Emgo pistons

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Triton thrasher - Here's a photo of a piece of clip wire pushed into a JCC/Emgo groove as far as it will go. The clip is riding on the corner of the pin and is not as secure.
Emgo pistons


Below is a piece of clip wire with a JE piston/pin. You can see that the bevel of the pin completely overlaps the clip and is secure.
Emgo pistons


Comnoz - Yes I raced with Hepolites when there wasn't another choice. But they would not even make it through a season before the ring lands loosened up and the top rings broke (on both pistons). Maybe I revved higher than others. So I developed the lightweight forged pistons (see 1980s photo below). They solved all my race problems with ring breakage and vibration/stress (crank and case cracking) because they are so much lighter. They are much smoother on the street.
Emgo pistons


Nortonspeed - when I said "JCC/Hepolite" I assumed that everyone would understand that JCCs are Taiwan knockoffs of Hepolites. Original Hepolites (UK) had good clips. JCC/Emgo (Taiwan) clips are junk.
 
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The Emgo piston is not machined for a wire circlip. They must be used with an original type clip.
The bottom of the groove is machined square. A wire circlip will work it's way into the flat floor and allow the pin to slip through.

And I have been experimenting with JE and Arias pistons since the 70's. Used them and Weseco's in a lot of different motors. In the 80's I was trying long rods and short JE's.

And even JE says a 2618 piston has a much lower wear index than a higher silicone forging or casting. They are soft and malleable. They don't crack as easy but the ring grooves sure wear out faster.
 
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jseng1 said:
oOnortonOo is right - the tangs on the JCC/hepolite clips are an accident waiting to happen. And they would rub on the flat of a pin even if the pin was chamfered - the pin would push out the clip at the tangs - then the entire clip would come out and eat away at the cylinder wall.

Go back and look at oOnortonOo photo of Emgo (?) wire clips on the previous page. You can see that the top clip is worn flat on one side from rubbing against the pin.
Click to expand...

NO, that's not what you are seeing.... The flat spot on the circlip in my picture is from the circlip rubbing the CYLINDER WALL. Marks from the two tangs were clearly visible where they scratched their points into the bore.
 
jseng1 said:
Maybe I revved higher than others.
Click to expand...

Maybe, like a lot higher, all the time? :rolleyes: Seemed to work well for you, though. I sure as hell couldn't keep up with you, nor could a lot of other folks, and you had some really good finishes.

"Those were the days, my friend, we thought they'd never end ...."

Ken
 
jseng1 said:
Triton thrasher - Here's a photo of a piece of clip wire pushed into a JCC/Emgo groove as far as it will go. The clip is riding on the corner of the pin and is not as secure.
Emgo pistons


Below is a piece of clip wire with a JE piston/pin. You can see that the bevel of the pin completely overlaps the clip and is secure

Nortonspeed - when I said "JCC/Hepolite" I assumed that everyone would understand that JCCs are Taiwan knockoffs of Hepolites. Original Hepolites (UK) had good clips. JCC/Emgo (Taiwan) clips are junk.
Click to expand...

Thanks that is clearer.

My experience is only with those awful Triumph twins. I bought clips advertised as original 1960s parts and I'm sure they fitted further down into the grooves than that.
 
The Emgo pistons I got for the Titanic from CHR came with Hastings rings and regular flat circlips. Those round-wire circlips look like death waiting to happen to me and I'd find some flat ones if that's what they came with. Just like the rings they are supplied with, there are far better alternatives at little relative expense.
 
What was the issue , if any , with seegar clips , could this be the problem with Taiwanese Heppolite-that the grove dimensions are copied from the original Heppolites and spring clips are fitted instead?
 
CP Carillo pistons use round wire circlips. No issues other than a little tricky to remove and fit.

Glen
 
worntorn said:
CP Carillo pistons use round wire circlips. No issues other than a little tricky to remove and fit.

Glen
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CP was started by guys who left JE, so they probably just used the same beveled pin and circlip arrangement as JE. As Jim Schmidt pointed out, when properly designed, that is a very secure system, and also the lightest weight one. FWIW, JE is also perfectly happy to machine their pistons for other pin locating methods. I've had them done in the past for Spiralocks, as well as for flat snap-rings, and in one case for double Spiralocks. But I've never had a report of failure with the wire circlips in the 19 years I've been selling JE pistons, so I'm sticking with that design.

On the other hand, there isn't any retainer design that can't be pounded out if you have something like a bent rod or out-of-line bore, except maybe aluminum buttons, but they are a lot heavier than any of the clip designs. And I'm not sure you couldn't eventually pound them out of shape too.

Ken
 
oldmikew said:
What was the issue , if any , with seegar clips , could this be the problem with Taiwanese Heppolite-that the grove dimensions are copied from the original Heppolites and spring clips are fitted instead?
Click to expand...

Emgo/JCC/Hepolite Norton piston kits seem to come supplied with seeger circlips (the original Norton spec.) and the circlip grooves are presumably machined for seeger clips, however, other Emgo/JCC/Hepolite piston kits (for BSA, Triumph, etc.) appear to come supplied with wire circlips (the original BSA/Tri. spec.) therefore those pistons should be machined for wire clips.

Triumph JCC/Hepolite example
Emgo pistons

BSA JCC/Hepolite
Emgo pistons


As comnoz pointed out, the problem can occur if the wrong circlips are fitted.
comnoz said:
The Emgo piston is not machined for a wire circlip. They must be used with an original type clip.
The bottom of the groove is machined square. A wire circlip will work it's way into the flat floor and allow the pin to slip through.
Click to expand...
 
L.A.B thanks for pointing out that you can still get Norton pistons machined for and presumably supplied with seeger clips.
 
LAB is correct in his observation i have a new set of 750 Hepolite JCC pistons which have seeger clips and grooves machined to suit the square section clip
they are also now fitted with UK made ring sets , it looks like someone has done thier homework and made improvements

i think best policy is to avoid old stock JCC pistons Cycle craft and old stock Emgo pistons will have the wire clips fitted
 
Hello, Together,
Until my retirement I worked in the German machine tool business. We had of course a lot of contacts with Chinese, but also Indian manufacturers. Believe me the companies we delt with, make absolute high quality products using our machinery (double face grinders). Here is an example: Piston rings were manufactured in India with a parallelism of the 2 plane- faces to each other of less than 0,002mm. That's the demand of the Japanese, the German and certainly also the American automotive industry. Mahle produces pistons in Mexico and the demands quality wise are the same as in Germany. Sealed Power in Mexico produces absolutely high quality piston rings.
I bought my set of JCC/EMGO 850 Commando- pistons from M.A.P and measured them. They were absolutely equal in every dimension that I could measure. Even the weight was equal to the last gram. Which says something about the quality of the wall thicknesses.
Years ago when I restored my first Atlas I bought a set of original Hepolites. There was a weight difference of nearly 20grams and the compression height had a difference of 0,3mm. Definately the quality of these JCC- Pistons is better than the old Hepolite- quality. Just for my own satisfaction I got the pistons with Hastings- Rings. Up until now the pistons withstand 7000RPM in top- gear with a final drive ratio of 21/38. Well, yes, I'm using a Suzuki GS 500 rear hub just because of the much better shock damping design of the rear sprocket carrier.
Coming to the point: Buy American, or Buy Brittish, or Buy German. This is all bullshit. Does anybody know how many parts in a car are made in China or India in our days? And does somebody know how expensive our goods would be if they were built in our countries? No, let these so called under developped countries have their business. That's the only way they can stay alive and that the people don't flood the world (from Mexico to the US or from Africa to Europe). But that's politcs and not our subject here.
But let me say one word about politics: Especially we in Germany had enough experience with racism. We learnt our lesson (at least I did). And just to finish the war with the Russians: I'm happyly married to a Russian woman. I have absolutely no prejudice to any nation in the world.
Best Regards
Klaus
 
Klaus Monning said:
Hello, Together,
Until my retirement I worked in the German machine tool business. We had of course a lot of contacts with Chinese, but also Indian manufacturers. Believe me the companies we delt with, make absolute high quality products using our machinery (double face grinders). Here is an example: Piston rings were manufactured in India with a parallelism of the 2 plane- faces to each other of less than 0,002mm. That's the demand of the Japanese, the German and certainly also the American automotive industry. Mahle produces pistons in Mexico and the demands quality wise are the same as in Germany. Sealed Power in Mexico produces absolutely high quality piston rings.
I bought my set of JCC/EMGO 850 Commando- pistons from M.A.P and measured them. They were absolutely equal in every dimension that I could measure. Even the weight was equal to the last gram. Which says something about the quality of the wall thicknesses.
Years ago when I restored my first Atlas I bought a set of original Hepolites. There was a weight difference of nearly 20grams and the compression height had a difference of 0,3mm. Definately the quality of these JCC- Pistons is better than the old Hepolite- quality. Just for my own satisfaction I got the pistons with Hastings- Rings. Up until now the pistons withstand 7000RPM in top- gear with a final drive ratio of 21/38. Well, yes, I'm using a Suzuki GS 500 rear hub just because of the much better shock damping design of the rear sprocket carrier.
Coming to the point: Buy American, or Buy Brittish, or Buy German. This is all bullshit. Does anybody know how many parts in a car are made in China or India in our days? And does somebody know how expensive our goods would be if they were built in our countries? No, let these so called under developped countries have their business. That's the only way they can stay alive and that the people don't flood the world (from Mexico to the US or from Africa to Europe). But that's politcs and not our subject here.
But let me say one word about politics: Especially we in Germany had enough experience with racism. We learnt our lesson (at least I did). And just to finish the war with the Russians: I'm happyly married to a Russian woman. I have absolutely no prejudice to any nation in the world.
Best Regards
Klaus
Click to expand...

I generally try to stay out of anything that's even close to political but I am with you 100% here. Both piston quality and prejudice wise. Me and my Mexican wife. Munoz is the noz part of comnoz. Jim
 
Klaus
Very refreshing, technically and philosophically.
Much more balanced and pragmatic than some of the BS put forward here.
Cheers
Rob
 
I agree with Klaus but as a German/Swedish/Irish/Scottish/English/Canadian I do experience great pride in riding my British bikes.
My personal motto is " The parts falling off this motorcycle are of the finest British quality"

Glen
 
Klaus, those are great words. Thank you.

And as mentioned earlier - one insisting on "buying only American" for your English bike is a bit ironic.
We purchase components for our builds and always support US suppliers when we can, but they are getting their stock from all over the world.

We fit Emgo pistons in almost every standard NYC Norton motor rebuild we do, and that's quite a few. With better circlips and Hastings rings, there has never been a problem. Ever. I have measured the EMGO pistons many times, and they measure so consistently it's almost hard to believe. (We also fit high-end forged pistons to some of the performance/race builds we do, and I have seen several piston variations of >.001" from our beloved American piston suppliers.)

As an aside: I have a set of EMGO 750 pistons here on my bench that I've just measured and weighed this morning, and they come in 9g lighter than the set of original Hepolites I've just pulled from a customer's motor (these Helpolites were extensively lightened by Ken Augustine, to boot). The EMGO pistons measure within .0002 of each other (that's two tenths of a thousandth).

-Kenny
 
after reading this post i have a sinking feeling .I fitted a pair of jcc pistons about 7000 miles ago with the supplied seger type circlips and have had no problems at all (so far) . Do you consider it wise or essential to strip the top end to replace the clips with those of alternative manufacture ? thank you in advance of your replies
 
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