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[Vitaliy]

Hi guys
Besides my fathers problems with his omega snapping a cambelt I have some other issues on MY omega.
I have got it this monday with snapped cambelt as well. Guy broke down an hour before I called him asking to buy it ( it was advertised as all up and running). He was so angry with it that he made me an offer I couldn't refuse. Difference is its x20xe ( or x20xev cant remember).

Well after removing the head it has 6 valves bent and something weirder - 2 inlet valves on different cylinders have their seats further in the head. I was offered a complete head from running engine for peanuts so i got it. Now main question is: as it was removed ready for collection cam bearings caps/shells ( I am not native English speaker so please forgive me if I am using wrong term) are not ordered correctly in my view. guy who removed it insist its in correct way as they were in the head bolted. Lets just say i dont trust this chap.

I have previously rebuild a few x20xev heads and i was the first guy opening the engine on 2 of them. All caps are numbered so is the cylinder head  places. Should i put them in their rightful places or as they were in the head then I picked it up? Usually I wouldn't even ask this question and just put them in the right numerical order, but surprise surprise - caps on my old cylinder head were totally mixed up as well and it was running ( I am not the first one opening this engine that is for sure)  .

Any thoughts and suggestions will be much appreciated.

[Andy H]

If you lift out all the cam followers is there enough space to turn the cam without it striking the valves?

I would be tempted to fit the caps in the correct order (without followers) to check that the cam turns freely.

My guess is that the cam will be difficult to turn with the caps in the order they are now.

I also suspect that having the caps in the wrong order may have contributed to your cambelt failing 

[Vitaliy]

Am..
Maybe I dont understand something, but what followers are we talking about in 2.0 16v DOCH ecotec engine???

Cams operate hydraulic lifters (tappets) that have valves under them. Do you mean these tappets than?

[RobG]

Am..
Maybe I dont understand something, but what followers are we talking about in 2.0 16v DOCH ecotec engine???

Cams operate hydraulic lifters (tappets) that have valves under them. Do you mean these tappets than?

AKA followers

[Kevin Wood]

I would trust the numbering on the caps and, as said, assemble without tappets and check for any tight spots during rotation. Check the caps for obvious wear too, if they may have previously assembled the wrong way round.

Also, offer up each cap without the cam and feel for a step in the bore where the cap meets the head. This should line up perfectly.

[2woody]

Good advice from Kevin - as ever.

when trying the caps, do just one at once, so that's.....

cam out
followers out
each bearing cap in place and torqued VERY carefully
feel for a step
bearing caps off again
cam in
tighten (carefully) the first cap
check if the cam rotaes easily
remove the first cap
tighten (carefully) the second cap

and continue until all five are done

[Andy H]

& make sure the bearing surfaces are clean and well lubricated.......

[Vitaliy]

Thank you all for your help. Tomorrow cylinder head goes to be skimmed, valves lapped in and stem seals changed. Here there is a specialist company that will do it in 2-3 hours. Great people. When I come back with it tomorrow ( assuming they dont have 20 cylinder heads to do) I will do just that.

Thanks again.

Have a nice evening.

[2woody]

maybe do the cam bearing thng first, just in case they don't match the cylinder head at all ?