Piston rings issues

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swampy42
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Piston rings issues

Post by swampy42 »

Engine rebuild in progress. Feeling a little like a fish out of water. I've just inspected all the piston rings, They all look in fine shape apart from the top one on one cylinder, which has about 8-10mm snapped off. Is this amount of imperfection worth worrying about, or do I have no option really but to buy a whole new set of piston rings for all 4 cylinders? Can you buy rings individually? Also, there is 2007 stamped into the top of the piston - does that mean the piston was manufactured in 2007? If I do end up having to buy a new set of rings, there are about half a dozen different sizes for the 1098 engine from ESM, how can I discover which will fit mine? Many thanks in advance.
Russ
bmcecosse
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Re: Piston rings issues

Post by bmcecosse »

Hmm - where did the 8/10mm go ???? Did it snap when you were removing the piston - or cleaning the ring grooves. It's a LOT to consider a full new set - maybe someone will have a spare ring they could give you.
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martin418
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Re: Piston rings issues

Post by martin418 »

no 8 to 10mm missing from a ring is a definite no go , you need at least a set of rings but what are the cylinder bores like , i guess there a ridge at the top indicating bore wear ,
swampy42
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Re: Piston rings issues

Post by swampy42 »

The little bit of the ring just fell out as the piston was removed. There doesn't seem to be any scoring or marking of the cylinder, although I must confess I haven't examined it closely as yet - that's a job for next weekend. How do I determine if my piston rings are 'standard'. Is it just a case of measuring the bore diameter?
bmcecosse
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Re: Piston rings issues

Post by bmcecosse »

Yes - the pistons may be marked STD - otherwise the absence of any other marking such as 020/030/040 etc. Your '2007' is slightly odd - maybe it indicates a 20 thou oversize........
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swampy42
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Re: Piston rings issues

Post by swampy42 »

Well, there goes that plan. I was planning on re-using the rings, but then SNAP! . . . . I guess I'll have to get a new set now.

As far as I can tell, they are standard sized rings, insofar as there isn't any markings saying otherwise. The pic below shows the markings on the piston, does anyone in the know have any idea if these tell me a size change from standard?

The bore size according to my 'christmas cracker' calipers is 64.55(ish), so I guess I'm looking at a standard diameter bore. Just need confirmation that I'm not missing something.
Thanks in advance
Russ[frame]Image[/frame]
bmcecosse
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Re: Piston rings issues

Post by bmcecosse »

Standard original pistons - 'Grade' 2 - but that's not significant now. Are the ring grooves and bores worthy of new rings ?
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swampy42
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Re: Piston rings issues

Post by swampy42 »

The bores look OK to me. Pic below which may tell you otherwise. I wouldn't say there's no lip at the top of the stroke, but I don't think it's significant.[frame]Image[/frame]
swampy42
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Re: Piston rings issues

Post by swampy42 »

The ring grooves are something I haven't considered - I'll try and take a pic of them when I get a mo. What is the Alternative to new rings if the grooves aren't up to scratch?
bmcecosse
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Re: Piston rings issues

Post by bmcecosse »

New pistons...in which case - may as well get a rebore. But these bores look fine..... Still no offers of a few spare rings?
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swampy42
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Re: Piston rings issues

Post by swampy42 »

Afraid not. I feel stupid asking this, but if a ring has broken why can't it be reused? Will the area where it has snapped become deformed?
I should add that I don't intend to use a broken ring - I was just curious.
Here's the grooves pic[frame]Image[/frame]
Last edited by swampy42 on Thu Sep 18, 2014 1:13 pm, edited 1 time in total.
swampy42
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Re: Piston rings issues

Post by swampy42 »

-
bmcecosse
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Re: Piston rings issues

Post by bmcecosse »

Grooves look fine. The ring is springy and gently leans on the bore... If snapped in two - obviously no 'spring' - just flapping about... I found some oil rings from a 998 Mini engine (same bore) - but not what you need I guess.
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swampy42
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Re: Piston rings issues

Post by swampy42 »

Sadly not. I need the top two rings. If it ends up that I have to buy a new set, do I have to do anything to the bore to accept the new set? I seem to remember reading something about a glaze busting tool?
bmcecosse
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Re: Piston rings issues

Post by bmcecosse »

You should indeed glaze bust - but rough paper on a stick moved up and down on a 45 degree swirly pattern will do the job perfectly well. I amazed no-one has an old/spare piston /rings for you..... :cry:
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swampy42
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Re: Piston rings issues

Post by swampy42 »

Would emery paper be OK, or is that too rough?
I'll put another post into the wanted section for the rings I think - last one must have been overlooked.
bmcecosse
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Re: Piston rings issues

Post by bmcecosse »

Emery is good. Ask for a complete piston too...
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win
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Re: Piston rings issues

Post by win »

Hi
I have a couple of spare rings, STD. diam, 1.6mm or .062" thick. Where are you???
You can have them if they are any use to you, PM me with your address, and I will post to you.

Regards Win
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swampy42
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Re: Piston rings issues

Post by swampy42 »

WIn
PM sent. That's really good of you - many thanks indeed. The rebuild's back on . . .

Cheers
Russ
bmcecosse
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Re: Piston rings issues

Post by bmcecosse »

There you go! What a great forum!!! Now - do you know how to fit them without snapping them....?
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