rebuild starts here

[steve_a]

Well after a bit of effort and a lot more time than hoped, we have finally reached the time where we are starting to put the series 3 back together.

At the moment we have the roof off, and the engine is basically in complete pieces. We needed to do the rear crank seal and after taking it apart it is clear we need to replace bearings on crank too.

Is it normal for the lower shells to wear more than the upper? all the lower shells showed copper, but the upper looked OK. I know the crank is not exactly light, so I guess I can understand this.

So after tonight we shall start reassembling the thing. Feels good to have gone as far as you can in breaking apart the engine, if I see an advert stating rear crank done I will have a lot of respect for them, this thing is WORK!

First order to Paddocks goes off tomorrow I think, new 050 Pistons w/ rings, we tried our best to measure the bore past the lip of coke, and the best we can come up with is we need oversize, so we have decided to go for the largest and and we can trim the rings down if need to.

Those 2.25 engines are tough little buggers, 2 pistons with broken rings, one of those had loads of gak in the inlet valve, the butterfly valvle was badly adjusted starving ti of air, a glow plug had gone (series wiring) which meant it wasn't preheating and all the shells were worn.

At least we are going from desctruction to construction now!

[Les Henson]

It is common for shells to be unevenly worn. The ltwt engine (2.25 petrol) had only the lower shells worn, and catflaps (2.5TD) bottom shells were down to the copper whereas the the upper ones were still ok.

When fitting over size pistons, you normally get the bore machined to match the pistons. Were the old pistons standard size?

Les.

[steve_a]

my poor late night typing les, we have measured the bore as best (we popped a ring below the coke and used a mic to measure that diameter and then measured the ring width), it came out IIRC at 90.63mm so we believe the pistons are standard size, but have been replaced before. Paddocks sell rings in oversize to make up the difference, going up in 010, which I belive is give or take 0.02mm.

So what I meant to say was we are going to get the standard size pistons with the oversize rings, and if the ring clearance is below what we can have we will just trim the ends a bit. The current gap was about 2mm on the rings, ROM says it should 0.25-0.38mm (2nd ring as it happened) so no wonder the starting was lousy.

It's good to hear that the bearing shells do seem to wear more on the lower side - I can see it happening, but still surprised.

[torrentace]

my poor late night typing les, we have measured the bore as best (we popped a ring below the coke and used a mic to measure that diameter and then measured the ring width), it came out IIRC at 90.63mm so we believe the pistons are standard size, but have been replaced before. Paddocks sell rings in oversize to make up the difference, going up in 010, which I belive is give or take 0.02mm.

So what I meant to say was we are going to get the standard size pistons with the oversize rings, and if the ring clearance is below what we can have we will just trim the ends a bit. The current gap was about 2mm on the rings, ROM says it should 0.25-0.38mm (2nd ring as it happened) so no wonder the starting was lousy.

It's good to hear that the bearing shells do seem to wear more on the lower side - I can see it happening, but still surprised.

[torrentace]

Make sure you confirm the availability of the pistons and rings before getting the machining done. I did mine out to plus 60 only to be told by paddock they were not available any more.

[Diff]

So what I meant to say was we are going to get the standard size pistons with the oversize rings, and if the ring clearance is below what we can have we will just trim the ends a bit. The current gap was about 2mm on the rings, ROM says it should 0.25-0.38mm (2nd ring as it happened) so no wonder the starting was lousy.

With all due respect, this will not work! You will waste a heap of money!

Oversized rings must be fitted to the same size oversized pistons, which must be fitted to the same sized oversized bores.

Oversizes come in increments, typically 10 thou ,20 thou, 30 thou and 40 thou. Not all oversizes are readily available, so check the availability of pistons and rings in the different oversizes BEFORE having machining done.

What you do is measure the bore, if it is too worn(diameter wise and/or oval), you take it to an engine machinest. He will rebore the block to the best oversize that suits the most worn bore of the four. Assuming he overbores it to say 20 thou, you then buy 20 thou oversize rings AND 20 thou oversize pistons.

I think a 4 cylinder rebore is about £90 to £100.

Hope this helps,

Regards,

Diff

[steve_a]

hmmm, You've got me wondering now, I assumed that the oversize element was the rings (since they sell oversize rings seperately) not the actual pistons (I have an old salt in the office with me who was leading me to this assumption when we were chatting).

If the pistons are oversize by that amount then we'll be screwed.

I will contact paddocks to check availability of everything, I was thinking I needed to do that anyway as I can't remember what the gasket set comes with, we need to do all the crank seals and I don't know if it came with them (I've had a set before but let most of it go since I only needed a few parts of it).

I'll have to look at reexamining the sizes if what you say is the case, we'd like to avoid a machining just on cost grounds.

We bought the truck for £300, everything was in good shape apart from a really smoky engine, we are trying to spend <£300 on parts (agreed project cost with the other halves:) ) to get a S3 that will probably be worth about £1500 we reckon. We are trying to avoid skimping on anything important so we have a good vehicle in the end, but the plan is to sell it fairly soon afterwards.

BTW whereabouts in Fareham are you? if you feel like proffering some advice... SimonB will probably be giving us some stick about short cuts as well since we work with him.

[Diff]

hmmm, You've got me wondering now, I assumed that the oversize element was the rings (since they sell oversize rings seperately) not the actual pistons (I have an old salt in the office with me who was leading me to this assumption when we were chatting).

If the pistons are oversize by that amount then we'll be screwed.

BTW whereabouts in Fareham are you? if you feel like proffering some advice... SimonB will probably be giving us some stick about short cuts as well since we work with him.

Hi Steve, in 'the old days' it was not uncommon to bodge old motorbikes(particularly 2 strokes) by getting an oversize ring to fit a standard piston in a worn bore, and file the ends to the right gap so that it fitted the bore. But believe me, it was a short term bodge that didn't always work, and it is still a bodge. You may waste a lot of time and money if you go this route. The oversizes should only be used together as I previously mentioned (and this is true for all engines of any make).

If you want to avoid a rebore and you have standard pistons/bores, then you should use standard rings. If the bore is not too bad, you can give the bores a quick hone and fit a new set of standard rings to your pistons(if they aren't too worn). Some of the current wear in the engine will be on the rings, so new rings might improve the engine a bit.

Any part rebuild like this, is only a 'freshen up' and its success and longevity will depend on the amount of wear present.

If you try to fit oversized rings in a standard bore by trimming the ends, the rings are 'squashed' in terms of diameter, more than they were designed to be, and there is a good chance they will break in service.

It is always difficult to do a 'cheap' rebuild and if cost estimates are escalating, you might want to consider purchasing a cheap second hand engine of known sound condition instead.

Yes, I know Simon, we have met a few times over the past few years. I live and work in Fareham itself.

I am always happy to help where I can. 'tinker time' is often limited these days as I have two young children.

I can usually be found here fairly regularly!

Regards,

Diff

[Phil Hancock]

Dont forget to glaze bust the bores if going down the re-ring or re-fitting of original piston/ring assemblies route, failure to do so WILL result in high oil consumption/smoke.

[steve_a]

Just trying to sort out glow plugs. The ones we pulled are the pigtail ones, and in my ignorance I ordered the same set of glow plugs as for my last series. However the ones that arrived were too small a diameter for the head.

From the parts manual it appears that 568335 are the pigtail ones, and that ERC8450 are the bulb type ones. I guess we can just do a like for like and order the older type in (the ebay seller LRSeries (gb7916) is happy to return and send the right ones). How would we use the newer type? Helicoil the head or something?

The vehicle is about a 1981, so I'm surprised it doesn't have the later head, however, with the damage to the pistons from broken rings etc I think it may have been swapped for a good older one. Certainly the valve guides are nice and tight and the valve stem seals were only on thier way to being mistaken for a metal part...

I was also looking at the crank bearing bolts - £12 each! I think we may skip that part of the replacement parts, since that would be £150 just by themselves.

Makes me wonder about looking at the 2.5 we had with it, the bellhousing has a missing part, but it looks like we could just bolt our 2.25 housing straight on if needed, which might mean the starter motor will work too.

[Phil Hancock]

Makes me wonder about looking at the 2.5 we had with it, the bellhousing has a missing part, but it looks like we could just bolt our 2.25 housing straight on if needed, which might mean the starter motor will work too.

If your 2.25 is a 5 bearing unit then yes the 2.5 bellhousing will fit, if it is a 3 bearing unit then no it wont fit.

[steve_a]

bum.

Took the block to engineering place today and it looks like we would need to take it to 030 to be certain, the coke ring was not a coke ring, it was wear in the bore.

So I guess we will start looking at the 2.5NA, first step is to look at getting it started on the engine stand so we can see what it runs like.

Need to look for some information on the conversion, at the moment a new engine mount is needed, but I don't know about clutch, and flywheel.

We will probably need to use the starter motor from the series, are the flywheels the same, or will we have to change that?

I'm hoping we don't end up at plan C or even D(for dismantle), she's a nice old girl and I don't want to strip her for parts (although I was going to do that originally).

We may have a 2.25 older style head which appears in decent condition, a crank and some other bits and bobs from the 2.25 if anyone is looking for bits. Won't be certain they are free until we check the 2.5.