Moved The Crank With The Head Off!

[c_r_thomson 0]

 

The engine is out and the head is away for a clean, I took off my old clutch and stupidly hadn't locked the flywheel. As i was undoing a rather tigh clutch bolt, the flywheel rotated a fair bit and therefore the pistons moved 2"-3".

 

2 questions,

The liners look ok and seem level, do you think it's ok to go ahead and put it all back together?

 

How can i be sure the cankshaft is in the correct position before i refit the head. I don't want to get it wrong by one tooth then have to strip it all to change it again!

 

Craig

[welshpug 1,657]

best to whip the liners out and replace the seals.

 

should still be able to pin the crank in place.

[c_r_thomson 0]

Thanks Welshpug,

 

I like how easily you say "whip the liners out"

 

I'm about to delve into an area never before ventured for me. The bottom half of the engine

 

I'm a bit nervous actually........

[Tom Fenton 1,541]

I'd measure the liners relative to the block. If they are equal then the chances are they haven't moved.

[Rob Thomson 6]

I've only ever taken a couple of these engines completely apart (i.e. including liner removal), but those behaved rather differently. The first (out of a BX16V) had very tightly fitting liners. There was no way they'd move at all by hand, I had to use a block of wood and a hammer to tap them out. And tapping is an understatement.

 

The other (a Mi16 of similar age) proved much easier to remove the liners from, the method that worked best seemed to be rocking them by hand from above to loosen. BUT, they still took a lot of force to move and when they first moved they moved a lot.

 

Based on that very limited experience I'd suggest that if there isn't any obvious movement then you probably haven't distrurbed the seals.

 

But I don't really know what I'm talking about and you should only think of the above as food for thought!

[c_r_thomson 0]

It's one of those Ballsy calls eh!

 

1. Risk it and pop it all back in and keep fingers crossed.

 

2. Just stop being a chicken and get it done!

 

I'm going to opt for option 2 i think. I would be a very unhappy bunny if i put it all back together and found water in the oil

 

As with the Crankshaft..... Just line it up as per Haynes joke book and turn over by hand many times to make sure?

[matty_gti 20]

Its a bit of a ball ache but go with option 2, whack them out, and i mean whack (well I allways have done, bloody things never want to come out) and just replace the seals.

 

When refitting just follow the haynes instructions then with the head back on remove the cam, take out the spark plugs (so pistons don't hit the valves) and rotate the crank so it lines up with the timing holes and go from there...That way peace of mind and when its done, its done

[eob 7]

I would be willing to bet a sum of money, my friend, that those liners haven't move a millimetre. If the engine has been running up until now then chances are the the pistons are moving freely in the liners.

 

Think of it has trying to pick up a bowling ball when your hand is covered in margarine. Not gonna happen.

[matty_gti 20]

lol, Even so, is it worth the risk?.

[c_r_thomson 0]

"Think of it has trying to pick up a bowling ball when your hand is covered in margarine. Not gonna happen."

 

Great way to put it

It's the threat of spending hours refitting just to find it needs to come out again. I went back to the garage and turned the engine over by hand a few times to see what happened. (Figured it was worth it if i was going to have to change the seals anyway!) The pistons move freely up and down the liners and the appear rock solid, no signs of movement whatsoever.

 

[welshpug 1,657]

but for what is such a cheap part it would be rather gutting if it were to leak once you got it all back together...

 

I'd drop QEP a call for a set myself.

[eob 7]

The thing is, though, that liners, once they in and they haven't moved (and it's pretty clear these 'uns haven't from the OP) then they're water tight. However, it's pretty common for freshly fitted liners with fresh seals to leak no matter how carefully you install them. I've heard of people in various threads here having to pour silicon etc in the bottom of the block to seal them tight when they're freshly fitted, whereas old liners never seem to budge.

[pip470 61]

Would it not be an option to take the sump of and fill the block with water over night, blocking the holes wher water come out? maybe on an engine stand?

[DamirGTI 342]

On each engine which i've dismantled in the past i had to bang out the liners with the wooden block from underneath , and with a bit heavy hammer .. if it's an old engine with high mileage i doubt that they've moved at all , you can see that by amount of scale sediment around the cooling galleries inside the block which forms around the bottom of the liners and kinda "weld" them to the block ! ..

On the other hand , if it was rebuilt with new liners/seals some time in the past few months or few years ago , then they could move a bit but also me thinks that they wont leak if you identify the moved one and press him back down the block (if the seal is still fairly new then the head clamping force will press the liner back down to form a water tight seal )..

 

First throughly check protrusion of the each liner with feeler blades and a flat ruler , then as recommended try leak test - buy some modeling plasticine (or something similar..) and block the water pump orifice on the side of the block and pour water inside the block up to the top of the liners ... leave it over night and next day check if the water is at the same level as it was day before .. or you could even whip off the sump and place a piece of cardboard underneath the engine so that you can see if there will be any splashes on the cardboard ..

 

Rgs !

Damir

Edited July 2, 2008 by DamirGTI

[RonnieG 0]

My twopence worth - On a 10+ year old engine the chances of the liners moving with just the pistons going up and down is pretty unlikely. I've always had to use wood and a fair 'hit' to dislodge them in the past.

 

If the seals have not been leaking up to now I would say you are far more likely to cause a leak by disturbing it all just to replace the seals than just leaving them undisturbed and rebuilding as is.

[ifcho 0]

On the last engine I disassembled one of the liners did not want to move at all...Finally after many hits with the hammer, it came out in pieces

[c_r_thomson 0]

On the last engine I disassembled one of the liners did not want to move at all...Finally after many hits with the hammer, it came out in pieces

 

Don't like the sound of that Ifcho!!!

 

It's the original 1991 engine on 80k The liners feel solid, I'm gonna try the filling block with water thing and see how that goes.

[Cameron 16]

I've never had a problem with liners moving on an old engine, as people have said they get pretty stuck after a few years! The thing is it isn't a case of 'just whip the liners out, replace seals, bish bash bosh, job done' as to get the liners out you need to completely strip the engine! The crank needs to come out to get to the bottom of the liners and that means engine out. Just stick the head back on and 99.9999% you'll be fine.

If you really want to be sure, put it together then fill with water (no oil) and leave it overnight, then take the sump plug out. When nothing happens, breathe sigh of relief, fill with oil, drive.

[ALEX 98 1 Cars]

Whip em out, It's easy as pie!

The hardest bit is undoing all those sump fixings. (adapt an battery drill with a 1/4" 11mm socket and extension bar)

Once the sump is off, unbolt the pump and unhook it from the chain. Mark the 4 bearing caps with a centre punch, I did 1 dot for cap one 2 dots for cap 2 etc. or use a paint to mark them before removing (Also note the bearing locating tabs on the cap and con rods go together) so you don't put them back on the wrong way round. Keep the bearings in the caps, unless they look worn, then replace them!

Drift up the liners & piston assembly from the underside using something soft like a piece of wood or plastic. You can get to the front and back underside edge of the liner with the crank in position, have a mate pull,wiggle on them too while you're under the car. Mark the front of each liner as it's common to refit the liners 180° to get more life out of them if you want. Then take the liners & piston assembly to an engineering shop for new rings and honing, unless you want to do it yourself, This is also quite easy but, tools are required. (ring clamp & honing drill)

Refit the liners with the pistons in them with new Liner seals. see Easy!

 

You can also check for liner protrusion using a steel ruler and feeler blades with the liners back in the block without seals. The tolerance is in the Haynes for this.

 

Edit, remember the big end bearings are angle tightend, I improvise with this using the corners on the nuts as 60° when I can't find my Angle tool.

Edited July 3, 2008 by ALEX

[ALEX 98 1 Cars]

If you fancy making a minter of it, price up some new liners and piston sets, I think about £250, You have to reuse your old con rods though.

[lagonda 42]

Just to add my twopennorth, the liners in mine took a few careful taps & much rocking before they eventually freed. Incidentally, there's no need to remove the crank BUT make sure you cover it as completely as possible to stop any crud falling onto it.

You could also factor into your decision if other benefits are worthwhile .... if there's a lot of crud/silt built up in the water passages, then it's worth removing the bores, as that will surely lead to overheating etc in future. Mine was peculiarly clean in that respect so don't assume there will be silt there. Obviously also if the bores are significantly worn.

Removing the bores is easy, replacing them takes time. You'll need to ensure the seating areas in the block are surgically clean, likewise bases of cylinder bores. Then ensuring your protrusion heights above the block is a pig of a job.

If you do the water in the block leakage check, add antifreeze! Sounds daft but antifreeze has a leak-seeking property.

Good luck

[Pugnut 9 1 Cars]

sit a steel rule on its edge along the top of the 4 liners. if they are all sitting pretty then it'll be fine

[ablister 31]

they'll be fine...

[pugman211 0]

i personally think they will be fine, my deciding factors would be, water test, condition of the bores, protusion test.

[maxi 36 1 Cars]

Your completely wasting your time, they will be fine. Bash the head back on and go and enjoy the car!

 

Maxi