Thread: 2.6 engine help/oversize Pistons

Originally Posted by morty

I am trying to get my head around how I will get the pistons back into the bores when I get around reassembling the engine. I have heard you need a special piston ring clamp to ensure the rings don't get caught in the cavity where the exhaust valves are. Has anyone done this before you know of a tool you can make?

Hamish

I use a piece of 0.25mm shim steel rolled to the piston dia. with a worm drive hose clip.
The shim drops in to the top of the bore and the piston and rings slide right in.
Terry

I use a normal ring compressor , just tap it down all the way around it will go out of shape then gently knock the piston down making sure compressor doesn't come out of the bore.
The compressor will go back into shape once taken off the piston. I have had my ring compressor for 50 years & have pistons in a number of IOE motors with it & it is still working fine. You just need to be carefull & take things slow. I have also fitted the pistons on a 1595cc motor from the bottom when the crank shaft was out.

Cheers for the help everyone. A bit further down the track when I get to that stage I will have a play around. Last night checked the big end bearing caps for their clearance without the bearings in place and then afterwards checked the bearing nip. All within the range. When I pulled the engine apart there where small brass shims under one side of the bearing caps. Guessing these were for getting the nip correct on the last set of bearings I suppose?

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Cheers, Hamish

So did you put them in through the top or bottom & what did you use as ring compressor.

Originally Posted by 1950landy

So did you put them in through the top or bottom & what did you use as ring compressor.

If he was just checking big end gaps, he probably hasn't got rings in yet, so just slid in from the bottom?

Originally Posted by 1950landy

So did you put them in through the top or bottom & what did you use as ring compressor.

I Haven't got the rings in yet just checking the big end bearing nip. I will have to put the cylinder in from the top I think as the block casting gets in the way on the bottom.

Cheers, Hamish

G'day. This morning was looking at installing the new compression and oil rings and I have run into a problem. The .030 oversize oil ring set which I have bought come in 4 pieces.
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The Old ones were a set of 3 components.

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I checked the clearance of the 2 small flat oil rings and they were correct .015 to .033 thou. However when I install the crimped ring, the wavy ring and the 2 flat oil rings it just seems way to big and won't fit into the bore. The inner crimped ring seems like it is far too big. Will the crimped ring compress enough to fit into the bore? The gaps on the 2 flat oil rings are huge!

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The part numbers are correct. So with a compression ring installation tool will these compress enough and fit into the bore? I hope the photos make things a little clearer.

Thanks for any help,

Hamish.

I have come across similar issues with other engines over the years and I have in 2 cases used the old crimped spacer with the new oil control rings to get things to fit as they should due to the new ones being too tight once the rings were fitted. Not sure why this happens or if there are multiple piston designs in some engines and the replacements are made off one kind or the other, but that’s just a guess - I didn’t have issues with either engine either in service doing this. Check to see if it all goes together like that. Maybe not the way it’s supposed to be done, but could be an easy fix.