In a recent post, yours truly asked of the Scions of both Triumph and
Vintage-Race:
> OK, fellow Stanpart Scions, especially you who revel in the hallowed
> traditions of Triumph motorsport, this one has me stumped....Does anyone
> have any good ideas as to 1. where the middle [piston] ring [for a race-
> prepped 1964 Spitfire 4] went or 2. why it would not have been used when
> the engine was last assembled (long before we got the car)? I've never
> claimed to know EVERYTHING about Triumphs, but...
And:
> The piston/rod assembly I pulled last night also has some sort of white
> nylon(?) "buttons" inserted as caps on each side. Another racing trick?
> What for?
Thanks to the following -- Arthur K, Scott W. Paisley, Richard Jackson, Clark
Nicholls, Chad Jester, Michael Burdick, Chris Kantarjiev, Clay Scott, Eric
Thorstenson, Jim Hayes and Roger Garnett -- all of whom came up with all or
part of the answers, or at least darn good, logical WAGs. As I noted last
week, general consensus seems to be that the "Ring" thing is/was a trick used
to lessen friction and improve power in racing applications. And the
"buttons" are teflon, designed primarily to reduce the risk of cylinder wall
damage from a floating piston pin that goes astray. Arthur told me the story
of a mechanic who did this for his TR4, said mechanic being none other than
Spitfire racing great Rick Cline!
I'm currently debating (mostly with myself thus far) as to whether it's worth
going the missing ring way again for all that extra power. It might pay off
for autocross work, but I hate to think we'd have to go through this whole
minor rebuild thing again in another 10-12 years. ;-)
P.S. All four pistons were done the same way, so it wasn't a DPO bodge!
Andy Mace
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