----- Original Message -----
From: Wayne Lee
To: net@lists.mv.net
Sent: Tuesday, May 31, 2005 8:49 AM
Subject: Re:Align Bore
To Clarify Further, Align Boring and Align Honing are 2 different procedures
that involve the
same setup indicating etc... I don't know what Crankshaft rub means but
mostly Align honing is for
honing less than .003" in most cases and Align Boring is anything greater
than that,most often with
a Sunnen Honing Machine which is an abrasive form of removing material in
contrast to boring
which cuts the material with a Boring Bar with carbide insert cutter. Either
procedure sets the foundation for Engine
building to insure concentricity and alignment of the Main Saddles after the
block is decked if necessary and all cylinders
are centered and bored,or sleeved and bored perpendicular to the Crank. And
as Harold says
it isn't possible with horizontally opposed engines(air or water cooled) to
recover the material through decking
and shaving the saddles without going oversize on the O.D. of the Bearing
surface. If a deck height is reduced
as a by-product of these procedures, the pistons have to be machined to
bring them back within the confines
of the block or else they would protrude above the block. Judging by
Harold's email address name he owns an
american made Formula Ford racer and has paid for some of these jobs done to
his English Ford Kent 1600 engine.
Warping of old cast iron Blocks isn't unusual, most times wouldn't matter
much if it's just splitting hairs, but most times
all these procedures are done to improve upon the old production machining
tolerances. It does eliminate parasetic friction that robs power.
Wayne Lee
Douglas,MA
58 TR3A
74 Hawke DL12 Formula Ford
Lola T-598 Sports 2000
----- Original Message -----
From: <ZinkZ10C@aol.com>
To: <tswrace@pacbell.net>; <mmarr@notwires.com>
Cc: <dconnitt@fuse.net>; <triumphs@autox.team.net>
Sent: Monday, May 30, 2005 9:58 AM
Subject: Re: Align bore.
> In a message dated 5/30/05 9:43:24 AM Eastern Daylight Time,
> tswrace@pacbell.net writes:
>
> << To align bore an engine as I understand it the machinist shaves the
> boss
> on the main cap. Then the caps are bolted in place and the mains are
> align bored. This results in mains that take standard bearings.
> >>
>
> To clarify further. Align bore ( AKA Align Hone ) mains is done to ensure
> all bearing saddles are centered so the crank does not rub.
>
> The main caps are cut down a bit it make the bearing saddle smaller, a
> long
> hone bar is then inserted through the main caps and the saddle hole
> brought
> back to size.
>
> For most engines, standard and undersize refers to the inside diameter of
> the
> bearing. ( the side that contacts the crank shaft) but there are
> exceptions.
> Some engines like air cooled VW or Porsche have a crankcase that splits in
> two halves rather than main caps. For these motors the saddle hole must
> be
> increased during line hone and a larger _outside_ diameter bearing used.
> If the
> crank has been reground a smaller _inside_ diameter bearing must be used.
>
> Harold
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