New pistons

Got to buy oversize pistons, have made contact to Roger at RGM and asked what pistons he has in stock, he told me he stocks GPM (Italian) new Hepolites and has old Hepolites in stock but he said he has sold a lot of the new Hepolites and have not heard anything bad about them, what is everone else thorughts on new Commando pistons, will be ordering them next week.

Ashley

Shoot if RGM ain't getting complaints then go for the lightest set. Over size bores up the CR a bit beside up the stroke volume. Ideally wait for pistons in hand before dealing with bore to fit.

The cylinders will be bored to the new pistons and final hone, so all good there Steve.

Ashley

I have the an old set of .020 over in mine that I got from Mr. Kline at GT Motors in Lansing. A dealer that closed down in the mid 80. I called him a few years back and met him out front. He unlocked the door of the dilapidated building and come out with a pristine set. I am sure some of the Michiganders know who Im talking about.
I like the old ones if you can get them. They are what they are, Hepolite's.

If it was my bike I would put the old Hepolite's in it as you can run them with tight tolorances, but this will be up to the owner, this bike won't get much running in a year as my friend is a seaman and spend half the year at sea and he has a few bikes in his collection, but then if he gets bitten by the Norton he mite just keep ridding it, which ever way I will build this bike to be very reliable and strong, being a Triumph man he might not be able to kick it :lol:

Ashley

ashman said:

being a Triumph man he might not be able to kick it :lol:

Ashley

Click to expand...

I have a sure solution for that........... http://norcomcycles.com/Norton_eKit.html

The best part about owning a Norton and thats learning how to kick it right, after 37 years of ownership to mine it just comes natrual to me.

Ashley

I just rebored my 850 to +20 and used the new Hepolites (JCC ) but I used new old stock genuine Hepolite rings as I'd had bad experience with the supplied rings when I rebored my T140 a couple of years ago .When I fitted genuine rings it was sorted out.
The JCC pistons are very well made, and the Commando is running beautifully on this set up.

sam

I'm running the new Hepolites in my Combat with no problems at all - the supplied rings (Hastings, US) work fine, but the oil ring separator (3-piece oil rings) needed gapping even though the rings didn't!

I'm more than happy with them and won't hesitate to use them in future builds.

What was wrong with the T140 rings, Sam?

Hi Andy,

In a word "smoke"
Had the barrel bored to the pistons by Bill Bannister in Bamber Bridge, great engineer !
Put it all together and it smoked like a trooper, so contacted Rockerbox where I'd bought the pistons, they told me they had heard of problems before, and gave me the number for LF Harris production boss John Birch , anyway, long story short , he sent me some NOS Hepolite rings to use with the pistons, built it all up again and no smoke and running great.
That's why I sourced some NOS Hepolite rings when I done the Commando just a few weeks ago.
Must say with the supplied rings from Rockerbox/L F Harris, there was no indication on the rings or the packets which was the top and 2nd rings or which was top side on either . There was also no taper that I could see anyway.
I note now that LP Williams the big triple dealer is offering rings made by Omega to use with the JCC pistons, as a lot of buyers were dissatisfied with the ones supplied.
I have a good friend in the USA Charlie Barnes top triple guy as well as others here who will not use Hastings rings whatsoever.
As usual though, if yours is working well , just leave it alone.
PS
If you are up to any Commando painting yet please contact me on trident.sams@gmail.com

cheers
sam

Sam if the pistons you fitted to your T140 were JCC from two years back they could have been supplied with Taiwanese ring sets
which were not good , the new production Heploite pistons now have Hastings rings which replaced the Taiwanese rings
if the JCC pistons were supplied by LF Harris then not sure what rings are fitted

personally I have Never had any issues with the new Hepolite/ Hastings Commando / T140 rings
but Hastings T150 / T160 do have issues ( but then again they did from new anyway ) that's why AE developed the three piece oil for the triples