wallaces@superaje.com wrote:
>
> I am torn between getting the sleeves from my 3a engine bored, or getting new
> ones - the dilemma is financial otherwise the decision would be simple.
> I am told that locally at least, it would be difficult to find someone to bore
> them because they are used to depending on entire blocks for stability when
> boring i.e. the cylinder must hold still to assure a good job, and the weight
> of the entire block helps. A set of new sleeves however becomes a mighty
>expensive
> proposition by the time they land on my doorstep here in Canada.
> So the question becomes: is it the experience of list members that there are
> indeed machine shops around (North America) who can cope with sleeves, and is
> it cost-effective to get them done?
Before you decide, Jim, take the sleeves to a local machine shop--have
them cleaned and inspected and miked. If the cylinder surfaces are good,
more or less within tolerance. If they are, have them cut the ridge out
of them and hone them, and simply re-ring the engine. If cost is a
concern, you can re-ring with cylinders worn as much 0.004" to 0.006" as
long as the wear is fairly uniform (no horrible taper or
out-of-roundness). The job just won't last quite as long as would a job
with the clearances within factory limits. I've done engines when money
was tight with as much as 0.009" oversize, and the engines still went
another 60-70,000 miles before the oil consumption became obvious.
Nevertheless, one of the hardest lessons for people on tight budgets to
learn is that spending money for necessary machine shop work is not
money thrown away.
> It is very easy to say "just get new ones". If it turns out that there really
> is a difference of say < $100 I will go with new sleeves, but, this is money
> that could be put toward new pistons, rings, main bearings, tappets, big end
> bearings, thrust washers, head gasket, small end bearings, camshaft bushings,
> valve guides, exhaust valves.....or who knows? There could even be something
> else to spend money on.
I think you will find that the difference would be quite a bit more than
$100 Canadian. Much more. Even if the cylinder bores were in bad shape,
boring them for the next oversize piston and buying a piston and ring
set would be much cheaper than a new sleeve and piston set, and possibly
cheaper than just new sleeves themselves of the original size.
Others may correct me, but boring the sleeves 0.010" oversize will
probably not affect the strength of the sleeves in any measurable way.
> Maybe I should have taken up quilting as a hobby.
You could, but you can't drive a quilt. <smile>
Cheers.
--
Michael D. Porter
Roswell, NM
[mailto: mporter@zianet.com]
`70 GT6+ (being refurbished, slowly)
`71 GT6 Mk. III (organ donor)
`72 GT6 Mk. III (daily driver)
`64 TR4 (awaiting intensive care)
`80 TR7 (3.8 liter Buick-powered)
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