Cam Timing

[Pat's91]

Got the head on my 91 Spider reinstalled, tensioned the chain, rotated it several revs by hand, verified TDC with dial gauge and now checking the cam timing. The exhaust cam mark is the width of the timing mark before the ref mark (the marks are just touching). According to an article by Herb Bridge on finding TDC, one mark width is one degree of cam rotation and since the sprocket vernier adjustment is 1 1/2 degrees this is about as close as I'm going to get.

The intake side, however, is 3.5mm past the ref mark (3 1/2 degrees advanced?). My question is how will affect the engine in regards to valve interferance, idle quality and performance?

Am I right thinking this increases overlap and therefore will cause more unburnt fuel to leave the engine? I reviewed previous posts on the adjustment and don't think I can get the tools neccessary to adjust the cam before this babby ships to Kansas City next week (it's crunch time!).

Greatly appreciate your help! Pat

[Pat's91]

A very knowledgable Alfist suggested checking to see if the intake cam was off by one tooth - it was ! Now both cams are pretty close - just off by the width of the timimg marks, I can gladly live with that! I also messed up by putting antiseeze on the head bolt threads instead of oil - he said it changes the friction enough to result in effectively higher torques so I removed, cleaned, oiled and reassembled.

Onward with the assembly. This learning curve sure is steep, but fun.

Pat