Hepolite Pistons

Norton Dave · Jan 22, 2012

Hi all and G'day from Aust , there are some Hepolite Pistons for sale on Ebay , does any one think these are ok to run on a MK3 850 they seem very cheap , are these domed top pistons better than the flat tops any thoughts Norton Dave .

JimC · Jan 22, 2012

I bought some new Hepolite pistons off eBay a few years ago to replace the JRC pistons I was using. Unbeknownst to me, there are Hepolites with a large oil ring groove cutout. They will fail in a Commando 750. One let go in my Combat. In fact, they are referred to as flip tops. As for an 850, I don't know if any flip top Hepolites exist. All I can say is, all Hepolites are not suitable for a Commandos.

L.A.B. · Jan 22, 2012

The Hepolite brand name is now owned by Wassell.

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.

I believe these "new" Hepolite pistons are made by JCC.

beng · Jan 22, 2012

Someone recently showed me that the new Hepolites are not made in England any more, but somewhere in the East....

That does not mean their quality has to be bad though. If you watch ebay long enough something always pops up, it seems there are quite a few sets of NOS 850 pistons lying around, more so than for 750 or other Nortons.

Ron L · Jan 22, 2012

I have seen Hepolite boxes with the Federal Mogul tag on them that also carried a "Made in Italy" sticker. GPM? These were presumably made before the acquisition of the Hepolite name by Wassell.

L.A.B. · Jan 22, 2012

beng said:
Someone recently showed me that the new Hepolites are not made in England any more,

I doubt Hepolite pistons have been made in the UK for at least 20 years (not since they had "AE" on [Edit: black and yellow :wink: ] boxes!).

beng said:
but somewhere in the East....

JCC = http://www.jcc-parts.com/jqen/web/about.asp

beng said:
That does not mean their quality has to be bad though. If you watch ebay long enough something always pops up, it seems there are quite a few sets of NOS 850 pistons lying around, more so than for 750 or other Nortons.

However, buyers shouldn't be fooled by the new Wassel pistons which come in old-style Hepolite boxes that look as if they have been sitting on a dusty shelf for the past 40 years!

gripper · Jan 22, 2012

I've bought a pair of these hepolite pistons in the antique looking box off ebay. I had a good idea that they weren't original hepolite but at £106 inc p&p I thought they were worth a punt. They are for my planned rebore on my 70 fastback and to be honest they look good. The skirts have a very fine turned finish compared with a much smoother finish on an old slotted oil control ring AE item. That may just hold a film of oil where you need it.

L.A.B. · Jan 22, 2012

The pistons are OK apparently, but I remember kommando making a comment that the rings are not so good?

post58572.html

mikegray660 · Jan 22, 2012

L.A.B. said:
The pistons are OK apparently, but I remember kommando making a comment that the rings are not so good?

post58572.html

yes +1 on this - your better off fitting hasting rings or real hepolites if you can find them (good luck, like the hepolite pistons they are recent manufactured rings packaged in hepolite boxes etc etc - believed licensed by wassel too)

splatt · Jan 22, 2012

The compression ring are just a plain cast iron ring so just basic but do work, the 17mm circlips for 11/16 pins pissed me off more.

ZFD · Jan 22, 2012

"Real" Hepolites were quite all right in Commandos- we used them for decades, until AE phased them out and Andover Norton had them made by GPM due to Hepolite stopping production. Again, no problems with GPMs, neither race, nor road.
The "dangerous" Hepolites were for 750s, and the downward slots on these are joined by a horizontal slot each side that runs behind a piston ring (easy to see looking into the piston). these are fit only as ashtrays, but they haven't been made since the early 1970s. If you get them they are still there, new, because the experienced dealers and owners declined to buy and use them!

Real Hepolites have "AE" cast in their piston skirt.

Ron L · Jan 22, 2012

gripper · Jan 22, 2012

The envelope that the rings came in supplied with my hepolite (wassel) pistons has "printed in USA" That doesn't mean that's where the rings came from. I might fork out for some genuine american Total Seal rings. Any opinions on these?

JimC · Jan 22, 2012

Some three or four years ago, on this forum, someone posted that a certain Hepolite, the one with the large oil ring cut out, would lose their tops in a Commando. Now I see posts saying that Hepolites are O.K. for Commandos. What's the deal? I did have a Hepolite piston fail in my Combat. The piston top split in half and separated from the remainder of the piston. Made for one hell of a rattle.

L.A.B. · Jan 22, 2012

JimC said:
Some three or four years ago, on this forum, someone posted that a certain Hepolite, the one with the large oil ring cut out, would lose their tops in a Commando. Now I see posts saying that Hepolites are O.K. for Commandos. What's the deal?

Hepolites are generally OK, except for those early Commando pistons with the cutouts which ZFD described:

ZFD said:
The "dangerous" Hepolites were for 750s, and the downward slots on these are joined by a horizontal slot each side that runs behind a piston ring (easy to see looking into the piston). these are fit only as ashtrays, but they haven't been made since the early 1970s. If you get them they are still there, new, because the experienced dealers and owners declined to buy and use them!

http://www.norvilmotorcycle.co.uk/techtalk34.htm

JimC said:
I did have a Hepolite piston fail in my Combat. The piston top split in half and separated from the remainder of the piston. Made for one hell of a rattle.

Early Combats did have those weak pistons.

NOC Service notes:

PISTONS: Don’t buy new pistons with a slot under the oil control ring. This slot was deleted to avoid the top coming
off the piston when the revs were kept up towards 7,000. Of course, the slotted pistons are OK for the man who never
goes over 5,000 rpm. The later type are identified as Combat Pistons in the parts list, but the only difference is this slot - the
compression height of combat (non slotted) and standard (slotted) pistons is identical.

rx7171 · Jan 23, 2012

L.A.B. said:
The Hepolite brand name is now owned by Wassell.

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.

Click to expand...

I believe these "new" Hepolite pistons are made by JCC.

I got JCC pistons for my 750 in Emgo boxes.
Quality looked very good and came with rings, wrist pins, circlips.
Very happy with performance and so little oil consumption can't hardly measure it.

stockie2 · Jan 23, 2012

Gripper,

I have total seal, but these are in the second groove only, in US made short skirt pistons out of a Jim Schmidt rod & piston kit. The TS rings do make the pressure on kicking her over much firmer, you can show off to your mates, and stand on the kicker and it will support your body weight. They also seem to help cold starting, as they draw up fuel real good.

Cheers Richard

MattinTexas · Jan 24, 2012

My 2 cents worth
Here are some pictures of what ZFD posted. These are out of the 750 Commandos that I am restoring. these are both AE marked Hepolite pistons. The piston on the right in the photos is from my 68 750 that is for my Commando R replica. The piston on the left is out of my 71 750 Roadster. The piston on the right has the horizontal cutout that joins both slots. The 3 slot pistons are marked 160001 on the crown. The later 2 slot pistons have un-slotted ring groves and lack the 16000 number on the crown.

xbacksideslider · Jan 24, 2012

Back in '72, one day in Griffith Park, one of the OEM pistons as originally fitted in my first Commando, a '71 Roadster, came apart at about 7000 miles. Made an awful racket.

On tear down, reading the parts, the piston split into two pieces, crown and skirt, then the valves opened and sort of pushed that crown back down and then the lower half of the piston would push that crown back up into the chamber and then the valves would push it down again. Rings stayed in place, didn't hurt the bore or the chamber, just bent the valves and scuffed the squish area.

I was dissappointed with Norton when I saw those stupid oil slots. Why? other manufacturers used small chamfered holes.

Hobot · Jan 24, 2012

Comma oil slot piston let go was reason for Trixie Combat '07 2nd rebuild, but was aggravated by also being rubbed on by Al gasket stuck in before me time, which was only 3 wks after 1st rebuild d/t deer strike doing everything else but engine and tranny which were fine the 1st 3 wks before dam deer. If any Al alloy part in a Commando has a life time heat cycle and flex limit its these obsolete pistons. I not longer consider it an economy of effort not to pop the top off an otherwise unknown fine running Norton. ugh.

Hepolite Pistons

Norton Dave

JimC

L.A.B.

Moderator

beng

Ron L

L.A.B.

Moderator

gripper

L.A.B.

Moderator

mikegray660

splatt

ZFD

Ron L

gripper

JimC

L.A.B.

Moderator

rx7171

stockie2

MattinTexas

xbacksideslider

Hobot

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