pdm
|
| posted on 17/11/09 at 06:27 PM |
|
|
Measuring ring gap
Evening all,
After posting on here not too long ago about measuring clearances, I finally got round to measuring ring gap on my practice engine last night. But
it's raised a couple more questions if I can....
Firstly I used some piston ring pliers and it sort of (how can I put this politely) stretched the ring quite a lot. As a result the gap when it was
just lying on my bench was quite a lot more than when it was loosely fitted around the piston - is this normal or will it have lost some "return
spring" ?
Secondly I did as suggested on here and placed the ring in the bore and pushed it down a bit with the piston. It's quite hard to
"set" it into the bore ready to push with the piston without scoring the bore - is there any technique ? (I saw a youtube vid where the
guy quite casually tossed them in and then just used a piston to square them. Also I didn't want to drag it back out the top again in case I
scored the bore so I used the piston to push it out the bottom of the block - is this ok ?
I've tried to be as paranoid as possible about scratching/nicking either the bore or the piston hence the questions.
Thanks in advance.
Paul
|
|
|
|
|
mookaloid
|
| posted on 17/11/09 at 07:00 PM |
|
|
It sounds to me like you might have knackered the rings  once you have stretched it beyond it's elastic phase you will have weakened it and if
it was mine I wouldn't want it back in the engine.
The using a piston to push the rings in and out of the bores is fine.
I think you need a new set of rings, and be careful when gapping them!
"That thing you're thinking - it wont be that."
|
|
|
thunderace
|
| posted on 17/11/09 at 07:09 PM |
|
|
i would not use the ring as you have abuseds it 
the rings will be weakened badly and fail very fast..
|
|
|
pdm
|
| posted on 17/11/09 at 07:40 PM |
|
|
Cheers for the responses...
I don't see an easy way of removing the rings without knackering the elasticity - what's the proper way of doing it ? Or is it generally
accepted that the rings are binned in any rebuild.....even if they are I've still got the problem of how to install a ring without over
stretching it ? I tried re-installing a ring last night as well and the pliers stretched it so that the diameter of the ring was more than the piston
so it went straight into the ring landing....
(BTW - the engine's pretty much scrap and I got it for a £10 so I'd much rather try a few things out on this one than a "real"
one !!).
|
|
|
Peteff
|
| posted on 17/11/09 at 07:52 PM |
|
|
Put one of the old rings in the groove while you fit the next one down. Lever them in with a thickish feeler gauge blade running it round the piston.
It's ages since I did any but I never broke one and they worked fine in the engines they were fitted to.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
|
|
|
Angel Acevedo
|
| posted on 18/11/09 at 02:56 PM |
|
|
Its been a while since I assembled an engine, but, ring pliers are the way to go, just don´t try to get the ring in one go, spread just enough to
clear one end and work your way around the piston.
At least this is the way i used to do it with no problems.
Beware of what you wish.. for it may come true....
|
|
|
