Author Topic: cylinder liner thoughts  (Read 971 times)

Online Triton Thrasher

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Re: cylinder liner thoughts
« Reply #15 on: 07.01. 2021 18:59 »
"Practically all the compression sealing should be done by the top ring." Especially those engines that only have one compression ring!

Racers!

Offline BSA_54A10

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Re: cylinder liner thoughts
« Reply #16 on: 10.01. 2021 08:36 »
Do a quick fit up and check where he pits are with respect to the top of the top ring.
Most of the compression is done by the second ring in an case .

Practically all the compression sealing should be done by the top ring.  The second plain ring does some useful oil scraping.
The top ring is called he fire ring for good reason, it takes he brute force of the combustion
The first set of gapless rings I installed I fited the gapless one on the top and they failed myserably
Swapped them around, gapless 2nd ring, worked like a dream

According to some conversations with Total Seal, they suggest opening the gap on the top ring and closing the gap on the 2nd ring regardless of weather  am using gapless or standard rings.
Too little gap on the top ring  prevents suffcicient gas pressure getting behind the second ring fast enough to create a proper seal.
 has been taught the top did all the work but apparently it should be the 2nd.
In use I have run more than one engine with pitting in the bore because new barrrels or liners were beyond my finances at the time
Unless the pit wa almost a full ring, the worst case was an engine that was a little more smokey than it should have been.
Bike Beesa
Trevor

Offline BSAmoto

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Re: cylinder liner thoughts
« Reply #17 on: 12.01. 2021 11:14 »
One of my quick Norton engines exploded long ago and left a few dings in the upper end of the LH barrel. I rebuilt the engine without reboring the barrels as they were not worn out - except the dings. Ran a hone through and put used pistons in. No smoke as the dings cannot collect oil - they are all above the upper travel end of the oil scraper ring. So check location, if yours are as high up the barrel as they appear, I would use as is.

Offline BSA_54A10

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Re: cylinder liner thoughts
« Reply #18 on: 14.01. 2021 08:13 »
Swarfy, I normally agree with all you say, but filling with braze? I'd rather leave alone.

S O P with large marine deisels
Bike Beesa
Trevor