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hepolite rings

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hepolite rings

Posted by thomas_martin at August 01. 2017

I have 2 v good hepolite pistons with ring i am not sure about no marking etc. what rings can i fit to the pistons +20 thou stamped on the head.

Re: hepolite rings

Posted by robert_tuck at August 01. 2017

What bike? ,earlier ones have different requirements, what rings do you have?.

Re: hepolite rings

Posted by thomas_martin at August 01. 2017

Previously robert_tuck wrote:

What bike? ,earlier ones have different requirements, what rings do you have?.

my bike is !955 88

I stripped the engine in 2002 so 15 years ago never had the time with work etc, but doing the house husband bit now so can do it between washing and shopping lol.

it had 8 rings per cylinder 2 compression in each grove and 4 oil control rings none marked with top or any dots. So as i cannot remember the order thinking of new rings standard +20 thou just want to buy the correct items

Re: hepolite rings

Posted by robert_tuck at August 02. 2017

Sounds a bit unusual, you will need to measure the ring grooves to check these have not been machined to fit the rings  in the past. I can't give you the sizes ,but someone else may be able to.  +20 ring sets do appear on E-Bay .

Re: hepolite rings

Posted by Gordon Johnston at August 02. 2017

Would they by any chance be a set of Cords rings? The description seems to fit.

Re: hepolite rings

Posted by thomas_martin at August 02. 2017

Previously Gordon Johnston wrote:

Would they by any chance be a set of Cords rings? The description seems to fit.

Possible but no marking. Tried fitting them the 4 thickest in the 2 compression slots and the other 4 in the oil control slot. just not sure as rings are flat faced no chamfers , so will get new just want to know what brad suits Hepolite pistons.

Re: hepolite rings

Posted by Barry Carson at August 02. 2017

don't know if this will help in some way

http://www.fwthornton.co.uk/8.html

Re: hepolite rings

Posted by Dan Field at August 02. 2017

I was thinking cord rings too!

Re: hepolite rings

Posted by thomas_martin at August 02. 2017

Previously Barry Carson wrote:

don't know if this will help in some way

http://www.fwthornton.co.uk/8.html

cheers will look at the site

Re: hepolite rings

Posted by robert_tuck at August 03. 2017

I think the lads are right ,Cords rings. They won't like being swapped around if used. They had a reputation for faster bore wear than std type rings, Its possible they may work if re-used ,on balance I would give them at try , although the fitting insructions say don't mix them up, but then I always have been a chancer.

Re: hepolite rings

Posted by Gordon Johnston at August 03. 2017

The reputation for rapid bore wear put me off Cords rings. They seem to be a short-term work-around for bore wear and high oil consumption. I have a set somewhere, never fitted. I just got ordinary ones instead.

Re: hepolite rings

Posted by robert_tuck at August 03. 2017

Its a slim possibility that normal rings may still work, spend some time checking piston/bore clearance and piston ring/piston clearance. But if the pistons are the slotted type ,best scrap them.

Re: hepolite rings

Posted by james_leadbeater at August 03. 2017

Hepolite 1977 catalogue.

1948/66 500cc OHV model 7/88/88SS.

Original Norton  piston and Hepolite 10338 piston.

Top compression ring 1/16 inch width.  Max radial thickness 0.105 inch.  Ref number MP 6201.

2nd ring sizes as top ring but ring numbe is  MPT 16017. Tapered???

Oil control ring 5/32 thick. 0.096 inch max radial thickness. Ring  number MEDO 9222

Hepolite ring set number  R3730.

If some clever soul has played with the piston or they are made cheaply in India or Tiawan or Italy the very best of luck in finding correct rings.

Radial depth is important especially for the compresion rings as the gap between the back of the ring and piston has to be correct if the ring is to seal the bore correctly and it requires the gasses behind the ring to do this. If the gap is too large or too small........ Unfortunately in my young days 'some' dealers flogged rings of the correct bore size and thickness only with no thought as to radial depth or even ring material etc. Of course it could be they knew nothing about the subject...or the customer??

Re: hepolite rings

Posted by thomas_martin at August 08. 2017

Previously james_leadbeater wrote:

Hepolite 1977 catalogue.

1948/66 500cc OHV model 7/88/88SS.

Original Norton  piston and Hepolite 10338 piston.

Top compression ring 1/16 inch width.  Max radial thickness 0.105 inch.  Ref number MP 6201.

2nd ring sizes as top ring but ring numbe is  MPT 16017. Tapered???

Oil control ring 5/32 thick. 0.096 inch max radial thickness. Ring  number MEDO 9222

Hepolite ring set number  R3730.

If some clever soul has played with the piston or they are made cheaply in India or Tiawan or Italy the very best of luck in finding correct rings.

Radial depth is important especially for the compresion rings as the gap between the back of the ring and piston has to be correct if the ring is to seal the bore correctly and it requires the gasses behind the ring to do this. If the gap is too large or too small........ Unfortunately in my young days 'some' dealers flogged rings of the correct bore size and thickness only with no thought as to radial depth or even ring material etc. Of course it could be they knew nothing about the subject...or the customer??

 

Thank you for your input all helps on getting it correct.

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