Andy:
I am pretty sure that pistons 1-5 are original equipment
because they are numbered 1-5 in the proper place. It
looks like #6 is a standard size replacement, maybe due
to a dropped valve or something. It appears to be a very
low mileage engine judging from the almost non existent
ridge around the top of the cylinders. I was thinking
that somebody had done a funky repair, but now I think
that I may get away with just replacing the rings instead
of having to rebore and replace the pistons. Maybe the
R and S indicate the manufacturer who supplied the
pistons?
Dave
>Can somebody help me identify these pistons? I removed the
>head from my recently acquired GT6 project car and found, as
>expected, that it had a blown head gasket. When I scraped
>the crud off the tops of the pistons, I found that 1-5 have
>Stanpart number 214947 S31 on them. Number 6
>has 207045 R17. That was also the cylinder that had the
>blown gasket so this is apparently not the first time this
>has happened. Can somebody tell me how far #6 has been
>overbored from that part number? The engine is an early
>GT6+ block (KD53420E). Looks like it's time for some
>serious machine work and new pistons.
I'd first replied to Dave that: "TRF came up with one match [out of two].
According to [their online catalog], 207045 is a "Piston, Bare" and is no
longer stocked. I'm not sure what a bare piston is, except that perhaps it was
supplied without rings? Still leaves me wondering about the other five pistons,
though...."
But then I remembered that I had an early GT6 engine -- KC4213E -- with the
head off, all stuffed in the barn.Sure enough, I hit paydirt (well, actually I
scraped dirt off the tops of a couple pistons). This was a very low mileage
engine out of a wreck many, many years ago. But I digress. Pistons 1 & 6
carried the Stanpart logo and the number 207045. One had below it "R6" and the
other "R8" -- for whatever that's worth.
So perhaps the 214947 pistons in cylinders 1-5 are original "Pistons, Bare"
used in the factory assembly of that later engine, and the 207045 came out of a
dealer's stock to replace a problem piston in cylinder 6? What's confusing is
that part numbers in the factory Spare Parts Catalogues appear to be for a
"piston assembly" (p/n 139809 for early GT6 engines and 149976 for later
engines) that presumably includes rings and the wrist pin w/clips, whereas the
Stanpart number on the top of the piston is literally the (unlisted) part
number for just the cast piston itself.
Anyone got the head off an original GT6+ or Mk2 engine to possibly confirm that
214947 is an original piston for same?
--Andy Mace
*Mrs Irrelevant: Oh, is it a jet?
*Man: Well, no ... It's not so much of a jet, it's more your, er,
?Triumph Herald engine with wings.
? ?-- Cut-price Airlines Sketch, Monty Python's Flying Circus (22)
/// spitfires@autox.team.net mailing list
/// or try http://www.team.net/cgi-bin/majorcool
/// Archives at http://www.team.net/archive
|