To suit my iron 1952 VH500.
Bore is +20 at present and a +30 rebore might be enough but would be happy with a +40.
Would be happy with anything that will fit as Single Spares have no stock and apparently will not "until middle of next year" And Drags also have none. So any usable s/h piston would be great.
Can't bear the thought of the Ariel sitting in the garage, maybe for 6 or 8 months, unridable for the sake of one part.
Wow! Suddenly I'm cheerful again.
I have emailed them and will take the cylinder to Hamlins in Bridgwater tomorrow and see what rebore size is needed.
Thanks !!!
I got a piston from Thornton's Its a JP which it wasn't named as that on their website.
Having trawled through the extensive threads on the subject I understand the excess weight and balance problems and the advice to have 6 thou instead of JP's recomended 4 thou clearance.
These I can live with, especially if I can get some reliable advice on lightening the piston.
But the biggest problem is, the gudgeon pin is too big ! I am really tee'd off with parts for old bikes being produced with little care over accurate fit.
Its not a huge difference in diameter of the pin, as confirmed by Hamlin's this mornig. But its just enough for the JP pin not to fit in the smallend bush or the original piston, and the Hepolite pin is too loose a fit in the JP puiston.
I might be able to ease the diameter of the small end bush, but if I later get a decent piston, I'll have to get a new bush fitted.
So I'm considering options.
As Draganfly now list VH500 pistons in stock, I enquired what type. JP was the answer and they don't have +30 which I have and cylinder is now bored for.
Allan at Single Spares has some on order but "not until the middle of next year" I am hoping these will be the Omega 7.5:1 which seems to have been favourite in the threads I looked at.
But what to do until then ? I don't want half a year to go by without riding the Ariel.
So repeating the ask. If anybody has a usable piston, low or medium compression, +30 ideally with correct size gudgeon pin I would be so very grateful.
I've only got a spare +20 and it's dished.
It's a heplex, but there is no pin.
I had a JP piston in another 500 I had. I didn't notice any additional vibration. I did bore a little more clearance and I did have to take a little off the small end bush.
John Nash
AOMCC No.4119
Modern 2005 bonneville, '78 t140 bonneville, '77 BMW R80, '67 CJ750, '59 super meteor, '47 VH twinport, '44 Ariel WNG, '42 indian 741b
