New pistons

JoelNelson · Aug 12, 2012

Hi everybody, I'm new here, but I have creeped this site for years. I'm in the middle of a top end rebuild and wanted some input as to which pistons people are using. I am leaning towards emgo(jcc) pistons with hastings rings, as I am on a budget. Has any one had a good/bad experience with these pistons?
Thanks
Joel

DogT · Aug 12, 2012

Check out Norvil or RGM, even with postage, you may do better. Seems like I used the Italian ones from Norvil.

Dave
69S

Whitworth Ranch · Aug 12, 2012

It's not Norton experience, but I was very happy with the JCC pistons (they make a lot of Japanse OEM stuff for new-bike production) I used in my pre-unit Triumph 650 top-end rebuild.

I can't speak to Hastings rings. Back when I did the Triumph engine, I just used the rings that came with the JCC pistons. Seemed fine, but they had iron, one-piece oil-control rings and I don't think I'd use those any more. These days, I have become a sealing/oil-control snob after using Total Seal on two cars and a bike engine, all with really fine results. But those were all custom pistons from JE when JE was still JE, which it is not any longer.

debby · Aug 12, 2012

I've been running EMGO pistons with Hastings rings in my 850 and the bike runs great. I'll definitely use them again in the future. I'm not a big fan of the one-piece oil rings that GPM uses.

Not sure if EMGO and JCC are actually the same pistons in different packages, or not. I have some JCC pistons for a 750 motor that I'm building and it appears the circlip grooves are cut too deep. Trying to get that sorted now.

comnoz · Aug 12, 2012

The JCC pistons and the Emgo pistons are the same. They are higher quality pistons than the GPM. I use them regularly. Jim

worntorn · Aug 12, 2012

About 15 years ago the local Vincent guys were all using GPM pistons. After a number of seizures it was discovered that these pistons were not cam ground at the factory.
They had been installed with adequate clearance for cam round pistons, but actually required about 50% more clearance due to the expansion problem. So they could have been used with big clearances, but this is going back to the old ways of high oil consumption plus some extra compression/power loss.
Surely by now GPM is cam grinding pistons, although it would be good to verify before using.

Glen

grandpaul · Aug 13, 2012

Welcome, Joel. Looks like a nice vintage race bike in your avatar; do you race at all?

I use Emgo pistons about 70% of the time. I explain my experience to clients, and let them make the choice.

JoelNelson · Aug 13, 2012

Yes I race that bike in VRRA period 1 open. I bought the Emgo pistons they seem like they'll be adequate for my street machine, plus I'm on a budget.

Matt Spencer · Aug 13, 2012

If youre on a Budget ,

Universal Motorcycles used " 1500 Cortina " pistons , in their 920 cc / 850 Speedway outfit .
For two Championship seasons , without a Blow up . Though they stuck to 32 mm carbs , and a sane redline . 7000 ish

BA10BOON · Aug 15, 2012

The JCC pistons are very good. As Whitworth Ranch states, they make a lot of OEM Pistons for new bike production, such as Honda's.
Personally, i've always had problems with the Italian GPM rings, rather than the Pistons themselves, especially on my 750's.
I have fitted JCC Pistons and Hastings rings on my two 850's this year, and both bikes run great.

kevbo82 · Aug 15, 2012

sorry to hijack things a bit, the guy working on my motor suggested hepolites as "the piston for the job" from what i understand they're O.E. pistons, are they indeed the piston for the job?

L.A.B. · Aug 15, 2012

kevbo82 said:
sorry to hijack things a bit, the guy working on my motor suggested hepolites as "the piston for the job" from what i understand they're O.E. pistons, are they indeed the piston for the job?

40 years on, Hepolite pistons are no longer made by the Hepolite company (and probably haven't been for the past 30 years or so) "Hepolite" pistons are currently produced by JCC in Taiwan/China so cannot really be considered "OE" any more than any other brand of piston unless those Hepolite pistons are old stock and supplies of those are mostly gone.

kevbo82 · Aug 15, 2012

L.A.B. said:
40 years on, Hepolite pistons are no longer made by the Hepolite company (and probably haven't been for the past 30 years or so) "Hepolite" pistons are currently produced by JCC in Taiwan/China so cannot really be considered "OE" any more than any other brand of piston unless those Hepolite pistons are old stock and supplies of those are mostly gone.

this guys shop was started by his uncle in the late 60's, and they've been saving every piece of norton's, triumph's, and bsa's since then so i wouldn't be surprised if they were NOS. I'll certainly ask out of curiosity. Thanks for the info.

ML · Aug 15, 2012

L.A.B. said:
40 years on, Hepolite pistons are no longer made by the Hepolite company (and probably haven't been for the past 30 years or so) "Hepolite" pistons are currently produced by JCC in Taiwan/China so cannot really be considered "OE" any more than any other brand of piston unless those Hepolite pistons are old stock and supplies of those are mostly gone.

Dunno about Hepolite being made by JCC in the Orient...last 850 pair I purchased from RGM a year ago was made by Federal Mogul, where the quality can be depended on (although I have no knowledge of JCC in any respect).

rx7171 · Aug 15, 2012

The JCC pistons that came in the EMGO box appear well made and they came with rings, pins.
No complaints on how they perform ove ther last 5,000+ miles.
Oil consumption so low it hardly registers.

L.A.B. · Aug 16, 2012

ML said:
L.A.B. said:

40 years on, Hepolite pistons are no longer made by the Hepolite company (and probably haven't been for the past 30 years or so) "Hepolite" pistons are currently produced by JCC in Taiwan/China so cannot really be considered "OE" any more than any other brand of piston unless those Hepolite pistons are old stock and supplies of those are mostly gone.

Click to expand...

Dunno about Hepolite being made by JCC in the Orient...last 850 pair I purchased from RGM a year ago was made by Federal Mogul, where the quality can be depended on (although I have no knowledge of JCC in any respect).

Yes, but Federal Mogul sold the 'Hepolite' brand name to Wassell about a year ago.

http://www.totalbikebits.com/wassell_history.html

In 2011, the Company acquired the Hepolite brand, trademark and goodwill from the Federal Mogul Group. Originally Hepolite was a brand name of Hepworth & Grandage, who later merged with Wellworthy Pistons Ltd, to form A E Piston Products Ltd.

New pistons

JoelNelson

DogT

Whitworth Ranch

debby

comnoz

worntorn

grandpaul

JoelNelson

Matt Spencer

BA10BOON

kevbo82

L.A.B.

Moderator

kevbo82

ML

rx7171

L.A.B.

Moderator

Similar threads