if I wanted to fit new rings to my pistons would it be madness to attempt it with engine still in the car?

I think the steps are

1. oil and coolant drain
2. exhaust off
3. head with inlet manifold off
4. sump off
5. oil strainer off
6. undo conrod bolts
7. lift piston and conrod out
8. light hone?

new rings

new conrod bearing shells 030105701G

new conrod bolts 052105425A

reassenble is reverse of above

How tough is it to put the pistons back in with new rings and a piston ring compressor, fit shells, end cap, tighten bolts, rotate the crank repeat - while lying on your back?

It's do able! just if you do hone, then you've got the problem of making sure the bores and crank are clear of any crud afterwards

yeah its plenty doable , your steps seem to cover it

Only issue I can see is avoiding getting metal dust/slithers stuck to the oily bits.

It makes life easier if you put the car on ramps before you start work.

There is no earthly reason why you shouldn't do this work laying on your back - once the oil has stopped dripping!!!

Check the piston ring grooves before fitting the new rings, each groove should be reasonably 'square' (free from wear) - Clean out the ring grooves with an old broken piston ring used as a scraper.

My favored method of removing/fitting rings is to place some protective soft jaws in the vice (or use a Black & Decker Workmate) - allow the piston skirt to sit on top of the vice jaws and gently grip the con-rod. This keeps the piston firm whilst you change the rings. I know that there are tools on the market for expanding the rings (some people advocate using feeler blades) but I have always had success positioning the ring gap towards me, putting the middle fingers of each hand at the back of the ring to support it and use my thumbs to open the ring gap JUST far enough to clear the piston lands (parts between the grooves) and the crown. DO NOT over expand them or you may break the rings - Be prepared to get some 'dents' in your thumbs though!!

If you are going to hone the cylinder bores, protect the crankshaft by covering with newspaper or cloth - Take care when removing this so that you don't deposit any swarf on the crankshaft.

As you say, you will need a piston ring compressor of some sort when putting the pistons back in.

Make sure that you keep the big end bearing caps paired to their own con-rod AND keep them the same way round as originally fitted.

Regards.

Thanks for the info everyone. A Graham Bell says the ring gaps should be staggered.

Good old Haynes says to pre check the top 2 piston compression ring end gaps are 0.30 to 0.45mm (and bottom scaper ring gap less than that) by placing the rings 15mm from bottom of bore - then file the ends if gap too small.

But the crankshaft will be in the way won't it?

But the crankshaft will be in the way won't it?

Given the Polo's square stroke I suppose it's only 70mm or so from the top!

yeah shouldnt be too much bother ...have you priced up the parts though?

What Mr Haynes is saying is that you measure the ring gaps by placing them in the unworn part of the cylinder (NEAR the bottom - exactly how close to the bottom is unimportant) Square up the ring by pushing it down the bore with a piston (without any rings on it, obviously) and then measuring the ring gap from the top, using a feeler gauge.

Yes, the ring gaps should be staggered when you assemble the engine, but they do in fact move around on their own when the engine is running.

Regards.

Measure at unworn part - then it doesn't matter much which cylinder and I only need to measure one ring - assuming they all start equal circumference - and base everything off that?

Yes I'm aware they rotate just keep them out of phase to begin with.

I was assuming the rings would take up some of the wear/match the ovalness I expect to find though valve guides now suspect.

Just found out the cost of oversize pistons. £220- each

My hot engine dry compression test gave 85psi across the board - was hoping for 115+ as 8bar is stated wear limit.

so try a wet comp test and if its great that does point at worn rings

been reading up they say this style honer is much better as it can follow any slight ovalality etc much easier

http://www.ebay.co.uk/itm/Flex-Hone-Cylinder-Ball-Hone-320-Grit-46-48mm-Tool-/171021683646?pt=Motors_Automotive_Tools&hash=item27d1afcbbe

just a random ebay link you can get em cheaper

You need to hone your bores out make sure you put a crosshatch Patten back on the bores when you are done

Not sure how to do the wet test.

I managed to pour oil on the floor- not into the sparkplug hole which did not help.

Using a tube I think it landed in the piston crown depression then got blown out doing the 6 pumps of the reading.

Are you meanty to squirt the cylinder walls through the sparkplug hole?

Guess I need a helper to be able to watch the gauge, not juts look at final recorded pressure.

been reading up they say this style honer is much better

You need to hone your bores out make sure you put a crosshatch Patten back on the bores when you are done

stevo's flex-hone gives the cross hatch pattern. Cool.

Looks like 2 & 7/8 inch for 75mm bore.

Eight inch shaft.

What's not to like?.

Which grit coarseness?

Edited 5 March, 201412 yr by dvderlm

I'm far from an expert , i understand the wet test is a couple of squirts from a oil can to wet the walls via the plug hole, easier if you dont have a dish in the piston i guess

240 grit on those ball hones , let me know if you find any in the uk

I made a request for quotation with pace-high but I fear they are trade and will want to sell me 144.

Just because of how easy it is to take an engine out, versus a day of poor light, bad back and lumps of oil landing in my eyes, I'd drop the engine out and do it on the bench.

Dropping it out -okay, but lifting it back up and in on my own - erm?

... besides I don't have a bench!

Anyway I thought gearbox downwards but engine upwards with a hoist/crane. Or can I lift the car over the top of the dropped engine?

should be able to drop it out on a decent jack if you can raise the car enough

do you have any helpers though, I'm fairly hefty and cant really lift an engine on my own to shift it far

cough cough I've heard a second hand shopping trolley /diy store cart can be modified to carry an engine around , they're available for cheap

could also look at engine stand , buy it and keep it clean should re sell for similar money , but again you will need help getting it that high to bolt it up

Edited 7 March, 201412 yr by steveo3002

Thought the sump would collapse on a jack - suppose it's steel not alloy.

That's inspired. And only a quid from aldi... at least I think that's what the coin slot is for.

Actually I could hire an engine crane for the weekend. But if it has to come out then it's re-bore time.

240 grit on those ball hones , let me know if you find any in the uk

Pace-high got in touch. They have in stock and will sell ball hones singly for about 68 quid, delivery extra.

So I've ordered 2 plus honing oil from an amazon based US dealer so should have 1 for sale when they arrive

(end March?)

Edited 7 March, 201412 yr by dvderlm

sump is fine , can use a block of wood to help spread the load

another handy thing if youre rolling the engine about with no proper lifting gear- an old used tyre ! you can sit the engine in it , or use it as a buffer if you need to tip it on its side etc

Getting closer to starting this.

Think my ball hones arrive tomorrow. But now I read I may need a ridge reamer to remove the built up ring of carbon at the limit of the piston's travel in order to get the pistons out easily without damaging the ring lands.

Only American websites seem to care about this... anyone know the truth?

Dropping it out -okay, but lifting it back up and in on my own - erm?

... besides I don't have a bench!

Anyway I thought gearbox downwards but engine upwards with a hoist/crane. Or can I lift the car over the top of the dropped engine?

I just get the car nice and high supported by the jacking points and drop the engine, box and quite often the exhaust out the bottom on a big trolley jack, then separate it on the floor. If you've got the exhaust off, the engines are really shallow, so you can rock them forwards and pull them out under the front valance easily enough. Dropping them onto a bit of old carpet and using that as a handle to pull by works well.

A crane's not essential by any means, I only use them to lift the engine and box back in, and if no one's about for a lift, to put the engine on the bench.

is there a ridge there ? or engine still in use

my abd I've got in the shed , id say its done a fair few miles judgeing by the coked up head - thats got no lip at all at the top

Still in use. It's still my daily.

Thanks for the carpet hint Yeti. Got some floor vinyl that might work.