New VB piston

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klaus gerhard
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New VB piston

Postby klaus gerhard » Thu Aug 29, 2019 3:21 pm

My 1953 VB suffered from an exploded piston. Part of the piston skirt broke off and went away into the depth of the crankcase. The engine kept running, although rattling a bit.
Now I received a new piston made individually for me. It had to be made to special order because non of the usual sources could help with a new Ariel piston.
Hope the bike will be on the road soon.
Regards Klaus
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1953_VB Kolben alt neu.jpg

Knud.Degnbol
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Re: New VB piston

Postby Knud.Degnbol » Thu Aug 29, 2019 10:17 pm

Hi Klaus.
What is the content of the can in the middle? ;)

nevhunter
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Re: New VB piston

Postby nevhunter » Fri Aug 30, 2019 12:33 am

The skirt on the new one appears to be longer below the gudgeon pin than the original one. Check it doesn't foul anything. Nev

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Steven.Carter
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Re: New VB piston

Postby Steven.Carter » Fri Aug 30, 2019 6:46 am

Knud.Degnbol wrote:Hi Klaus.
What is the content of the can in the middle? ;)

Head gasket sealant? Cera means head doesn't it! :D

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Steven.Carter
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Re: New VB piston

Postby Steven.Carter » Fri Aug 30, 2019 6:48 am

klaus gerhard wrote:My 1953 VB suffered from an exploded piston. Part of the piston skirt broke off and went away into the depth of the crankcase. The engine kept running, although rattling a bit.
Now I received a new piston made individually for me. It had to be made to special order because non of the usual sources could help with a new Ariel piston.
Hope the bike will be on the road soon.
Regards Klaus


It still ran?? Wow

john.whiting
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Re: New VB piston

Postby john.whiting » Fri Aug 30, 2019 7:46 am

A lot of modern bikes ,all there is of the piston is rings ,and a pin jammed up underneath.........just like yours if all the skirt was taken off.I dont know how they work...but they do.Looking at the deckheight ,a car piston would probably be found to fit.

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Re: New VB piston

Postby Gui.dorey » Fri Aug 30, 2019 10:47 am

Steven.Carter wrote:
It still ran?? Wow


Oh they run. Sometimes it is amazing how. This year my 1930 BSA Sloper just had a complete brake down - it just died in the middle of a tour and wouldn’t start anymore. When I measured compression later the gauge showed 0! I thought the gauge was broken.

When I opened the engine I found what you see in the pics. The rings had soldered themselves in the grooves too. The cause was lack of oil. The BSA sloper has manual oil flow regulator, just like a small tap one can open up more or less according to your needs. There isn’t a glass or anything where one can actually see how much is flowing. Idiot me just kept shutting it down to avoid her smoking like a steam engine - didn’t want to bother the neighbours and all that... I don’t know how many miles she ran like that, but a lot anyway, at least a whole season of rides and going to meets. Never did she really complain or showed any signs of heating up or something, the good old girl. She accelerated well and had power - the only thing was she never reached top speed, but who rides a 90 year old motorcycle above 100km/h anyway?

Now I’m waiting for a bore from the machinist and then will have a new piston made like Klaus here.
1A114967-901A-490E-8CF5-0E1097A66464.jpeg
FB9102B8-AA72-4F20-BA14-E1D3F47753BA.jpeg

klaus gerhard
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Re: New VB piston

Postby klaus gerhard » Sat Aug 31, 2019 4:35 pm

Hi Knud,
its a normal container that originally had a kind of hand cream in it. I reused it putting normal grease in it. It was just the right height for taking the photograph.
Klaus

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Re: New VB piston

Postby bevanclark » Sat Aug 31, 2019 9:23 pm

Gidday Gui, I am surprised that you are getting the rebore before the piston - isn't it usual to bore the cylinder to get the correct fit for the piston ?
Cheers, Bevan
p.s. real shame you haven't been able to identify an existing replacement piston. I've turned the oil control valve up on my Sloper after your experience, she's smoking quite a bit, but who cares !!

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brenton.roy
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Re: New VB piston

Postby brenton.roy » Sun Sep 01, 2019 12:29 am

They do make them here in Adelaide https://www.norndaautomotive.com.au/jp-pistons.html I think Ariel and BSA.
'51,'56 Squares, '48 VH, '27 Model C, R67/2, Mk IV Le Mans, '06 Super Duke and Ariel projects.


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