Seized engine

Phil Robson

Phil Robson

Well-Known Member
My 2000 engine has not turned for 30 years & is somewhat seized.

I've removed the sump & undone the big ends which has enabled me to drift pistons 1 - 3 reasonably easily up the bores a little. No. 4 though is much tighter. I've had diesel in the bores for several weeks & am trying to turn the engine from the pulley end with a big lever attached with bolts to the pulley.

Would I be better trying turning from the other end after removing the clutch? I was going to remove the head but didn't want to upset the timing as I can't lock the cam sprocket in position.

Incidentally, I don't know the engine's history, but the main bearing shells are as new so I'm wanting to get the thing turning without necessarily stripping it down & fully rebuilding it - at least not when it could be OK. (I have a life to lead aswell! :LOL: )
 
I can't see it makes much difference which end of the crank you turn .Looks like No 4 piston is rusted to the bore with chances of the rings breaking .Have you got the spark plugs out ? can you undo No 4 big end and drift the piston up the bore with a lump of wood and a hammer

Have you tried filling the bores with diesel with the engine inveryted so the diesel gets to the bottom of the piston ?

Otherwise it's off with it's head
 
You do have to be carefull freeing pistons seized in the bore by using the methods described, although you have little real choice, but I did the same thing on a 1940's Chevy truck with the same problem, and when the pistons finally came out, one had a tiny hairline crack underneath where the pin goes through. If we'd missed that, the the piston would have cracked and broken once it was running again. As it was, with a s/h piston it now runs lovely! 8)
 
Mmm, looks like I've got little choice!

Will I mess up the timing as I'm not able to lock the cam with the key provided at the front? :?
 
The timing thing is kind of irrelevant if you're taking the head off. Once the head is off you can lock the cam in the right position, then if the pistons free off ok, lock the crank in the right position and put it all back together.
 
Thanks for the advice.

The head is now off & I've disconnected the big ends. Pistons 1 to 3 are fine & I've got no.4 moving although it is still stiff compared to the others. I will keep working it up & down with liberal squirts of WD40 & diesel over the next few days.

Incidentally, there is NO sign of damage to any of the bores (even no.4). The big end bearings are slightly bronzed in places so I suppose I'd better change them. The crank at the big ends looks extremely good aswell. Would you recommend changing the main bearings & crank oil seals whilst I'm on?

I'm not really wanting to dismantle anything else on this occasion, although I'll put new side plates on. If it was necessary to do the head, I could do it in car at a later date. :)
 
You would have to think that after 30 years of storage that the front and rear crank seals would have hardened up a bit. Far easier to replace them now than to have to do it when the engine is back in and running. For the sake of the cost of the bearings, you may as well do the shells now, the bores should be fine with a hone and new rings.
 
Thank you all for your advice. I've now got the engine free. The head is off & the big ends have been disconnected:

65ydm0.jpg


I am surprised at the good condition of the bores & bearings (which will be replaced) given that the engine has done almost 100,000 miles. Also, I have never been able to find the engine number - it's certainly not in either place it should be. However, tonight I discovered the following plate under some crud on the lower LHS of the block:

maghud.jpg


There has been a thread on here recently about early gearboxes being rebuilt by Rover (mine is one), but I hadn't heard of engines being done. As my car has been stationary for 31 years it could have been rebuilt say 30,000 or 40,000 into it's life which could explain its condition. Does anyone have any ideas? :?
 
With 100k miles on it I would recommend taking the block to an engine shop to be measured before buying the bits. I wasted money when I rebuilt my engine buying a new crank and shells, the old one was shot when no2 big end went on the motorway. When I put the crank in it locked up when the mains were torqued. Turned out my block was very slightly twisted and needed a line bore. I was lucky to find an unused reconditioned short engine from a p6roc member as a replacement.
 
Please don't laugh :LOL: but presumably '010' marked on the main & big end bearings on my 2000's engine means that these are +10 thou oversize bearings....

Despite having P6's for 21 years I've never taken an engine fully apart before, so I'm still on the steep bit of the learning curve :D
 
Phil Robson said:
Please don't laugh :LOL: but presumably '010' marked on the main & big end bearings on my 2000's engine means that these are +10 thou oversize bearings....
Click to expand...

Yes, to fit a 10thou undersize crank. (Look at the serial number on that recon plate and the last 2 numbers look like "/10" for 10 thou undersize big ends and mains at a guess.
 
Thanks Harvey,

As the journals (& bearings) are all good, I can presumably fit new +10 bearings & put it back together. I'll put new crank oil seals in & new piston rings on after honing the bores. That should do whilst the engine is out (gearbox will be looked at & clutch obviously changed). :)

I've no way of telling how many miles the car did after the engine was rebuilt - probably not that many by the looks of it! Incidentally, when I emptied the gearbox, the oil was like new.
 
It seemed to have some rust in the cylinder, although the bore is not marked now. The others were a bit tight also, but they haven't turned for 30 years!
 
Hi JVY,

Today it was the rebuild of the clutch master cylinder which I'll hopefully fit tomorrow night. Not the engine, I know, but it helps me keep sane!

The engine is part dismantled & cleaned. I've got some new main bearings at +10, & will get some new big end bearings & piston rings soon & the relevant gasket sets. The pistons are not out yet, but I've turned the engine several times now.

I did have some replacement side plates but can't find them (until I buy some new ones, that is! :D
 
Phil Robson said:
I did have some replacement side plates but can't find them (until I buy some new ones, that is! :D
Click to expand...

It's been a long time since I've done anything on the engine, but I have got replacement plates now, & have found the others!

harveyp6 said:
Phil Robson said:
Please don't laugh :LOL: but presumably '010' marked on the main & big end bearings on my 2000's engine means that these are +10 thou oversize bearings....
Click to expand...

Yes, to fit a 10thou undersize crank. (Look at the serial number on that recon plate and the last 2 numbers look like "/10" for 10 thou undersize big ends and mains at a guess.
Click to expand...

Back to problems though. I've got new '010' marked main bearings, but have now removed a piston to find that the journal measures exactly standard :? . This is with electronic vernier calipers. The pistons seem to be standard as well!

Presumably I'll have to get it professionally measured to be safe?
 
You should be able to trust your own measurements as much as trusting someone elses. Are there any markings on the shells that came out?
 
Possibly your block has been line bored and your crank is still standard, this would mean that the shells would be +10 wider to fit in the bearing caps.

Graeme
 
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