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350 barrel on a G2
Posted: Tue May 16, 2017 5:36 pm
by BultacoBen
I knew the 250CSR head fitted the 350 barrel, but did not know you could mount the 350 barrel to the 250 bottom as the bike in this ad claims:
http://www.carandclassic.co.uk/car/C832146
I thought the 350 difference was taller barrel (stroke 10mm longer, bore 3mm wider) so is this conversion not just likely to give very low compression?
Re: 350 barrel on a G2
Posted: Tue May 16, 2017 10:41 pm
by clanger9
Presumably it's got a 350 crank, rod & piston as well? Fitting just the barrel & head would make no sense...
Re: 350 barrel on a G2
Posted: Wed May 17, 2017 12:15 pm
by Ozmadman
clanger9 wrote:Presumably it's got a 350 crank, rod & piston as well? Fitting just the barrel & head would make no sense...
Yes, it would have hardly any compression if not. Plus it is well overpriced even with a grand off it would still be expensive!!
Re: 350 barrel on a G2
Posted: Wed May 17, 2017 5:13 pm
by ajscomboman
Ozmadman wrote:clanger9 wrote:Presumably it's got a 350 crank, rod & piston as well? Fitting just the barrel & head would make no sense...
Yes, it would have hardly any compression if not. Plus it is well overpriced even with a grand off it would still be expensive!!
It wouldn't have any compression at all, 250's have a 69mm piston 350's use a 72mm.
Re: 350 barrel on a G2
Posted: Wed May 17, 2017 6:37 pm
by Janet
ajscomboman wrote:Ozmadman wrote:clanger9 wrote:Presumably it's got a 350 crank, rod & piston as well? Fitting just the barrel & head would make no sense...
Yes, it would have hardly any compression if not. Plus it is well overpriced even with a grand off it would still be expensive!!
It wouldn't have any compression at all, 250's have a 69mm piston 350's use a 72mm.
On the bright side, it's unlikely ever to seize in the barrel.
Re: 350 barrel on a G2
Posted: Wed May 17, 2017 8:06 pm
by ajscomboman
[quote="Janet" On the bright side, it's unlikely ever to seize in the barrel.[/quote]
Re: 350 barrel on a G2
Posted: Wed May 17, 2017 10:25 pm
by Ozmadman
ajscomboman wrote:Ozmadman wrote:clanger9 wrote:Presumably it's got a 350 crank, rod & piston as well? Fitting just the barrel & head would make no sense...
Yes, it would have hardly any compression if not. Plus it is well overpriced even with a grand off it would still be expensive!!
It wouldn't have any compression at all, 250's have a 69mm piston 350's use a 72mm.
I was presuming that at least they put the 350 piston in!!!
Re: 350 barrel on a G2
Posted: Thu May 18, 2017 8:14 am
by ajscomboman
Relax Paul, I was having a laugh. They'd had to have put in a 350 piston, goes without saying really.
