Remembering why I
dislike working on
AO Silver Member
Join Date: Sep 2001
Re: 1995 narrowbody 155 2.5 v6
Sorry to say it...but you'll almost certainly find that the exhaust lobes and followers are FUBAR. They wear badly and no amount of adjusting will work for long, plus the obvious hit on perfomance. My '96 V6 rattles like a bag of spanners now. I put some different cams & followers in last year, but they weren't new and only marginally better than what I took out. Was pretty quiet for a few K miles but it didn't last, and the only real cure is new cams and followers. I've just bought a set of C&B cams & new followers for a 3l 12V 164 motor I'm rebuilding for this very reason. I had 8 cams - all shot. Not a single exhaust lobe or follower worth using (not that I'd use old followers on a new cam anyway).
Funny enough, the Alfa 75 crowd seem to acknowledge this problem (basically the same engine) and regard cams & followers almost as consumables, but I have trouble getting anyone else to admit it for some reason.
As for a sequence...well, you don't really need one - just get the cam lobe exactly opposite the follower and measure the gap. Just make sure you don't try and turn the engine backwards - it can damage the timing belt tensioner. I can't remember the figure now...the book specifies the clearance at the cam but since the exhaust is driven by a rocker, I find it more accurate to set them at the valve, but you have to multiply the spec by the rocker ratio (hence my comment I can't remember the figures at the moment!)
FWIW, 3l figures are;
inlet (at cam) .475 - .500mm,
exhaust (at cam) .225 - .250mm
Pretty sure the 2.5 is the same but I can check if you like.