2.6 engine help/oversize Pistons

[morty]

G'day folks, I have pulled the head off my 2.6 engine which comes out of a 5 door 2a station wagon. Engine is a runner but blew blue smoke and all cylinders had compressions around 90psi. I squirted some over down the cylinders and this resulted in a increase of pressure. I thought this warranted further investigation.

When I pulled the head off there is no shoulder at the top of the stroke and I can still see cross hatching from I presume which would be from a recent rebuild. I was wondering if anyone could help my identify what oversize cylinders are in my engine? Or what else could be causing this oil burning and low cylinder pressure. I think they are 30thou oversize maybe but I thought the rings only came in 20thou, 40thou......?? I will post a picture below. Thanks for the help.

Cheers, Hamish

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[Blknight.aus]

check the piston slop,

it may not have been ringed correctly,

it may have dicey valve settings or hinky valve stems and seals.

[gromit]

I had problems where the motor had been 'dusted' and the rings were badly worn.

FFR Refurb (https://www.aulro.com/afvb/leaf-sprung-military-land-rovers/118730-ffr-refurb.html)

If there is no ridge and you can see cross hatching you'd think the rings were OK.
As Dave mentioned, it could be valve guides or the seals in the inlet guides.

Pistons used to come in +.010, .020, .030, .040 & .060" but it depended on the aftermarket as to what was available for what motor. Yours appear to be +.030"

I hand scraped the wear ridge, honed & fitted new rings in mine. Also fitted new guide seals and re-seated the valves. Doesn't smoke now, but to be fair, it hasn't been used in anger.


Colin

[67hardtop]

Maybe someone lined up the ring gaps like in my diesel engine i recently rebuilt. Not lined up now of course...lol

[morty]

Thanks everyone for the help. I will investigate further and see what the go is. Pulling out the pistons should narrow things down a bit. Hopefully there won't have to be full rebuild like I was expecting maybe just a tidy up and make sure everything is reasonable order.

Cheers, Hamish

[1950landy]

May have been over teated at some stage & rings have lost there tention & as some one else said check the ring gaps are not inline . They need to be 180 deg to each other & top away from the exhaust valve.

[UncleHo]

Hi
Yes,over heating can cause the rings to loose tension,which results in poor starting,smoking,lack of power,if that is the problem a new set of rings is the only way out

Cheers

[morty]

Hi all,

To avoid letting things get out of hand I am tackling one section of the engine at a time, starting with the head. I am thinking of taking off the rockers so I can take the head into town and get someone to look at the valves and see if the head needs milling flat.

However I have run into trouble with getting the rocker shaft out. In the parts book it is split into two sections apparently and according to the manual you need special tool No. 262749. It looks as one half will come FWD and the second half will come AFT. I have removed the 3 locating screws on the which secure the rocker shaft.

Just wondering If anyone has had success with extracting the rocker shafts without the special tool. If so, how did you do it?

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Thanks, Hamish

[russellrovers]

Hi all,

To avoid letting things get out of hand I am tackling one section of the engine at a time, starting with the head. I am thinking of taking off the rockers so I can take the head into town and get someone to look at the valves and see if the head needs milling flat.

However I have run into trouble with getting the rocker shaft out. In the parts book it is split into two sections apparently and according to the manual you need special tool No. 262749. It looks as one half will come FWD and the second half will come AFT. I have removed the 3 locating screws on the which secure the rocker shaft.

Just wondering If anyone has had success with extracting the rocker shafts without the special tool. If so, how did you do it? hi i have a good 6 engine here if you need ji

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Thanks, Hamishihave a motor here jim

[Blknight.aus]

rubber hose, a small insert tube and nuts bolts and washers.

slot the threaded end of the bolt (you may want to do this AFTER you assemble the tool

get a nice long bolt, slide a washer in, slide some insert tube on and then feed the rubber hose section over the top of that.

add another washer and a nut.

slide it in bolt head first, tighten the nut onto the bolt assembly using the slot you cut as a screwdriver slot for a flat head.

As the nut winds onto the bolt the rubber expands inside the rocker tube and will get a grip, out she pots.

[morty]

I ended up being able to get the shafts out by using a ezy-out attached to a sliding hammer. One came out very easily and the other required a few light taps. 149004149005

I then removed the rockers, bagged and labeled them individually. Used a magnet to remove the collets.
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Pulled out the valves and by the looks last time it was apart o-rings did not get put back in the valve stems. No wonder it was blowing some smoke. I thought the valves and seats looked in really good nick.

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All is going well so far, Cheers. Hamish

[Blknight.aus]

I thought the valves and seats looked in really good nick.


All is going well so far, Cheers. Hamish


I concur on both counts

[1950landy]

The special tool for extracting the rocker shafts is a easy out welded to a "T" handle . I have a drawing of one here some were . I will see if I can find it & post it up for you along with a drg for the special tol to keep the timing chain tentioner .

[morty]

Just wondering if anyone knew what the standard thickness of the thrust washer on the 2.6 engine is?
My pair of washers give me the correct end float but one of them has been brass soldered to beef it up a little and is wearing unevenly. I used verniers and measure the un-tampered one and it measures 0.0920 thou. Would is be the standard? Maintenance manual and parts catalogue gives the oversize increments but not the standard width.

Cheers, Hamish

[morty]

My parts for the engine rebuild have rocked up today. Had to get old new stock from the UK as parts for these engines were bloody hard to get. New .030 thou rings, new inlet and outlet valves, new inlet and outlet valves, .010 thou oversize big end bearings, timing chain wheels and engine overhaul gasket set.

Unreal service from P.A Blanchard from the UK. Very helpful and have a huge range of genuine 2.6 parts.

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Hamish

[Homestar]

Yes, it took me a few years to get everything for mine at prices I was able to afford. Got a box of expensive bits but haven’t rebuilt the engine yet... Still on my to do list.

Keep the info and pics coming, following with interest. 👍

[morty]

G'day. Picked my block and head up from the engine shop on the weekend with the honing and the valves cut to the correct angles. The owner of the shop said they have only seen 1 of these engines in 40 years. I suppose you could take that a few different ways haha.

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?
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Also bought some oversize thrust washers and honed them down with some wet and dry to get the correct end float on the crankshaft. Was sitting at 2 thou after the first adjustment (pictured below) and ended up getting it to 5 thou.
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Cheers any help,

Hamish

[Homestar]

I’ve thought about the piston fitting myself although I’m far from that stage. Would something like a modified standard piston ring compressor work with bits cut out to follow the shape of the block?

[gromit]

I reassembled without a ring compressor, just used my fingers.

FFR Refurb (https://www.aulro.com/afvb/leaf-sprung-military-land-rovers/118730-ffr-refurb.html)

The top (angled) part of the bore is a slightly bigger diameter so no need to cut down a piston ring compressor, it should tuck into the top section.


Colin

[cjc_td5]

I assembled the piston assemblies from underneath on my 2.0l siamese bore (sloped head) block.

Does the big end of the rod fit down the bore? It doesn't on a 2.0l so installing all from underneath is much easier.

[Blknight.aus]

use feeler gauges or shim plate with lots of oil

[rover-56]

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

[1950landy]

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.

[morty]

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

[1950landy]

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

[cjc_td5]

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?

[morty]

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

[morty]

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.

[Homestar]

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.

[morty]

I had a look this afternoon homestar are reusing the spacer with the new oil control rings. However the new rings are .019 thou smaller in width than the old ones. Do you reakon this would matter? I think the old ones are defiantly toasted as I put one into the bore and it wouldn't even stay there on its own haha.

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I think my pistons may be aftermarket as the part number stamped into the top there doesn't match anything in the book. Maybe why the original oil control ring set doesn't fit. Does anyone have the inner diameter measurement of where the oil control rings sit on a original piston? A .030 thou oversize piston but a standard would also do.

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Cheers, Hamish

[Homestar]

How do they fit in the bores? If there is tension and the ring gap is ok, I’d go for it, but ultimately you need to be happy with your decision.

[67hardtop]

How did you assemble the oil ring? Wavey ring should be first as its the expander, then crimped ring, oil control. Then top and bottom split rings hold the lot together. The top and bottom split rings fit into the crimped ring and as such dont actually touch the inside if the piston groove but do touch the top and bottom, respectivly, of the piston groove. Did you check piston to bore clearance first? Did you then check compression ring gap in the bores? If all good then you can also check the split oil rings fit ok in the bore if u want too. The oil ring "assembly" should fit ok as it will comperss. Is the oil ring fitting in the piston groove ok? Check also comperssion ring fit in grooves. If the oil ring is too sloppy in the piston groove u have a problem.

I see ur using old pistons. Make sure the grooves are cleaned of carbon deposits as well.
Cheers

[Blknight.aus]

assemble the rings off the piston and use the piston inverted to push the rings down the bore, check the gap with a feeler every half inch or so.

this is the only time you line up the gaps on the oil rings.

[Busted Syncro]

G'day All,
Interesting thread.
Can I suggest you contact the ring manufacturer Brico Engineering UK. (link: Brico Engineering Ltd. | Coventry | England | ENGINEER SCOUT (https://www.engineerscout.org/company-brico-engineering-ltd-in-coventry-18480)) and see if anyone can remember the correct way to assemble the ring set in particular the oil control ring assembly. They may have documentation they can send you.
Chris

[1950landy]

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.

153486
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 think you will find the crimped ring is fitted 1st then the two oil rings with the wavy ring between the two oil rings to keep them seperated as per the photo of the piston.

[cjc_td5]

You need to push the ring down in to the bore with the skirt end on the piston, as the top of the piston top is not flat?
assemble the rings off the piston and use the piston inverted to push the rings down the bore, check the gap with a feeler every half inch or so.

this is the only time you line up the gaps on the oil rings.

[Busted Syncro]

G'day All,

Now it's starting to get interesting. Learning never stops when you have a LandRover!

This is the link to Mahle oil control ring installation: YouTube (https://www.youtube.com/watch?v=WVTOsYWfkuk)
The crimped ring is a Radial Spring as shown in the video.

However, where the wavy ring (spacer) goes is of concern. Hopefully the manufacturer can advise the correct install placements.

Chris

[Blknight.aus]

You need to push the ring down in to the bore with the skirt end on the piston, as the top of the piston top is not flat?

you are correct, I frequently forget that when dealing with slant head setups...

most times its the skirt end thats got the wavy cutout.

[morty]

Cheers for all the help. I ended up taking a piston and the rings to a aircraft engine rebuilder who had rebuilt some of these engines years ago. It ended up being the right way. The ring compressor did squeeze them in enough to get them into the bores. Got all the pistons in.

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Ended up getting the cam in as well. Bloody hell it was a bit tricky to get all those half moon soft metal bearings located in the right spot. Had to use some cable ties to hold them together while getting the cam in.

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Dropped off the flywheel to get in machined and trying to find out some part numbers for the 2.6l clutch plate kit. I believe is the RVK-6003 for the exerdy clutch kit. The old clutch is a 9.5 inch plate. However it doesn't have the 1/4 spacer under the slave cylinder which I have seen mentioned as an indictor to need the 9.6 clutch plate. May have been left behind somewhere year ago.

[Homestar]

Where did you get the new cam from and what are its specs compared to the original? Cookey gave me some specs years ago for a new cam but I haven’t managed to get hold of him about who he got the cams made through.

[morty]

Homestar. I reused the old cam. I did a visual on all the bearing surfaces and bearings and they looked good. I bought a replacement bearing for the very front longer bearing as it had a few scoring marks in the soft metal. If your chasing a cam I have 2 donor engines. Unsure of the condition however.

[morty]

Unrelated to the 2.6l rebuild but took my 2.25 petrol ex telecom landy for a run around this saturday up the highest place at home. Generally went really well but has a few snags. Pics for those who are interested.
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[morty]

So got my engine all back today this weekend. I got the side valves in and timing sprockets and chain in a while ago. All went pretty well. Put a new Iwis timing chain in it. I was surprised of the good condition of the brass coolant directors, they cleaned up really well.

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One thing that was interesting was these cast aluminium brackets that the inlet rockers rub up against. On the engine I had pulled apart someone had made washers to shim these brackets out to avoid the side spring pressure slowly bending these brackets inward and causing uneven wear. You can see the difference between two brackets below (the bent one is from another spare parts engine, on the right). This was a good mod I reakon and reinstalled them the way they came out.

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Got the head torqued down and the other bits and pieces onto it. Just ordered a carby rebuild kit and another clutch plate and it should be good to go I reakon.

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[morty]

So got the engine back in pretty smoothly over the past week and took it for its first run today. Went really well. Small road blocks was getting my head around the metering needle centring on the stromberg cd175 carby. I also forgot to reinstall 4 bolts where the engine stand was installed behind the flywheel, which was devastating when I had to split the gearbox and engine again hahaha. A couple of coolant leaks first up but they were soon rectified. Some photos of her all back together for those who are interested. Next thing is historical rego hopefully.

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