Forum

[adamscarborough]

Hardly broke Beezabryan, If I had a hole in the top of my piston it would be but I haven't

[Bullet Whisperer]

Shims under the rocker blocks will not help. The inlet valve is too big and too close to the piston when it is seated, never mind when it starts to open.

[Dennis C]

Am I missing something here?, Or is the short answer to fit the correct size valve?, The oversize does nothing for the performance anyway.

[Mark M]

Paul, I agree with you but Adam is trying to eliminate possibilities and this is a way of doing that. If I was him and maybe feeling a bit baffled by the problem I'd probably do the same thing. Occasionally even now I approach new problems in this way and build my knowledge as I eliminate possibilities and make progress towards a clearer understanding of what's going on.

REgards, Mark

[Revband]

If you raise the rocker block you then need to extend the pushrod adjustment to match and the valve will still open just the same I think.

[adamscarborough]

Thank you for your help. I've got some things to try and some solutions to investigate. Unfortunately I'm on holiday next week so I might fall silent for a while.
I'd like to point out that Hitchcock's have sold hundreds of these valve kits without customers having issues, many people are interested in finding solutions that will benefit everyone. Importantly it might be that my issue has highlighted that other people’s valves could be very close to their piston, but they are unaware of the fact, and improvements could be made to a popular modification.
It may be that the modification is un-necessary in some people’s minds but there are people who own Enfield for reasons other than to see highly polished they can get their engine casings, they see ownership as a hobby. The hobby of tinkering with their bike for no other reason than to tinker. I'm sure that the likes of Burt Munro didn't think, I'm not going to touch that because it's not how it was originally designed and it probably doesn't make much difference anyway.
Adam

[stinkwheel]

They have sold many of the kits but I wonder how many people have fitted a big inlet valve and alloy barrel but retained a standard piston? I'd suggest very few.

[adamscarborough]

Which piston do you recommend? I'm currently thinking the Omega forged 84mm 6.5:1

[Bullet Whisperer]

If your inlet valve, which is too big and too close to the standard piston is going to stay, I doubt it will clear any of the higher compression pistons available. That inlet valve looks bigger than what I have in the 500 racer, which produces over 46 bhp @ rear wheel and can win races. I am not Burt Monroe, though, so who am I to tell you what should work and what shouldn't. I bow to your superior knowledge.

[Revband]

Well you ask for help on something which I am sure some people who have tried to advise you about and obviously have far more experience on the subject than you do Adam? and you treat them to a reply like that, good luck with it you don't deserve to be helped.