Hepolite piston ring installation notes


Hepolite ring installation pdf file

Hepolite rings are made in England and are not sold under any other name brand. This premium ring set is comprised of a two piece oil ring with coil spring , a cast iron second compression ring, and pvd faced top compression ring. Anyone not familiar with this ring set or using a two piece oil ring may benefit from reading these notes.


This top ring has been PVD chromium nitrided on its face. The oval marking on the ring indicates the top and should be installed with the marking towards the combustion chamber.

Hepolite compression ringSECOND COMPRESSION RING

The second compression ring is coated with a black phosphate, and is marked TOP to indicate that it should also be installed with the marking facing the combustion chamber.

Hepolite compression ring


The most modern oil control ring ever produced for the vintage Triumph!

There are a few things to know about installing an oil ring with a spring expander.

First- the free gap of the oil ring in the cylinder without the spring installed is not important, as the actual surface tension comes from the coiled spring behind the ring. This ring design is superior than one piece as the radial distribution of pressure is even across the circumference of the bore. It is also chrome nitrided on the face for longer life and reduction of friction.Hepolite oil ring

Also- the expander spring has a gap that can be opened slightly to install on the piston. The oil ring is then installed over the spring, and the spring must be 100% behind the oil ring before the piston is installed.

Hepolite rings Made in England


To check ring gap insert ring on bore and square it accurately in the cylinder. Check the end gap with a feeler gauge. Adjust gap squarely with a file or ring filing tool. Be sure to deburr the end of the ring gap after file fitting so no sharp edges are present. Suggested ring gaps are .004”to .006”per inch of bore for top and second ring. The oil control ring expander creates the tension, so the free gap of the oil ring alone is not important, only that the coil spring is installed correctly.

If re-ringing without boring it is important that you check the ring gap in the least worn part of the cylinder. RINGS MUST NEVER BE SPIRALED ONTO THE PISTON To install the rings on the piston open the gap only enough to get it over the piston, while keeping the ring perfectly flat. Never twist or spiral a ring as it will damage the ring, increasing blow-by and reduce oil control.

Cylinder honing cross hatch finish


Cylinder finish is extremely important to the seating of your rings. We believe a 220 grit finish will work for this ring set, which can be obtained by using Sunnen M27-J55 (AN 300) stones. With the PVD coated top ring, a 280 grit using M27-J65 stones (AN 500) would work well too. Talk to your machinist or best resource about what is best for your application.

 Make sure your cylinder is absolutely clean before installation, and the rings are not damaged while installing the cylinder.We prefer to lightly lubricate the rings and ring lands with non detergent 30w oil and lightly coat the cylinder bore so it won’t rust. Stagger the ring gaps so they are not lined up. Make sure the expander ring gap is 180 degrees from the oil ring gap. When compressing rings during final assembly it is imperative that the rings are not scratched, bent, or distorted. Oil on the rings will not harm ring seating, as internet folklore suggests.

Hepolite piston ring packaging


There are as many opinions about breaking in rings as there are religions. We don’t usually have problems with seating rings mostly due to our level of detail in preparing cylinders, and correct ring installation. DO NOT use synthetic oil for break in. Use a conventional oil with no friction modifiers. We use Penngrade1® SAE 30 oil for break in. DO NOT idle the bike any more than necessary on startup. This will do nothing but create heat, which will not be dissipated by the new rings until seated. Rings need compression and a load on them to seat. DO NOT lug the engine, ride in abnormally hot weather, or in congested traffic. Vary the engine RPM while keeping between 1500-5000, and go for a short ride. Let the engine cool and check your base nuts, head bolts, and valve adjustment in that order.


If you are uncertain about any of these above procedures, there is a wealth of information about piston rings on the internet. We suggest that you look at different piston ring manufacturers websites for additional information. With the right cylinder preparation, correct end gaps, and proper installation techniques, your rings should break in quickly and provide you with a long service life.


Hepolite ring installation pdf


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