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My engine (S2, 2 litre)has done 25k since a major (complete rebuild) and is starting to sound a bit tappety when hot , presumably thats not an unreasonable mileage to expect this?. I've only adjusted A series tappets before so this shim business looks a bit of a pain, is there a definitive guide (there seem to be several different opinions on the best way to do it) to the procedure or would it be best to leave it to my (extremely good) mechanic, I am mechanically competent but really dont want to mess this up.
Thanks
 

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it is a job any competent mechanic (ie. You:)) can do - but it takes a bit of time and patience.

Before you start, you sure the 'clackety clack clack' is not from the timing chain? maybe that just needs adjusting?

valve gap adjustment-
apart from the usual tools, you'll need a good Micrometer, and that costs a little, a good torque wrench, a new cam cover gasket (plus washers and half moon rubbers to be really correct), a good feeler gauge, you'll probably need to buy some shims, and a piece of paper.

Cold engine
Remove spark plugs (makes turning engine easier)
Remove cam cover and gasket
Check torque of cam caps are to spec (important, if the caps are somehow loose, your readings will be all over the place!)
measure valve gaps on each cyl. with feeler gauge, noting these down on a piece of paper....you need to turn engine manually to get the individual cam lobes facing directly up over each tappet (see link below for diagram)..........

If you now find they are out of spec:

Set valve timing (TDC on compression, two front cam lobes facing out and notches on front cam-caps line up with marks on cams.....the removable chain link should be now up top between both cam cogs.
Release cam chain tensioner bolt, lever tensioner back and lock it in place
split the chain (don't drop the link into the engine, stuff big rags under it!), hang the chain up out of the way, keep it taut and don't let that fall in either!... and remove the cams....keep all cam caps in order and they have to go back in the same direction [there is an alternative method of doing this w/o breaking the chain, outlined in Pat Braden's alfa bible]
Remove the tappet cups with a suction cup or magnet (keep these in their exact order, they need to go back where they came from as well!)
Under each tappet is a shim, measure each shim with the micrometer and note this on the piece of paper where you noted the original corresponding valve gaps.

Now comes basic maths: you need to work out which shim (ie. thinner or fatter) is needed to put the valve gaps back to factory specs.

Like this:
Thread Page - Alfa Romeo Owners Club USA

then put everything back, cam lobes facing out, marks aligned, use correct torque on valve caps, reset tensioner, then turn engine again manually and measure your results on each valve.


It has been years since I did this, so anything I missed, others will correct, mehopes:)
 

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Discussion Starter #3
Thanks S4 - you are a fount of knowledge, I'll check the cam chain as well but am pretty sure its the tappets
 

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Thanks Rich - I'll probably leave it until winter but will let you know, - let me know when you want to do the exhaust
 

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Saturday is a possibility and maybe sunday morning but if weathers good I'm off for a drive, just checked the forcast and its not looking hopeful for a while.....
 

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Raking over old posts for information! Can anyone advise correct gaps for a SII 1750 in standard tune please? Having replaced water pump, tensioned cam chain, checked alternator, listened to to the engine with a screw driver against my ear, it's still a bit noisier than I am comfortable with...or this is just what Alfa engines sound like? Also torque setting for the cam caps pls. Many thanks.
 

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couple of charts ought to help:

not every run o' the mill torque wrench will read under 20 ft/lbs, so you might have to borrow one!

remember when first checking valve clearances, check the cam caps are correctly torqued first.
superb. Many thanks.
 
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