Reboring
 

I've had rebores done before but never seen the process. Over to Allen Millyard and his 4 cylinder 550cc S1 two stroke...

https://www.youtube.com/watch?v=hp66Sx62Aj0

Re: Reboring
 

In awe of the guy

Re: Reboring
 

That was a good watch. We even learned how to make cupcakes!

Re: Reboring
 

Yes, great insight into the process.

I also like the concept of reuseable copper head gaskets that was part of this.

Now all I need to understand is how to make pistons and valves and I might get somewhere with really restoring my FZ engines! :scratch:

Re: Reboring
 

I used to make my own copper head gaskets for my T140V 750 Bonnie, to replace the crap composite head gaskets which used to blow between the cylinders.

Re: Reboring
 

Was it just a case of cutting sheet to the right shape and annealing? Did they seal ok at the bore edges?

(I keep reading about needing extra ridges, often loops of wire in grooves, to compress the copper around the bore tops.)

Re: Reboring
 

Yep, I just cut the sheet using a new composite gasket as a template and then annealed it. You could re- anneal and use four or five times before it got too out of shape, then it was time to make a new one. Had no problems with sealing.

Re: Reboring
 

If only Triumph twin pushrod tubes were as easy to seal ....

Re: Reboring
 

Good to know. Thanks!

I feel an experiment coming on in the (hopefully) not too distant future. I have an FZ600 engine (aircooled in-line 4) that needs a rebuild and I'd like to get it running for sometime in the summer.

Re: Reboring
 

I'd never thought about that but I can see how it would help. You could always make very thin copper washers to go around each bore, but they would not want to be any more than a few thou thick.