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Oil control piston rings, do i really need them?

Posted: 18 Jul 2010, 10:22
by fix
Well ive hit another stumbling block when rebuilding my 2.1 engine.

The new oil control rings for the pistons are slightly too wide and wont fit, the rings are for a 1.9 engine rather than 2.1 so i assume thats why they are slighlty wider.

Can anyone let me know if im ok leaving them out? One of the old ones has broken in half so unfortunately i cant re use them.

If anyone can reply letting me know i would appreciate it, i really wanted to get the pistons and liners back on today.


Thanks

Re: Oil control piston rings, do i really need them?

Posted: 18 Jul 2010, 10:54
by CovKid
Yes you do need them. They help distribute oil in the bore and partially reduce oil working past piston rings but without them you'll undoubtedly get premature wear. A rebuild is a lot of work as it is, but leaving them out will be an expensive omission in my view. It could also cause rapid wear of the piston skirt, though never having tried it, I can't confirm.

Re: Oil control piston rings, do i really need them?

Posted: 18 Jul 2010, 10:58
by Titus A Duxass
Of course you need them.
As Covkid stated they are for oil control.
VW didn't put them there for fun.

Re: Oil control piston rings, do i really need them?

Posted: 18 Jul 2010, 11:02
by fix
Just what i didnt want to hear :cry:

I just asked as i know on some motorbikes ive had before the oil control rings werent really necessary (i know its not exactly the same but they were still pistons).

I can get some 2.1 rings from euro car parts but they cost £50, on top of all the other extras this rebuild has needed its getting very expensive!

I thought people used 1.9 rings as 2.1 were harder to get hold of, are the oil control rings normally a different size ie people use their old ones and just replace the top two?

I assume getting hold of a used ring is a bad idea.

Re: Oil control piston rings, do i really need them?

Posted: 18 Jul 2010, 11:27
by fix
Well Euro car parts are £50 a cylinder not a set, but as luck would have it ive found a set for £20 delivered.

Hopefully then i can finally get my engine put back together :D


Just as a matter of interest can someone confirm the 1.9 and 2.1 oil ring sizes are slightly different?

Re: Oil control piston rings, do i really need them?

Posted: 18 Jul 2010, 18:18
by billy739
the bore diammeter is different so the rings will be the wrong size/ arc

Re: Oil control piston rings, do i really need them?

Posted: 19 Jul 2010, 11:48
by Red Westie
As a side note* don't forget to glaze bust the bores otherwise the new rings will never 'run in' to the shape of the worn cylinders and use lots of oil etc.

Martin

Re: Oil control piston rings, do i really need them?

Posted: 19 Jul 2010, 20:31
by fix
Cheers yes i will be giving them a good rub with that stuff thats on the bottom of washing up sponges (cant remember to actual name but you get what i mean!)

Re: Oil control piston rings, do i really need them?

Posted: 19 Jul 2010, 20:38
by toomanytoys
billy739 wrote:the bore diammeter is different so the rings will be the wrong size/ arc


Bore size is the same for all 1.9 and 2.1 engines.. its the stroke that is different.. + the different pistons for stroke difference and compression ratio differences depending on what "flavour" engine you have...

You could reuse your old oil rings.. if they look pretty good and check them for gap in a barrel.. the oil rings dont wear as much as they see more oil than the other 2... place the gap upper most... then the other rings at 120 degrees either way to that

Re: Oil control piston rings, do i really need them?

Posted: 19 Jul 2010, 21:03
by Red Westie
A scouring pad or even scotch brite isn't going to give you the course horizontal key hatching needed to properly run in the rings.
New barels come cross hatched from the factory so that the piston rings bed in properly and over a few thousand miles.

TOOL LOOKS LIKE THIS;

http://cgi.ebay.co.uk/GLAZE-BUSTER-PIST ... 1e5d0493c2" onclick="window.open(this.href);return false;

Martin

Re: Oil control piston rings, do i really need them?

Posted: 19 Jul 2010, 21:07
by kevtherev
As red westie says or a similar thing...

you can get a honing kit to freshen the bores up

Image

cost around £15

Re: Oil control piston rings, do i really need them?

Posted: 19 Jul 2010, 21:18
by purpletony
Try Volkspares for the rings
i had same problem
found them to be a lot cheaper
and top quality at the time

Tony

Re: Oil control piston rings, do i really need them?

Posted: 23 Jul 2010, 12:43
by fix
I already put the pistons into the liners before I read what youve put about honing.

I used some 400 grit wet and dry on the liners to rough them up abit, didnt use any particular pattern just did them all over.

I take it that may not do the job?

If im risking the rings not bedding in properly i will have to remove them and buy a honing kit, although i finish my job next friday and lose my company car, my only transport is going to be the van so im really running out of time to get it done!

The new oil rings ive got are abit different to what I expected, they are in two pieces and include a seperate spring which i have put in the middle of the two rings, where as the old oil rings and the wrong oil rings I got were in one piece with the spring in the middle that was covered up, on the new rings it just sits in the middle and isnt covered up.

Is it correct i should just put the spring in the middle of the two rings?


Thanks

Re: Oil control piston rings, do i really need them?

Posted: 23 Jul 2010, 19:15
by fix
Well ive just decided to buy a deglazer, ive taken the pistons i put in last night out ready to do the liners tomorrow. Machine Mart sell the deglazer so I will pick one up in the morning.

Can anyone confirm about the oil rings? Its just ive never seen them like that before, i cant understand why the springs arent covered up when on the other rings they are.

Thanks

Re: Oil control piston rings, do i really need them?

Posted: 23 Jul 2010, 21:06
by Plasticman
http://www.49ccscoot.com/bbk.html" onclick="window.open(this.href);return false; first thing I could find but its pertinent, your three part ring is as they suggest often best fitted by sticking the spring (bendy/wavy) one in first then as you stated thin ring either side.
I gather your in a hurry as you need your wheels but do it wrong and you will be doing it again
Mike