hope with a modern seal we're back in business...
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#22
Isn't the rear main supposed to be a roller bearing? (or am I having a senior moment?)
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#23
Er, normally, yes.
Just check, there’s supposed to be an oil drain hole at the bottom of the steel bearing housing. It’s important that the carrier is fitted the right way up because it will go the wrong way. I only mention it because I can’t see it in your photograph.
Alan Fairless
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#24
Possibly someone knows something I don't (highly likely!) but that ball race would worry me far more than any oil leak. Next thing I would do is find out what the bearing arrangement is at the front end.
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#25
I run a ball race in the rear bearing of my engine, but that's in conjunction with a very carefully fitted flywheel.
The objective is to retain the axial movement of the crank at the rear bearing, not the front lip. However, the grinding of the spacer that goes between the flywheel and bearing is a job where a couple of thou is important. It's a Frank Hernandez suggested mod.

Charles
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#26
Where is Frank. I’ve not heard of him in ages.
Alan Fairless
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#27
(06-05-2024, 12:30 PM)Charles P Wrote: I run a ball race in the rear bearing of my engine, but that's in conjunction with a very carefully fitted flywheel.
The objective is to retain the axial movement of the crank at the rear bearing, not the front lip.  However, the grinding of the spacer that goes between the flywheel and bearing is a job where a couple of thou is important. It's a Frank Hernandez suggested mod.

Charles

Using a ball race in the rear main bearing is a modification I have considered for years, but apart from sourcing the bits, haven't yet got around to it yet!
It would be at its most beneficial in a 3 bearing engine, where it would isolate the thin center webs from the bending forces that surely occur when depressing the clutch pedal puts a heavy axial load over the full length of the crank. Leaving the front bearings floating (as in a modern plain bearing engine) is surely kinder to the crankshaft, particularly under normal i.e. non racing conditions. The gyroscopic loads on the flywheel might be a problem when cornering, but only slightly more than with  a roller race.
We'll never know if we don't try it... Here's to a healthy discussion!
Bob
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#28
(06-05-2024, 02:57 PM)Bob Kneale Wrote:
(06-05-2024, 12:30 PM)Charles P Wrote: I run a ball race in the rear bearing of my engine, but that's in conjunction with a very carefully fitted flywheel.
The objective is to retain the axial movement of the crank at the rear bearing, not the front lip.  However, the grinding of the spacer that goes between the flywheel and bearing is a job where a couple of thou is important. It's a Frank Hernandez suggested mod.

Charles

Using a ball race in the rear main bearing is a modification I have considered for years, but apart from sourcing the bits, haven't yet got around to it yet!
It would be at its most beneficial in a 3 bearing engine, where it would isolate the thin center webs from the bending forces that surely occur when depressing the clutch pedal puts a heavy axial load over the full length of the crank. Leaving the front bearings floating (as in a modern plain bearing engine) is surely kinder to the crankshaft, particularly under normal i.e. non racing conditions. The gyroscopic loads on the flywheel might be a problem when cornering, but only slightly more than with  a roller race.
We'll never know if we don't try it... Here's to a healthy discussion!
Bob


There are a lot of theoretical benefits but you cant get away from the fact that a ball race has less load capacity than a roller.
If you have a desire to tour the world with your family, a la Dunford, then it may not be the mod for you. That said, most rear rollers seem to wear through the gentle misalignment caused by crank whip and corrosion, rather than through excess mileage. 
Cue Tony Press with an educated view of the bearing choice!

PS - mine has been like this for a decade or so
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#29
If the surface of the flywheel boss is poor a modern oil seal won't work.
Jim
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#30
(06-05-2024, 10:54 AM)Alan Wrote: Er, normally, yes.
Just check, there’s supposed to be an oil drain hole at the bottom of the steel bearing housing.  It’s important that the carrier is fitted the right way up because it will go the wrong way.  I only mention it because I can’t see it in your photograph.
The reverse scroll rear bearing cover normally holds the oil in unless as said the oil drain hole isn’t at the bottom of the housing.Why has it got a ball race at the rear,is it a wheel bearing?
Stuart Rolt used to use two self aligning double row ball races but with this arrangement how does the crank grow and shrink in length when whipping ?
If indeed the oil has come out of the back of the crank you must have had a bell housing and clutch full of oil ?
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