As some of you know, I have decided to completely rebuild the 1275 that is
sitting in my '67 Sprite MKIV (Vicky). I took the engine to a Racing Engine
shop that does machine work to have the engine checked out and just got the
engine and the verdict back. Scary thing is the engine is now in pieces and I
didn't have the advantage of taking it apart, so putting it back together
again will be a lucky combination of prayer and Haynes (the manual, not the
underwear, although in some ways I will be flying by the seat of my undies).
LOL
Anyway--Several questions to those of you who know much more than me about
these things:
1. The engine crank, rod bearing bores, Maiin bearing bores,and everything
else, bearing-wise checked out ok. The bearing weren't even bad although I
will be replacing them since I am there. Two biggie problems: The cylinder
has previously been bored and oversized pistons have been fitted. The bore
checks out at 2.809. This exceeds the top limit indicated in the shop manual
for the largest oversize piston. The machinist recommended that I would need
to bore, sleeve, and re bore the cylinder to fit the existing pistons to
regain engine health.
2. He also said the bolts were loose in the rods--I think when they are
loosened that they fit into the holes loosley. Is this normal? Of course
when they are torqued they are tight and do not move. Are they OK as long as
I can get them to the recommended torque and they are tight in the rods at
that torque (And locktabs set, of course)?
3. We have discussed hot-tanking the block. Everything I have read indicates
that the cam bearings MUST be replaced after hot tanking. I read somewhere
else that this required special equipment--even a special reamer to ream out
the old bearings. What to do here? Is this something the machinist is
expected to do, or can I do this myself (in my noviced condition).
4. Some discussion of plastiguage has been passed along on e-mail and on this
network. Could somebody tell me about that? Here is what I dont understand
about plastiguage: I just had my engine micrometered by a machinst--He said I
neede the REGULAR sized bearings. OK! So is the plastiguage a plastic
material that I would squeeze onto the bearing surfaces of the OLD bearings,
retorqueing everything, that dries and upon checking the thickness is a check
on the machinists findings? Or is the plastiguage used on the NEW bearings?
This seems redundant because once the new bearings are bought to fit
(according to a machinist with a micrometer) what is the point of squirting a
plastic material in to prove that you just wasted your money?
I will be progressing slowly as I read your responses. I will appreciate any
and all input. Also any tips, ideas, logic, philosophy, jokes, horror stories
are welcome. Thanks guys.
----David Campbell
|