Hi Gerard,
After reviewing your note, I would either have the machine shop give the
engine a good look over. You will need a good set of inside and outside
mic's to check for wear further. If there is a ridge at the top, I
would guess there is a lot of wear on the bottom end also. The cranks
shafts will wear oblique, out of round. Wear is real evident on the rod
journals. Even though they may look fine and polished wear can be
present. The cylinder walls show wear from top to bottom. Check the
pistons for wear on the skirt, there shouldn't be rub marks on the
pistons.
I'm not saying that the engine is shot. In fact, I found a block with
no wear on it to for puddles. I rehoned the liners, bought new pistons
and was ready to go. Later we found out that it was taken out of
service because the clutch was put in backwards. So it is posible to
find a block with no wear on it.
Good luck
Rick
Gerard Chateauvieux wrote:
>
> Spridgeteers,
>
> I am seeking the wisdom of those with engine rebuilding expertise.
>
> I have a 1275 that I examined today for redbuild potential. This was a
> running engine when removed, but I never witnessed it's performance. I'm
> under the impression this is not a high milage engine judging by the
> condition of the crank journals. The head needs a complete overhaul, but
> the bottom end seems to be in decent shape. The crank journals, both main
> and rod, seem to be very good shape without grooves or significant
> scratches and retains a polished looking surface. The bearing shells (all
> standard) are mostly intact with a bare minimum of copper core showing
> through, with only a sixteen to an eighth inch wide areas showing through.
> The wear on the main journal is on the front edge of the front and center
> and none on the rear. The rod bearing shells show a little wear right in
> the center where the oil passage is located.. The cylinder walls do have a
> very slight ridge at the top of each wall. After decarbonizing the pistons,
> numbers 3 and 4 seem perfect, but pistons 1 and 2 have an orange peel-like
> surface and what look like some minor dings on the left and right sides of
> the outer edges. I'm guessing that cylinders one and two were run a bit
> lean and perhaps were run too hot. Engine number is 12GG-DAH-12111. It has
> the thin flange.
>
> I also have a thick flange 1275 block that has been tanked and
> magna-fluxed. It has new cylinder liners, though I'm not sure if they're
> standard bore or not.
>
> My questions are:
>
> * Is it possible to polish the journals and install a new set of bearing
> shells? * Is this something that I can do myself or does this require a
> machine shop to accomplish? I remember someone saying it could be done with
> #600 paper.
>
> * Should the cylinders be professionally honed or bored, or can I get by
> with breaking the glaze with a hone, and installing a new set of rings?
>
> * Are the 1 and 2 pistons salvageable or is a new set in order?
>
> I would have the block hot tanked before doing anything.
>
> Any suggestions or recommendations? TIA.
>
> Gerard
>
> G G Gerard Chateauvieux
> E A
> R R pixelsmith@gerardsgarage.com
> A A
> R G Pixelsmith on Duty
> D E
> S http://www.gerardsgarage.com
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