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325i m20 cylinder head refitting.
Posted: Mon Nov 12, 2007 7:30 pm
by diamondblacke28
im considering overhauling the cylinderhead on my 325i (1988 f)some time in the new year.
my only concern is after the head has been rebuilt and i come to refit to the block.
how to you time the head up to the bottom end.
i no the ecu sets the timing.
is there any marks that require linning up before the timing belt is fitted.
appreciate all replys
Re: 325i m20 cylinder head refitting.
Posted: Mon Nov 12, 2007 7:46 pm
by Nelly
Theres 2x timing marks to line up before you remove the head, one is located on the front face of the head - line this up with the groved tooth of the pully on the head, the second is on the back of the crank pully which lines up with it's relivant mark on the lower timing case cover - line them up using a 22mm socked on the big nut in the centre of the pully assembaly - if both don't line up first time you'll need to rotate the pully assembaly another 360 deg.
Once this is done you can remove the head knowing that when mated again it'll be 'in time'
Neil.
Re: 325i m20 cylinder head refitting.
Posted: Mon Nov 12, 2007 8:00 pm
by diamondblacke28
i plan to strip the head down and rebuild so would'nt that mess up any linning up i did before i removed the head
Re: 325i m20 cylinder head refitting.
Posted: Mon Nov 12, 2007 8:20 pm
by Nelly
Once you've done the timing marks and removed the head, take a picture of the underside of it ie; the valve alinements - once you've got it skimmed and rebuilt you can turn the cam shaft pully buy the torch bolt in the centre to acheive the original position.
It's some thing that's gonna frighten most E30 owners but once you've done it you'll wonder why you beat your self up about the "What if's" + the "But's"
Neil.
Re: 325i m20 cylinder head refitting.
Posted: Mon Nov 12, 2007 8:31 pm
by diamondblacke28
thanks alot for your advice nelly
Re: 325i m20 cylinder head refitting.
Posted: Mon Nov 12, 2007 8:36 pm
by Nelly
No problem fella - just don't let it frighten you, also watch out for that metal vertical breather pipe - spring loaded and can leave a nice mark on flesh
Neil.
Re: 325i m20 cylinder head refitting.
Posted: Tue Nov 13, 2007 9:25 am
by wrobstar21
I got done by that!!! Clean the block properly too as i made that mistake and will have to do it all over again i think!
Re: 325i m20 cylinder head refitting.
Posted: Tue Nov 13, 2007 4:58 pm
by daimlerman
Be worthwhile reading through the tech article with piccys that deals with cylinder head strip/rebuild.The M20 engine is a joy to work on,it comes apart in a logical way that is easy to understand.Once you have the radiator out of the way you will be able to see the marks on the bottom of the engine.
Re: 325i m20 cylinder head refitting.
Posted: Tue Nov 13, 2007 10:13 pm
by diamondblacke28
cheers
wrobstar21/daimlerman.
Re: 325i m20 cylinder head refitting.
Posted: Wed Nov 14, 2007 10:16 am
by Morat
You need to remove the radiator?
Bugger, that means bleeding it again

Re: 325i m20 cylinder head refitting.
Posted: Wed Nov 14, 2007 11:00 am
by mattG
Always turn the engine by hand/spanner on the crank bolt when reassembled, making sure the engine turns smoothley & freely with the spark plugs out a couple of revolutions. Never on the starter motor!