Author Topic: SOURCES OF NEW PISTONS FOR POST WAR MODELS  (Read 4656 times)

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Offline Brian

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SOURCES OF NEW PISTONS FOR POST WAR MODELS
« on: 26 Mar 2006 at 18:35 »
Can any members please give their vieews on the sources and quality of pistons for
post-war Mark and Plus models.i have had widely conflicting advice on JP ;Peter Hepworth; Honda etc Most new old stock original Hepolites seem to be extinct except in STd size. I look forwward to the comments of the cognicenti.I have a 1951 80 Plus.
Thanks
Brian Thorby  Scotland

Offline aggettd

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Re: SOURCES OF NEW PISTONS FOR POST WAR MODELS
« Reply #1 on: 27 Mar 2006 at 14:52 »
Cognescenti I am not. But I have heard the Suzuki GS650 pistons are better than the Honda CB750 pistons, if only because you lose less compression (the distance between the wrist pin and the piston crown is slightly greater, more closely resembling the domed Douglas original.

David Aggett

Offline Ian

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Re: SOURCES OF NEW PISTONS FOR POST WAR MODELS
« Reply #2 on: 27 Mar 2006 at 20:06 »
While I have no experience with post-war Douglas I and friends have used JP pistons in many vintage cars and bikes including Douglas. My experience with bikes using their pistons is that if you totally ignore their recommended clearances then they are great - I had great problems when I intially started using them on motorcycle engine rebuilds as the suggested clearances were too small. The only other thing we have found is that the circlips they supply with some pistons are very suspect - a friend just got some pistons for a 2.75 HP Douglas and had a circlip fall out - the metal was very soft.