We discussed the issue new engine start-up on the Brit Iron list
regarding british motorcycles, and there was quite a bit of iconoclastic
information expressed and well-defended. Follwing is an imperfect
summary:
- do not hone the bores unless you go to oversize pistons
^^^
- use assembly lube on all bearing surfaces (of course)
- assemble the engine with dry pistons and bores
^^^^^^^^^^^^^^^^^^^^^^
- use non-detergent or lower-grade detergent monograde oil
- start it up and follow the drill outlined in the previous post.
The reason for not honing is rooted in the belief that the new rings
will seat into the bores anyway, and you simply are removing iron that
would provide some additional wear (you are opening the bores further
with a hone). Of course if there are serious ridges, scores, tapers,
etc., they probably will mandate a rebore and subsequent hone.
The reason for the dry bores and pistons is to assure a quick seating
(minimize the blow-by, hot spots, etc.) Today's oils are so good, that
folks are having a difficult time getting the rings to seat in properly,
and apparently if they don't seat in rather quickly, it becomes very
difficult to get them to seat properly due to wear patterns, glazing,
ridges, etc.
I know the no-hone, dry bores will raise a lot of doubts (it does seem
almost sacrilegious), but some engine builders would even throw bit of
boraxo in front of the carb to help the rings to seal quickly (there are
all kinds of variations on what type of powder you could/should use to
do this).
Now, I don't expect anybody to take my word for any of this (the dry
bores/no hone goes against most everything I have done/known for 20
years), but they convinced me.
My next rebuild will not be honed (assuming there is not a need for a
rebore), I will assemble the bores dry, and I'll use a gallon of the
cheapest 30 weight I can find for the first few hours of running.
Don the nomex and let the flames begin....
shook
74 TR6
73 V7 Sport
72 B50SS
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