Cam Timing Dilemma

The cam seal holders with the scribe lines are fully floating on the orings, the stake marks on the gears only line up if someone took the time to set them up that way.

The stake mark on the back of the cam suggests there might be some misalignment. Set up a degree wheel and do the cam timing per the manual, that is the only way to be sure. None of the staked marks can be trusted to accurately set up the cams on the 355.

How many miles/years on those belts? Looks like a good deal of tooth wear on the belts.

 

Those marks have no reference to actual cam timing. They are staked at the factory during original assembly but very often to get correct cam timing during services you will need to move the pulley and often even turn pulleys 180 to get the cam timing to specifications. Do Not Use Marks to Set Cam Timing. Use a Degree Wheel and Dial Indicator.

 

I agree with winsock: The timing marks staked on the parts are just to get you in the ball park. To "set the cams" you need a dial indicator and a degree wheel (goinometer--what a great word).

 

How is that pronouced?

Goinometer (hard G like the word "going to the beach)

or

Goinmoter (the G being soft like "Jin" or "Gin and juice")

 

If any interest, the word is (fortunately) goniometer - a whole lot easier to pronounce (hard "g" Ace Master). It's the generic name for an instrument for measuring angles and, naturally, it has its origins in Greek - gonia = angle.

 

Who says we're a bunch of uneducated wrench monkeys? Real scholarly we are.

 

Might just be the photo but the finger on the cam sensor trigger wheel looks bent or ground down to me.

 

While the mechanic may not have done good work the marks have nothing to do with cam timing. Properly setting the cam timing involves adjusting the dowel position in the pully. The stake marks were only good for the first cam timing settup at the factory and cannot be relied upon again. It is very common to find the marks off once the cam timing is adjusted properly. Get a service manual and read the procedure.

 

+1

 

Thanks for taking the time to answering the question.
Interesting that after that short period of time the belt shows markings on the outside. Does belt streaching cause this? Whats the reason? Anyone know?

 

Based on the belt tooth wear shown in the first two photos (left side as viewed, one tooth to the left of the red line)... it surely brings the replacement to question. That stated, I have never worked on a 355 that saw 40 K Km in a year and a half.

It is this tooth wear that we have been working to reduce thus allowing more consistent cam timing over the life of the belt. There are those that say there is no such thing as "Belt Break In", I respectfully disagree as we have 7 yrs research into this to date that leads us to believe otherwise. We keep learning on each repeat service... one day I might be able to state something as fact and not theory.

The groove in the base of the belt tooth causes the tooth to splay outwards slightly when the tensioner tightens things up. It also allows a slight 'flex' of the belt in the area of the tooth. Really a very cleaver design that is well applied in this case.

 

I agree with Dave.

 

Why is it that metric people don't use the term Mega Meter but instead use Kilo Kilo Meter?