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Discussion Starter #1
I have a very slight suspscion (sp?) that my cam timing might be out. I often feel im not getting the full 190 gee gees
1. Has anyone run a performance test using AlfaDiag? ie 0-60 800m etc so that I can compare.
2. Presumably to check timing I would need to take of cambelt covers, spark plug out get TDC on No1 and then check with cam locks?
I assume there is a timing mark on the crankshaft pulley?
I guess since the cam pulleys are friction fit on a taper they could be a fraction out?
A whole tooth ie belt slippage, would put the timing 9 degs out which I suspect would be noticable?
Presumably to adjsut the timing I would not need to loosen crank pulley which I believe can be a bit of an arse?
 

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1 No
2 Not the cambelt covers ,Just the 2 rocker covers and sparkplugs.Find TDC on compression stroke in NO1 cylinder and check camlocks fit.

No mark on crankshaft pulley hence need for TDC in No1 .

Yes on taper so it is possible.
Dont know about tooth out but above check will soon tell if it is..
Correct on both counts.......No ned to loosen crank pulley It certainly is

Pomeo.
 

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If you think you've slipped a notch, it must be a very bad idea to try and do performance tests :(
 

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A tooth would be noticeable if it happened all at once. I'm not too familiar with V6 but might expect valve-piston contact if it was 1 tooth out. Help Anyone!! Can't even remember if the your 2.5 has variable inlet timing?? If so the problem may lie here.
Have you any particular reason to point the finger at valve timing? Worth doing a diagnostic check before going too deep.
 

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Discussion Starter #6
I'm sure its not slipped a whole tooth - it runs/idles/pulls smoothly.
I'm wary of the Alfa dealer grease monkies who "rebuilt" (should be ripped off) my top end after belt/tensioner let go. The whole belt/tensioner had to be replaced less than 8 months later after I noticed the tensioner starting to fall apart. They never really seem to know what they are doing and I suspect their tolerances for assembly probably aren't great. That piston only has to be a couple of mm off TDC when timing up and its out of sync. Remember that at TDC the piston only moves a little way for quite a change in the arc of camshaft and crankshaft. It must be very easy to nudge something while you are trying to put tension on tensioner/belt and tighten up all the pulleys.
Sparkplugs due for change soon, so I'll check out timing then, while i've got everything off (another thing they didn't know how to do or negleted at the 60K service)
 

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Yes, quite, at TDC the piston is instantaneously stationary, so a dial gauge is needed. Having said that I did mine with a rod in the plughole! You're always left thinking " I could have just wrung another 1/10th HP out of it if only I'd.."
having read quite a few posts on this site I'm becoming convinced that I've done 2 right things. One is avoiding AR franchises and the other is avoiding 'genuine' spare parts, they're surely the same ones that failed prematurely the first time? I've so far had no problem with the bits I've fitted from motor factors. Touch Wood.
 

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If the engine is running smooth and revving to the cut-out then I would leave well alone.
I've had exactly the same niggling feeling since changing the cam belt myself. You'll be shocked to hear that I didn't use cam locks or any special tools :tut: .
There is mark on the crank pulley for TDC and there are marks on the rear of the cams. I established TDC by poking a stick down No1 plug hole and watching the rise and fall.
Removal of the crank pulley is not easy - there's no room for long bars and there's no room to swing a hammer. I ended up using a pneumatic impact wrench to loosen the nut.
To get the timing covers off the power steering reservoir has to be drained and removed and one of the pipes onto the pump need to be disconnected :eek: .
To loosed and tighten the nut on the cam pulleys you need a special tool to prevent pulley rotation - the pulley to cam joint is indeed a taper and separation is difficult.
When I did my belt I set up the engine at TDC and marked the cam positions. When I put on the new belt I found that the cams were ever so very slightly out of alignment. The RH exhaust cam was perhaps 1/4 tooth out he others not so much. however because of the cam/pulley taper joint etc I carried on.
After 5000 miles the niggles got the better of me and I borrowed cam locks, TDC indicator and pulley anti-torque tool and set about correcting the cam errors.
I was somewhat nonplussed to find that to use the anti-torque tool and to separate the pulley on the RH exhaust cam the engine needs to be lifted clear of the engine bay :wow:
After much deliberation I decided to give up and live with the errors.
Obviously it's psychological but I think the engine is running better since ;) .
 
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