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By Alan R
#27306
Hi guys---------- yes, that was yours wasn't it MIDGE ?? ---- Glad to hear the bikes' going well..BEEZABRYAN, it's interesting to see then that this year our hosts have introduced a forged piston at STD Comp. ratio------------- I wonder why, eh ???
By carpe diem
#27599
Hi Midge
this must be a pic of the damage you were talking about.
Nice meeting you today, hope you get on ok with the seat:-)
By Alan R
#27603
Hi guys----------- just for interest sake, attention the "Non-Engineering" owners reading this.......Have another look at the piston photo..Notice the two vertical slits and how you can just see the top of the con rod ?? Well that battered horizontal surface ( and its' mate on the other side )is all that joins the crown to the main body, and is the total area of Aluminium that stops the crown's continuing movement at top and bottom dead centres ( at anything up to 5,000 times a minute as well).......it's made from CAST ALUMINIUM.....
By Norm
#27609
Hi Alan, we have one going on out here at the moment, piston lost its top, the owner pulled the motor down, cleaned everything out, fitted new piston but a couple of thousand ks down the road the bottom end has given up. Once those piston bits go through the bearings they have to be replaced, you are only creating more work for yourself if you don't
By Alan R
#27611
---------that's right NORM, it's a FULL strip down to be absolutely sure, isn't it ??.......All the more reason to get it right whilst you can, I would say...Earlier you saw Mr H's FORGED 8.5 : 1 piston being fitted last year on my No1 Bullet, whilst the Army No2 will be getting their new FORGED std. CR one Spring next year....(Hopefully both will be getting a steel con rod as well)........
By Alan R
#27622
Hi guys---------- what you can't see is the 3mm (de?)compession plate fitted as well--------Estimated 7:1 CR for tractability....With the 28mm carb suitably jetted it ran very well indeed..

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