Strange-looking piston

Information relating to the Matchless G2 or AJS Model 14 250cc Lightweight
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clanger9
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Strange-looking piston

Post by clanger9 »

This eBay auction appears to include the 10.5:1 high-compression piston from a CS engine (part number 042242 - discussed in this thread).
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What's with the holes in the skirt? I've not seen a piston like that before.
Is it to improve oiling? My 9.5:1 piston (part number 043646) just has a solid skirt.
1989 Moto Morini Dart 350
1993 Ducati 750SS
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Rob Harknett
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Re: Strange-looking piston

Post by Rob Harknett »

If this has ben done by some one trying to lighten the piston, it could go wrong. Pistons are oval and expand round when they warm up. The holes may prevent this from happening. I have seen a piston like that from the early 1900's Motor Cycle magazine I'll see if I can find it but not spend to much time looking.
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robcurrie
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Re: Strange-looking piston

Post by robcurrie »

Sometimes teflon buttons are fitted in skirts, is this provision for them?

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Janet
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Re: Strange-looking piston

Post by Janet »

robcurrie wrote:Sometimes teflon buttons are fitted in skirts, is this provision for them?

Rob C
Is that so they don't stick when you're unfastening them?
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robcurrie
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Re: Strange-looking piston

Post by robcurrie »

...so that sweaty fingers can't undo them ;)

Rob C
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