Re: OIL LEAK

Unknown

I would query Geoff's figure of .0005".  The
rule of thumb I have always used is .001" per inch of journal diameter. 
Even if your bearings were somewhat worn I cannot see how that would contribute
to so much oil loss.  There is no pressure feed, just splash directed into
catchment channels.  Is your crankcase properly vented?  When you have
it running can you feel blowby coming out the oil fill opening?  The
primary vent is a screen inside the oil filler cap.  Later models
employed a substantial vent tube on the left side of the engine about 1-1/4"
diameter.  If you have only 1 psi or so of crankcase pressure the oil may
not return to the sump as it should as the collection ring is open to
atmosphere

 

Before you tear into it again I would try
slackening off the tappet covers, shove a pencil or small spacer between the top
of the cover and the block, and gently snug up the retaining bolts.  Do not
put the spacer at the bottom as the covers are designed to direct splash and
mist back inside at the bottom.  After doing this take it for a drive again
and record results.

 

This is surely a puzzle.

Karl

 

 

 

 

----- Original Message -----

From:
Robert Frankcom

To: hudsonsupersix16-29@yahoogroups.com

Sent: Friday, February 26, 2010 11:29
AM

Subject: [HSS] OIL LEEK

 

Karl and Gregg,
We'll I think Martyn and you are right. I've just
driven 40 miles in 1 hour and used nearly one and a half UK pints,
and it is almost certainly coming out of the rear main bearing.
You say the
main should have a tolerance of only 0.0005'', whereas the big
ends should be 0.002''  (from an email late last year) or have I
misunderstood what these tolerances actually mean
Is the tolerance of
the mains at 0.0005 the total, or 1/2 the total? Likewise is the total
tolerance of the big ends 0.002'' or 0.004''? (I would have thought would have
a total of 0.002'')
Assuming the mains should have a total of 0.001,
and assuming that when I took my reading their was no
distortion of the crank because of its weight and the weight of the flywheel
and clutch, my reading of 0.0025'' would equal a total of
0.005''. So if I take out 0.002'' of shims either
side, I will in effect only cure the bottom half of the bearing. If I
take 0.004'' out of the shims, the bearing cup would be trying to force the
crankshaft up out of line.
So I suppose I am asking what figures
should I use; is it practical to try and fix these tolerances
of mine in this way, or heaven forbid, is it a case of new white
metal and in-line boring and all that that entails?
My mechanics manual
gives no info on this subject at all, is there a proper workshop manual and if
so how do I get one?
Hope you're not getting bored by all this, 
Robert