I think you'd be flat out getting a good alloy barrel.. The Velocette 500's went back to iron as did the 500 twin ARIELS. Just having a good alloy head will reduce detonation but they need a complete redesign with a shallower combustion chamber and a bigger inlet than exhaust valve and properly flow...

Duck's disease refers to having your bum too close to the ground. Nev

Had some of those but I've got the ducks disease so thought I'd go the Bartram Ht5 way and it's 132 KGs. Thanks for the reply. Nev

Might have missed my chance for a run with a HT (Trials) unless someone has an unfinished Project. I have the forks wheels and mechanicals and Hagon AMC gearbox Need clutch and kicker mechanism. Nev

Maybe we should go the way Velocette did. Revert to the Cast iron barrel and steel push rod cover tubes for cooling and lightness and have the fifth stud for the 500's incorporated in a new pattern. If I was a bit younger I'd probably do it. The pattern is not that complicated. The Later 500cc twin ...

The set up of the Twins and SQ4 is different. Load carrying capacity of deep Groove high load ball bearings has improved. Corrosion and cage failure can happen with any. . For the amount We use this stuff a Ball bearing set up would be reliable and adequate. Till the extra bearing on the drive side ...

Thanks David. That's certainly a very creditable showing. Australia per head of population would rate pretty highly at the level of ARIEL sales back in the day. Nev

How HOT is it? Looks like A good turn up. Nev

It's also very important to get the small end boss central. Where's the Noise coming from? Do you see any evidence of something being where it shouldn't be? Nev

Duplicated and hopefully deleted this time Nev