[Fot] Piston to Wall clearance Now Vincent Black Shadow

[Bill Babcock]

I mis-spoke. I picked my Vincent up today from the guy who rebuilt it,  
and discovered he replaced the rings. the plan was to re-use them, but  
he decided against it. He re-used the pistons, but ditched the rings.  
It's been at other people's shops for way too long. I'm looking  
forward to finishing up the little nits that still need to be  
corrected and doing some riding on it. It's a great bike.

There's some shots on Peyote's and Nero's site: http://www.allaluminumtour.com/

On Oct 31, 2008, at 11:42 AM, Bill Babcock wrote:
>
> My old (1950) Vincent Black Shadow has uncounted miles on the  
> pistons and rings, mostly with a pretty marginal air cleaner. It got  
> a complete teardown recently because the bottom end was noisy. But  
> other than refurbing guides, grinding valves and replacing the  
> bottom end bearings, pretty much everything went back in for another  
> 58 year round. The rings were worn a little, especially near the  
> gap, but they were sealing perfectly and had perfect tension. No  
> sign of blowby on the piston skirts, no overheating of the rings. I  
> could have replaced them for not much money, but chose not to. Not  
> because of the cost (trivial, compared to the labor--tearing down a  
> vincent is a MAJOR piece of work) but because they were working  
> well. In my experience you have more problems getting sliding parts  
> to bed properly than any wear issue. And while they are bedding, hot  
> gasses are blowing down the piston wall, overheating the rings and  
> annealing them.