Engine rebuild ...

Post by **JustinMinor1000** » Fri May 12, 2006 10:08 pm

So this has turned out to be a whole heap of fun ..

I didn't realise quite how easy it was to take engines to bits ..

The engine has not run for at least 20 years and is very very siezed.

I took the head off and except that two of the push rods got stuck in thier tubes everything seems fine except ...

All the pistons are "Down" .. they are all (+- 10mm) 50mm front he top of the block ..

Am I going to find something horrible when I take the sump off ?

Post by **bigginger** » Fri May 12, 2006 10:13 pm

All down at the same time, and all the same? I hope not - that's very, very wrong - 2 should be 'up' near the top of the bore, and 2 should be MUCH lower than that

Post by **bmcecosse** » Fri May 12, 2006 10:39 pm

Sounds like it's just stopped in mid stroke. You should soak some diesel fuel oil down each bore to help loosen off the pistons - leave soaking for at least a week ! DO NOT - try to force them to move ! But it will be a miracle if it doesn't need reboring and new pistons - the crank may well be ok though.
How can the push rods be stuck ? It will just be dried up cack - wiggle them about and pull them through.

Post by **JustinMinor1000** » Sun May 14, 2006 2:20 pm

bmcecosse wrote:Sounds like it's just stopped in mid stroke. You should soak some diesel fuel oil down each bore to help loosen off the pistons - leave soaking for at least a week ! DO NOT - try to force them to move ! But it will be a miracle if it doesn't need reboring and new pistons - the crank may well be ok though.
How can the push rods be stuck ? It will just be dried up cack - wiggle them about and pull them through.

It stopped exactly mid stroke .. I've put a picture on my webpage

http://mogpics.mysite.wanadoo-members.co.uk/

I'm now in trouble with this engine ..

It was dirty and seized .. However the seized is obviously due to standing .. All the pistons have end float and the cam shaft has movement against the chain .. Therefore it has to be one of the main bearings ..

I now have two choices ..

Take it all to bits and replace the rings and big ends and main bearings .. (Ie make a big job of it) .. or just free it, clean it and stick it in Pod and rebuild the engine that comes out .

How much end float should I have in the pistons ?

Half of me can't believe that I've taken an engine this far to bits only to reassemble it without any new bots .. the other half can't believe I'm thinking of messing around with such a good engine ..

Post by **bigginger** » Sun May 14, 2006 2:26 pm

Strange - never seen that before

Post by **rayofleamington** » Sun May 14, 2006 5:32 pm

I guess you need to keep going untill you find what is siezed...
If the pistons move freely up and down (not just side to side) and the crank is serviceable then yes you could try putting it all back together and running it

Are you sure that the rings are not stuck to the bores? That could allow some piston movement but virtually no crank rotation.
However you might find something nasty on the crank bearings so my feeling is that the jury is still out as regards whether it is a runner or a rebuild job.

I took the head off and except that two of the push rods got stuck in thier tubes everything seems fine except ...

Often thje pushrod will lift the cam follwer out of the bore when it is picked out - this can be a real pig depending on how easy you can get to the tappet chest covers (don't do this with an LCB fitted!!). Best practice is to 'wiggle' the pushrod around until you know the cam follower 'bucket' is no longer stuck on the other end - this way you will leave the cam follower where it is meant to be.

Post by **bmcecosse** » Sun May 14, 2006 6:50 pm

Highly unlikely the crank has seized. Don't understand the bit about camshaft moving against the chain ??? And what do you mean by piston 'end float' ??? The rings will be stuck in the bores - if you force it you will snap the rings /possibly ruin the pistons/probably ruin the bores. You must get it freed off. Almost no chance you will get this engine running with any chance of reliabilty without spending money on it. You MAY get away with new rings and new crankshaft shells - that's about the minimum spend (~ £80 allowing for gaskets) - or you may need a rebore and new pistons, and a crank regrind with new shells - in which case be sure to fit a new oil pump!! That will cost ~£ 200 depending on what you have to pay for new pistons these days. Ask Bullmotif.
You have to ask yourself - is it worth it ? When you can pickup a 'runner' for between £25/50 - sometimes even free!

Post by **rayofleamington** » Sun May 14, 2006 8:38 pm

camshaft moving against the chain ??? And what do you mean by piston 'end float' ???

pretty simple?
The cam can rotate as much as the slack in the timing chain allows therefore cam is not seized.
Pistons can move a bit in the bores - therefore not melted/stuck to the bores.

Post by **JustinMinor1000** » Sun May 14, 2006 9:12 pm

Yes it takes a bit of explaining ..

I'm sorry .. I've confused you all with this and the reason is because I took some advice ...

When I got this engine I asked a mate of my father in law to have look at it .. (it was allegedly out of a very low mileage car ...)

Said MOFIL trys to turn it over and proclaims that the crank is certainly siezed "Because if it was the pistons there would some movement"

Just because someone has a load of fifties and Sixties cars rotting in their front garden DOES NOT MEAN THEY KNOW ANYTHING ABOUT MECHANICS ...

(Reminder to self .. Write that out and frame it and stick it to the wall of the garage ..)

So .. I assumed it was one of the bearings .. I took off the sump and tried to move each piston in turn each one would slide left to right a nats .. so I assumed it was not that. Therefore as the camshaft would move slightly .. I assumed it was not that either .. So as it couldn't be the pistons .. it must be the main bearings ..

Of course it wasn't the main bearings .. IT WAS THE PISTONS ..

I HATE KNOW IT ALLS ...

A trip out to the stables to get half a litre of red

Bores are now soaking in diesel Tommorow I'll have to put the main bearings back together and try and turn it over ..

And given that the engine stopped mid stroke .. The bolt's for pistons 2 and three are inaccesable .. So the best idea might have been to fill the pistons with diesel and try and turn it over .. Do I remember someone giving me that advice some time ago ? No I must have imagined it ..

Post by **JustinMinor1000** » Sun May 14, 2006 9:38 pm

bmcecosse wrote:You must get it freed off. Almost no chance you will get this engine running with any chance of reliabilty without spending money on it. You MAY get away with new rings and new crankshaft shells - that's about the minimum spend (~ £80 allowing for gaskets) - or you may need a rebore and new pistons, and a crank regrind with new shells - in which case be sure to fit a new oil pump!! That will cost ~£ 200 depending on what you have to pay for new pistons these days. Ask Bullmotif.
You have to ask yourself - is it worth it ? When you can pickup a 'runner' for between £25/50 - sometimes even free!

Money is not the primary consideration .. Education is pretty high uo there too I've changed an engine on a Landrover before (which is not saying much as with a 2.5 litre engine you can have a picnic between the front of the engine and the radiator) but never on a moggie ..

Pod's engine is Ok'ish .. a bit of tappet rattle .. slightly low oil pressure.

Since this engine came my way I thought it would be a good idea to see if I could rebuild it .. Then as opposed to spending £3-400 on a "Rebuilt" engine or £8-900 on an ESM rebuilt one (Which might be cheaper in the long run) ...

The possibility that I could simply replace the bearings and piston rings and have a known good engine appealed to me .. a £25 second hand engine is an unknown quantity ..

Having spent £1500 having a "Rebuilt" engine put in my VW ten years ago .. for the big ends to go after a month and a half .. (On a 30 day guarantee naturally) to be told that they do not replace the big end bearings as a matter of course .. With this engine I would know EXACTLY what had been done .. and if anything was wrong then I was the only one to blame ..

Post by **bmcecosse** » Mon May 15, 2006 7:30 am

Right - so it is the rings that have stuck - diesel should loosen this up - but it takes a while. Gently rock the crank back and forth each day and add more diesel. The pistons presumably have side play - not end play . This just means they are able to move in the rings - but the rings are stuck fast. Cranks/cams etc only seize if the engine has been lying exposed to rain for a while. If you can do the strip/rebuild yourself then it should still only be about £200 total - unless piston prices have increased hugely in recent years. Check with Bullmotif.

Post by **rayofleamington** » Mon May 15, 2006 7:23 pm

Are you sure that the rings are not stuck to the bores? That could allow some piston movement but virtually no crank rotation.

well I'll try not to join the know it all party ;-)

You don't have anything much to loose (apart from time) by removing the main bearings for inspection. If you also remove the 2 big ends that you can access, you should 'in theory' be able to move the crank to the other side (180 deg rotation) to undo the remaining 2 big ends. How easy this is in practise is a different story and does also involve removing timing chain.

Post by **bmcecosse** » Mon May 15, 2006 9:04 pm

If the rings are stuck tight the crank won't rotate without being able to move the pistons - which are being held by the stuck rings! Why need to remove timing chain ??

Post by **JustinMinor1000** » Tue May 16, 2006 9:49 am

bmcecosse wrote:If the rings are stuck tight the crank won't rotate without being able to move the pistons - which are being held by the stuck rings! Why need to remove timing chain ??

I'll take a Photo .. What ray says is exactly what I was considering .. I need to take the timing chain off and the "Support bracket" and then the crank should as ray says rotate so that I can remove the two remaing big ends ..

Post by **bmcecosse** » Tue May 16, 2006 10:47 am

Ahh - if you take it out of the main bearing housings ! All is clear!!

Post by **JustinMinor1000** » Tue May 16, 2006 6:49 pm

The pistons are Moving ... Don't seem to have made any damage to the bores ...

Do the pistons have to come out through the top ? or can I drop them out of the bottom ?

Post by **rayofleamington** » Tue May 16, 2006 6:58 pm

The top is the normal way. Not 100% sure if they clear the bottom ok - it is different between different types of engines and once the rings have popped out there's no going back...

Post by **bmcecosse** » Tue May 16, 2006 9:50 pm

Well done - told you the diesel would fix it! Pistons out the top only.