Seagull

[Graham Williams 5Participant @grahamwilliams5]

Just made the pistons for this engine (in cast iron as no Alum available) and have drilled and reamed the gudgeon pin holes to nominal 3/16″ as per drg. Con rods also show little end as 3/16″ dia and rod is shown as having what I presume is an oil hole drilled to lube the pin. Now what I’m unsure of is this :- should the pin (case hardened MS) rotate in the piston when running and perhaps in the con rod or should the pin be fitted tightly to the piston (perhaps by warming the piston ) as in my old M/bikes? or does it matter at all. Advice appreciated.

[Graham Williams 5Participant @grahamwilliams5]

Gudgeon Pin fit

[Sub MandrelParticipant @submandrel]

Push fit in piston, rotate in con-rod. – stops it moving sideways as I understand it

 

Neil

[Graham Williams 5Participant @grahamwilliams5]

Thanks for the replies, had a look at Graham Meek’s page was most interesting. As the drg shows end pads I’m going to make the pin fully floating as Graham’s.

 

Cheers

Graham W

[Graham Williams 5Participant @grahamwilliams5]

Hi Robin.

 

Errr no didn’t clock that they were hollow dowels, what advantage would that give ? lightness I suppose. What I did see tho’ was the pistons which must be a whole lot lighter than the ones I’ve made so we’ll see what mine revs out to and perhaps vibrates like when all finished.

Cheers

Graham W

[Author]

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