Author Topic: cylinder liner thoughts  (Read 2420 times)

Online sean

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cylinder liner thoughts
« on: 02.01. 2021 19:57 »
just honing the cylinders to clean them up and noticed several deep pits near the top ...cylinders are at plus .060 and I am not sure going to plus .080 will clean these up , they are fairly deep and this side of the cylinder had a broken valve guide in the head .
the bike sat for 10 years and was seized when I got it striiped it down and rebuilt everything but just saw this .
my options are paying for a rebore that may or may not work ,cylinder liners or trying to find a used set of barrels ......be interested to hear opinions
1962 super rocket
thanks

Online sean

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Re: cylinder liner thoughts
« Reply #1 on: 02.01. 2021 20:00 »
Here is a pic

Online KiwiGF

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Re: cylinder liner thoughts
« Reply #2 on: 02.01. 2021 20:20 »
just honing the cylinders to clean them up and noticed several deep pits near the top ...cylinders are at plus .060 and I am not sure going to plus .080 will clean these up , they are fairly deep and this side of the cylinder had a broken valve guide in the head .
the bike sat for 10 years and was seized when I got it striiped it down and rebuilt everything but just saw this .
my options are paying for a rebore that may or may not work ,cylinder liners or trying to find a used set of barrels ......be interested to hear opinions
1962 super rocket
thanks

I would get liners fitted, my GF has them and no problems, you can rebore them once as well. The type with locating “ledge” at the top (to ensure they don’t move) are worth fitting for peace of mind.

You or engineer would have to get the grinder out to make slots for the rods.

Just my 2 cents worth.
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Offline ellis

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Re: cylinder liner thoughts
« Reply #3 on: 02.01. 2021 20:28 »
Hi sean,

I had a similar problem on my 1660 A10. i decided to put new standard stepped barrels in. The good thing with stepped barrels is you dont get any movement with them as the cylinder head traps them in position. Also you have nice thick walls so in future you will get at least three rebores out of them.
Cost wise mine only came out a few pounds less than having them bored to maximum and buying a new set of pistons.

ELLIS

Offline Scott and Jay

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Re: cylinder liner thoughts
« Reply #4 on: 03.01. 2021 00:08 »
Yes, chiming in to agree with KiwiGF. I was also at +60 thou". The "flanged" liners (with the "ledge" at the top) weren't available anywhere. Then Adrian Wright, the proprietor of IMD pistons (which I have also been recommending) - came up with some. They just need to be cut off at the bottom..

Online sean

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Re: cylinder liner thoughts
« Reply #5 on: 03.01. 2021 02:34 »
I found the liners on their web site and e bay but I dont see a flange on them ?
do they have to be honed or bored after fitting as I imagine they would be a press fit  ?
seems they have a machine shop a couple of hours from me in Canada they deal with according to the web site .

thanks
Sean

Offline BSA_54A10

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Re: cylinder liner thoughts
« Reply #6 on: 06.01. 2021 09:13 »
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 .
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Online sean

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Re: cylinder liner thoughts
« Reply #7 on: 06.01. 2021 13:47 »
was going to do that today .....found a set of barrels std size but I think they are from an Ariel huntmaster they have no casting numbers and the Bsa Ones have the part number [ 67- 1210 ] cast into them.
 I belive the fins are different between the 2 types not sure how to identify the ariel one for sure and I think they are interchangable , but I am going to pass.

Sean .

Online muskrat

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Re: cylinder liner thoughts
« Reply #8 on: 06.01. 2021 19:51 »
G'day Sean.
I'd be going for liners. Straight ones are OK if their given enough interference. 1 thou per inch is about right. The materials are very similar being spun ci in cast ci so thermal expansion is very similar and the liner will heat up more and faster than the barrels so will not move.
This will also give your grandkids a re-bore or two ;)
Cheers
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Offline Swarfcut

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Re: cylinder liner thoughts
« Reply #9 on: 07.01. 2021 10:01 »
   Sean, as a cheapskate those pits don't look too bad. To raise the ire of the precision engineers among us, is filling with braze and polishing back a reasonable solution to restore this small area of an otherwise good bore?

 Swarfy.

Online sean

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Re: cylinder liner thoughts
« Reply #10 on: 07.01. 2021 13:54 »
cylinders have about 100 klm on the according to previous owner they were rebored before he stored the bike

Offline RDfella

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Re: cylinder liner thoughts
« Reply #11 on: 07.01. 2021 15:42 »
Swarfy, I normally agree with all you say, but filling with braze? I'd rather leave alone.
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Online Triton Thrasher

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Re: cylinder liner thoughts
« Reply #12 on: 07.01. 2021 16:59 »
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.

Online sean

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Re: cylinder liner thoughts
« Reply #13 on: 07.01. 2021 18:14 »
Thanks for the replies
Going to go with liners got too much money in this to cheap out now just have to find a supplier hopefully in Canada but not looking good so far and no replies yet from Uk..........being on pension sucks .

Offline RDfella

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Re: cylinder liner thoughts
« Reply #14 on: 07.01. 2021 18:23 »
"Practically all the compression sealing should be done by the top ring." Especially those engines that only have one compression ring!
'49 B31, '49 M21, '53 DOT, '58 Flash, '62 Flash special, '00 Firestorm, Weslake sprint bike.