[Spider.S3]

I hope the mods dont mind me putting this post in the "General" area.
but i hope more bods will read it and help.

I just picked up a 1962cc twincam engine for £35(for parts). the guy i got it off said it was seized. i put some oil down the plug holes and left it for 2 or so hours. i then put my big bar on the crank nut and it moved. the crank will turn all the way round freely, the pistons move up and down ok and the cams move ok to. the only thing is, every so often it feels like its seizing. but move the crank back 90deg and it moves forward again with no problem.
has anyone come across is before, or have any idears what could be coursing this.

Martin

edit..

just a thought. do the valves ever get stuck open ?

 

[harryf]

Whatever happens you'll need to strip it down. Start that and you're bound to find the problem.

 

[Paulus]

Harry is of course right but a liitle more info may be of use.

If you continue to turn where does it stop?

i.e. No1 cyl @ tdc? (or wherever)

when the camchain gets to a certain point?

Crank at a certain point?

Might be that we can put forward a diagnoses with more info!

Paulus

 

[Spider.S3]

what i am going to do is remove the head. but cant see a split link in the timing chain ?. is there one, or how do they come apart.

 

[Paulus]

There IS a split link (unless my brain has failed me completely!) as I can remember laying the camchain out each side of the head when doing tappets.

Do those checks first as I suggested though and we might save you some tears.

P

 

[Spider.S3]

ok the head is off, the hones/bores look good.
when i turn the crank it seem to seize (not all the time) when its at T/D/C OR B/D/C. but if i turn it back 90deg. it will move freely again.
it's like it does it 1 in 5 times.

I think tomorrow i will remove the sump.

 

[Paulus]

OK. As the head is off we can now eliminate all valve gear, cam chain. etc.

That leaves things like something laying in the sump (unlikely but you will find out tomorrow!), or auxilliary bits such as oil pump or distributer drive.

Main or big-end bearing shell or thrust bearing rotating is a possibility worth checking.

On relection I like that last one as it might explain the TDC/BDC anomally.

I am now wondering why it was up for sale!

Hope you find it,

Paulus

 

[AlfaLincs]

dear oh dear..you see all these new type Alfa owners with cam belt driven cars have obviously never heard of "The Split Link Club".

This is a self selecting group of Alfa owners who have found and extracted the split link....only to have it fall down into the sump

Good luck with the motor

AlfaLincs

 

[VeloceMitch]

......Or those that have peered down into a perfectly good engine, to find an outer link section completely missing from the bottom Cam chain, leaving it dangerously liable to part, thats when a simple service turns into a major rebuild

Shouldn't even be a split link on the bottom chain, but there was on mine.

Can't help with why your engine seems sticky though, maybe its a big end bearing problem, but I believe on the whole the bottom end of these engines is pretty bullet proof.

 

[AforA]

on the whole the bottom end of these engines is pretty bullet proof.

YOU GO TOUCH SOME WOOD!!!!!!! NOW!!!

And, for 1600 owners, please do not even think of beliving the above comment, as believe me, they are not!

 

[Spider.S3]

well i found out what is wrong. the big end bearing on number 1
is well F***ed. one haft of the bearing is broken in 2.

 

[Paulus]

Ah well, could be worse!

A quick crank regrind a set of shells and if you really want to go for it get the conrods examined by someone-with-a-machine!

All very do-able. probably the worst part would have been taking the lump out of the car!

Good luck

Paulus