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upside down piston

Posted: Fri Feb 12, 2010 12:20 pm
by billyboy
`i removed this piston from a W century parts motor and found it mounted upside down.should i simply remove the gudgeon pin and invert the piston or do i need to undo the bearing and invert rod and piston? in other words is there a " right way up" for a century rod or will either way do? would appreciate any help. cheers http://i799.photobucket.com/albums/yy27 ... ge0037.jpg

Re: upside down piston

Posted: Fri Feb 12, 2010 12:36 pm
by chris
you can't mount a piston upside down, it can only go on one way, tassie is a good spot, lived in hobart for 10 years, bought my first seagull there in 1974

Re: upside down piston

Posted: Fri Feb 12, 2010 5:15 pm
by Keith.P
I found the same on a Anzani not long ago, just pull the pin and turn it, less trouble than playing with the big end.

Re: upside down piston

Posted: Fri Feb 12, 2010 11:53 pm
by billyboy
`thanks . i was rather hoping that would be the case. i got a bit worried when i read that the rods in the 40's had to go with "'SEAGULL'" up.
i would be interested to know though if the anzani had the cylinder ,rings , etc in almost perfect condition as mine were.like somebody had fitted new piston and rings and never got it started maybe.

Re: upside down piston

Posted: Sat Feb 13, 2010 1:57 am
by Keith.P
The Anzani was the 5hp, an E-bay job, would not turn over, it has head studs not bolts, the reason it did not turn over was that the piston was upside down, but this had been done some years ago and left as is, until I picked it up, ended up it had no compression anyway, so it only goo for parts.
Maybe your one was a unfinished restoration.

Re: upside down piston

Posted: Sat Feb 13, 2010 2:10 am
by billyboy
interesting. the century still turned over ok even with the deflector the wrong way up. there was a bit of "sticking" but i think that was in the crankcase which i hope is now fixed

Re: upside down piston

Posted: Sat Feb 13, 2010 3:22 am
by Rob Ripley
Depends on which end of the hemisphere you live in .... anyway I think it makes a nice decoration on the table.

Re: upside down piston

Posted: Sun Feb 14, 2010 12:04 am
by chris
I will not reply again whilst a self inflicted hangover is ruling my brain,
Have rebuilt a couple of seagulls and forgot about having piston around right way,
Might change the make of beer, it was becks, stella and guinness
any suggestions