G3 Piston Orientation

Information relating to the Matchless G3 or AJS Model 16 350cc Heavyweight
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stevetemple
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G3 Piston Orientation

Post by stevetemple »

I am building a G3WO engine and I am not sure which way round the piston should be fitted. There is a slit cut in one side of the piston skirt, should that face the front of the bike or the back?
Steve.
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Duncan
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Re: G3 Piston Orientation

Post by Duncan »

I have just dug out a new standard 9990 piston that has FRONT stamped on the small round crown on the side with the slit. Heplex_Pistons_Fitting_Instructions in the Archives states the split should be facing the non-thrust side of the engine.
stevetemple
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Re: G3 Piston Orientation

Post by stevetemple »

Thanks for replying Duncan. It makes sense that the split would be on the non thrust side, but wouldn't that make it facing the rear of the bike?
stevetemple
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Re: G3 Piston Orientation

Post by stevetemple »

My mistake the thrust side would be the rear face, so the split would face the front.
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Duncan
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Re: G3 Piston Orientation

Post by Duncan »

To be honest I couldn't work that one out when I read it either
g80csp11
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Re: G3 Piston Orientation

Post by g80csp11 »

is it not like this , viewed from timing side ? , so slit to front of engine
piston orientation.jpg
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Duncan
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Re: G3 Piston Orientation

Post by Duncan »

Excellent Peter thanks, in my head I know split to the front, but I needed to find the evidence to advise.
g80csp11
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Re: G3 Piston Orientation

Post by g80csp11 »

easy when you know
stevetemple
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Re: G3 Piston Orientation

Post by stevetemple »

Thanks all!
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