The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Crossrodes on May 04, 2009, 01:37:31 PM

Title: Compressing Piston Rings And Cylinder Base O-ring
Post by: Crossrodes on May 04, 2009, 01:37:31 PM
OK the O-ring first.  

I bought new O-rings for my 79 r65.  I think the first one went in OK (won't know until I fire her up).  However I'm having a problem with the second one.  It seems to be too big for the cylinder.  When it is installed a part of it sticks out of the groove.  I can get it all in but it is an extremely loose fit.  Is this normal for these o-rings?  When I ordered the rings I got the part no. off the fiche....is it possible that I received a ring for a larger bore bike?

Re the ring compressor...someone posted a suggestion that I use a hose clamp as a ring compressor.  The problem was that all the clamps I could buy were not wide enough.  I tried the widest clamp I could buy but because it couldn't cover all the rings at once I couldn't get it to work.  Fortunately I was able to manually compress the rings on one cylinder with my fingers and get the cylinder on.  With the other cylinder however, I cannot get the second ring compressed.  

Has anyone got any other ideas as to another tool I could fashion or can you recommend a compressor tool that is available commercially and who would you recommend purchasing from?

Mike
Title: Re: Compressing Piston Rings And Cylinder Base O-ring
Post by: Bob_Roller on May 04, 2009, 02:24:36 PM
The o-ring should be a snug fit, if it hangs out, it will get cut and not provide any sealing.

Were the o-rings packaged separately, any part numbers on the packaging, sounds like you got one that is for another bike.

Do you have any zip ties / ty-wraps, may be able to compress the ring enough to install it.

I know they can be installed by hand, without any special tools, but the rings are quite sharp, and you will cut up your fingers in the process.
Title: Re: Compressing Piston Rings And Cylinder Base O-ring
Post by: Lucky_Lou on May 04, 2009, 03:09:36 PM
The rings i got from motorworks were all labeled with correct installation notes as there is a chamfer on the inside to the piston ring you can get oversize rings but they are special order. i had problems trying to use a ring clamp in the end i fitted the pistons then slid the bore on over the rings as there is quite a big chamfer on the engine end of the cylinders they went on easily enough and all is running OK now done about 150 mikes on em
Lou
Title: Re: Compressing Piston Rings And Cylinder Base O-ring
Post by: Crossrodes on May 04, 2009, 03:31:30 PM
Unfortunately I've thrown out the packaging that the O-rings came in so I can't check the part numbers.  If I can't get the piston rings into the cylinder and have to order a ring compressor I'll order new O-rings also.  If I can get the piston rings compressed I'll try seating the cylinder with the present O-ring and see how it works.

I don't mind buying new O-rings; the problem is that it takes forever to get parts shipped up here to Canada.  I can buy parts at a dealer about 100km away but I recently checked the price of a particular part and it cost $47 here in Canada and about $7.50 in the States.  I think you can understand whey I don't like buying parts here.

Thanks for the advice.

Mike
Title: Re: Compressing Piston Rings And Cylinder Base O-ring
Post by: Lucky_Lou on May 04, 2009, 03:40:30 PM
The way i did it was with the cylinder on the bench in a vice then entered the piston from underneath untill the rings were fully engaged then mounted the cylinder on the head bolts lined up the crank at TDC  fitted the gudgeon pin and its retaining clip bolted down and Bobs your uncle
Lou
Ps the clymer manual shows the internal chamfer on the rings and the correct way round but the haynes manual i have does not mention this
Title: Re: Compressing Piston Rings And Cylinder Base O-ring
Post by: Crossrodes on May 04, 2009, 05:50:52 PM
Thanks for your feedback guys.  I installed the cylinder...only when I fire her up will I know if the cylinder base O-ring is doing it's job.

I didn't have any zip ties that were long enough to compress the piston rings so I decided to try something else.  I managed to get the first (compression) ring in with my fingers.  I couldn't get the next one in so I decided to try the hose clamp trick on the next two rings.  The hose clamp was wide enough to cover these two and when I tightened it down then pushed the cylinder in it just slid right in.  This method seems to work quite well.

Lucky Lou, I used the Clymer manual for reference and followed the diagram regarding the rings.  I had them in the right way.

Now I have another question about valve train needle bearings...I'll start another thread.
Title: Re: Compressing Piston Rings And Cylinder Base O-ring
Post by: MrRiden on May 04, 2009, 06:55:11 PM
Poverty riders tool tip. Combine a strip of metal from a cat food can [you can leave the rim on] underneath your hose clamp for a nifty ring compressor. Discovered this trick when re ringing my first car, a Triumph Herald. Always worked and always at hand.
Title: Re: Compressing Piston Rings And Cylinder Base O-ring
Post by: Landlubber on May 04, 2009, 11:43:44 PM
Mr Riden,

As I do not have a cat, I was wondering if dog food cans would be OK, or would the engine not purr well if I did this?
Title: Re: Compressing Piston Rings And Cylinder Base O-ring
Post by: Justin B. on May 05, 2009, 01:10:59 AM
It might wind up with a sort of growling noise at low RPM...  [smiley=2vrolijk_08.gif]
Title: Re: Compressing Piston Rings And Cylinder Base O-ring
Post by: vestandpants on May 05, 2009, 01:52:42 AM
This thread has given me paws for thought ...

Ill get my coat, TAXI
Title: Re: Compressing Piston Rings And Cylinder Base O-ring
Post by: Justin B. on May 05, 2009, 09:40:21 AM
All right, enough of the punny comments lest we have him barking up the wrong tree.  Get back to work...  [smiley=whip.gif]
Title: Re: Compressing Piston Rings And Cylinder Base O-ring
Post by: Lucky_Lou on May 05, 2009, 11:23:48 AM
Had a root round the workshop found my old rings saved as they werent bad in the packet with the instructions heres a link to the scan as the file is too big to load on here
http://s278.photobucket.com/albums/kk113/luckyloudiamond/?action=view&current=ScannedImage.jpg
you should be able to zoom in on the info
Lou
Title: Re: Compressing Piston Rings And Cylinder Base O-ring
Post by: Justin B. on May 05, 2009, 11:40:11 AM
Did you get the three piece oil rings with yours?  I got the one piece and I've always felt the three piece were better at controlling oil...
Title: Re: Compressing Piston Rings And Cylinder Base O-ring
Post by: Lucky_Lou on May 05, 2009, 05:24:08 PM
Quote
Did you get the three piece oil rings with yours?  I got the one piece and I've always felt the three piece were better at controlling oil...
That one is a one piece ring with 2 scrappers ive not done alot of miles on it yet but it seems ok to me.
Lou
Title: Re: Compressing Piston Rings And Cylinder Base O-ring
Post by: Rob Valdez 79 R65 on May 05, 2009, 06:54:45 PM
I've never needed anything except my fingers to install a cylinder over the piston rings.
I don't recall hurting myself.
Title: Re: Compressing Piston Rings And Cylinder Base O-ring
Post by: Justin B. on May 06, 2009, 01:16:20 AM
Lou, that looks like the same set I got from Moto-Bins that I put in the '82 LS...
Title: Re: Compressing Piston Rings And Cylinder Base O-ring
Post by: MrRiden on May 06, 2009, 07:06:34 PM
Quote
Mr Riden,

As I do not have a cat, I was wondering if dog food cans would be OK, or would the engine not purr well if I did this?
WHAT? No cat? I advise you to immediately go out and purchase several!!
 ;D
Title: Re: Compressing Piston Rings And Cylinder Base O-ring
Post by: nhmaf on May 06, 2009, 09:14:29 PM
Quote
Quote
Mr Riden,

As I do not have a cat, I was wondering if dog food cans would be OK, or would the engine not purr well if I did this?
WHAT? No cat? I advise you to immediately go out and purchase several!!
 ;D

What!!!!   PAY for a cat?!?!?   'Round here you can get 'em for free unless you want some special breed.  
Title: Re: Compressing Piston Rings And Cylinder Base O-ring
Post by: Landlubber on May 07, 2009, 11:28:26 PM
Actually I love cats, I work in China, it has become one of my favourite foods, Chicken Chow Meow.
Title: Re: Compressing Piston Rings And Cylinder Base O-ring
Post by: montmil on May 09, 2009, 06:23:59 AM
Quote
Actually I love cats, I work in China, it has become one of my favourite foods, Chicken Chow Meow.
;D ;D ;D  Too funny. I often annoy my litter box acquaintances by referring to their other white meat.   Monte