850 Head Removal and Replacement

**The Flying Moose** · Wednesday 6th July 2011, 22:22

Folks need some advice here. Im affraid my technical knowledge is lacking and my ability to undo nuts everymore improving.

Basically I am removing the head off a donor T5 engine to get skimmed and refurbed and placed onto my engine as the valve stem seals are shot.

I have removed the cambelt etc and began to remove the cam sprockets however after removing the last nut on both sides the drill bit I used to keep the cams in place didnt work and both have moved considerably from their original loaction.

My question is what impact will this have? Is it mainly important for the bottom end or am I likely to have ruined the top end too?

If they need to be in the correct place can they be re timed up with relative ease as this if applicable will obviously need doing prior to fitting to my engine.

Cheers

**Tomcat** · Wednesday 6th July 2011, 22:32

They'll be fine mate, that's just the cam timing, provided they're lined up again before you stick the cam belt on you shouldn't have any problems.

**The Flying Moose** · Wednesday 6th July 2011, 22:50

Originally Posted by Tomcat

They'll be fine mate, that's just the cam timing, provided they're lined up again before you stick the cam belt on you shouldn't have any problems.

Cheers TC. Obviously the sprockets are removed at the moment too. How do I go about re-aligning it all before fitting it onto my car then? Can it be done easily as im assuming there are no marks on the cams themselves as to where they should be seated and to which orientation.

**Jamest5r** · Wednesday 6th July 2011, 22:51

Tippex is a man's best friend

**The Flying Moose** · Wednesday 6th July 2011, 23:05

Originally Posted by jamest5r

Tippex is a man's best friend

Only problem is james they have moved after the cam sprockets were taken off. How do I know where they should have been in the first place?

**silverswedemachine** · Wednesday 6th July 2011, 23:19

You may as well put the cam wheels back on cos you dont need them off to take the head off, like some one said, mark them up 'In' and 'ex' for when you take the cams out/off... The cam wheels will have a 'clean spot' on them where the bolt was origianally placed so just as long as they go back in the same place, you should'nt have a problem timing it back up, combined with the other timing marks on the timing cover... The only other thing i have read is that getting the cam cover down (when its being re-built) cleanly/correctly is not straight forward, i think it involves some long threaded bars (x4) with a nut on it (i think its to do with the bolts are'nt long enough because the valve springs will need compressing by the cam) to start seating it and then you can start putting our bolts back in once its down far enough, also make sure it goes down evenly...

**The Flying Moose** · Wednesday 6th July 2011, 23:22

Originally Posted by silverswedemachine

You may as well put the cam wheels back on cos you dont need them off to take the head off, like some one said, mark them up 'In' and 'ex' for when you take the cams out/off... The cam wheels will have a 'clean spot' on them where the bolt was origianally placed so just as long as they go back in the same place, you should'nt have a problem timing it back up, combined with the other timing marks on the timing cover... The only other thing i have read is that getting the cam cover down (when its being re-built) cleanly/correctly is not straight forward, i think it involves some long threaded bars (x4) with a nut on it (i think its to do with the bolts are'nt long enough because the valve springs will need compressing by the cam) to start seating it and then you can start putting our bolts back in once its down far enough, also make sure it goes down evenly...

If thats the case ill put them back on luckily I marked them inlet and exhuast and put an arrow to top side. Only slight issue with the cover is that its damaged and unmarked so can only go by the official marking as per detailed in the haynes manual.

**silverswedemachine** · Wednesday 6th July 2011, 23:28

NOt sure what cover you are referring to when you say its damaged, but as long as your back plate, behind the timing belt, is ok, just line the volvo timing marks on the cam wheels with the notches in the back plate, its easy job on these...

**The Flying Moose** · Wednesday 6th July 2011, 23:35

I was reffering to the plastic rear cover. However I think I know what you mean.

The square cut out notches in the plastic and the engraved lines in the cam sprockets as below yes?

**silverswedemachine** · Wednesday 6th July 2011, 23:42

Yup, thats how it should be... Crank notch, its at the back nearer the block, is a little harder to see mind you...

**Alan M** · Thursday 7th July 2011, 07:28

You need to keep the crank in position at its mark. Then lock the cams in position in the upper cover with a suitable tool at the rear, homemade will do, after applying sealer to the upper cover. Make sure your cam journals/lobes are lubricated or you will cause an interferance problem well the cams will fail to rotate and be effectively locked because of no lubrication. The cams at the rear are slotted in a certain way that they go in in a certain position. Then pull the upper cover down with some other home made tools or the proper items onto the head. I would use new genuine lifters when re assembling as the engine will need another strip down the line to replace them if not. The assembly procedure in haynes is pretty well explanatory if you just re read it a few times and keep a methodical approach compared to removal. If you get stuck just PM me and I'll pass on my number for you to call.

**Wobbly Dave** · Thursday 7th July 2011, 09:07

seen some cheap tools on ebay for cam locking. Proper Volvo one was 175 quid!!

**andyb1375** · Thursday 7th July 2011, 18:56

Em..Dont panic i have the locking tools and I will fit the head and time it for you..You will need to remove the cam wheels as we will be starting with a bare head.

**deathrider311271** · Thursday 7th July 2011, 19:33

hey moose if u need a hand when doing that part i can bob down to help mate

simon

**The Flying Moose** · Thursday 7th July 2011, 23:05

Managed to get the head removed today, all sorted thanks chaps for the advice. A little dawning as I had never done anything on this scale before but afterwards you realise as with all things automotive its only nuts and bolts!