1980 308 GTSi 2v Cam Belt Change

Need some advice. I'm a decent mechanic have a couple race cars and a few collector cars. I've been studying up for a year or so on how to do a cam belt change on my 1980 308 GTSi, using a few different resources including birdman's procedure and cam locks. 100% sure I did everything right in terms of locking cams and flywheel at TDC, went way overboard in marking the belts and each pulley in several places, rebuilt the tensioners with new bearings and put new belts on. Everything seemed perfect up until this point.

Here is where things went bad today and heartbreak is setting in. Removed cam locks and unlocked flywheel. Kept the tension screws loose so the spring was constantly pushing against the belt. Rotated the engine 2 full revolutions keeping and eye on the tensioners to see where max tension was needed and prepared to lock down tensioners. But, at that point I checked my marks on the belts and pulleys and they were way off. Turned engine clockwise with tensioner springs pushing against the belt.

What could possibly have caused this? Is it possible that I may have bent valves by turning the engine over by hand and with it seeming to get out of time?

If there is anyone that would be willing to chat and talk me off the ledge I would appreciate it. I'm in the Chicago area and there are a few Indi ferrari shops I will reach out to next week, but wanted to ask the forum if I'm missing something?

 

If that’s all it is, I’m going to buy you a gift. Seriously? I was trying to do that math, but didn’t want to keep turning.

I was thinking that it seemed logical that my marks would line up every 2 rotations?

 

Smg2, you just dashed my hopes. Is it 4 or 16. I think I turned 3 times and stopped

 

Thank you all for the replies. I went back to check and TDC on the Flywheel lines up with TDC on the cam through the oil fill hole as I photographed before changing the belts.

for the life of me I can’t figure out if/when/if ever the marks on the belts would ever line up with the marked teeth on the pulleys again? I think it’s a math problem having something to do with the number of teeth on the belt and the number of teeth on the pulleys. Turned the engine by hand 20+ times and no dice. Teeth on belt belt never line up again with teeth on pulleys where I originally marked? Any thoughts?

You guys have been fantastic. Thanks for all of your comments.

 

Thank you all for the replies. I went back to check and TDC on the Flywheel lines up with TDC on the cam through the oil fill hole as I photographed before changing the belts.

for the life of me I can’t figure out if/when/if ever the marks on the belts would ever line up with the marked teeth on the pulleys again? I think it’s a math problem having something to do with the number of teeth on the belt and the number of teeth on the pulleys. Turned the engine by hand 20+ times and no dice. Teeth on belt belt never line up again with teeth on pulleys where I originally marked? Any thoughts?

You guys have been fantastic. Thanks for all of your comments.

 

I’m very intent on understanding when the belt would come back to the original marks. I’ll get back to with number of teeth on belt and pulleys.

 

Again guys, thanks for all of your time and thoughts. If I could do it all over again I would have paid more attention marking the cams. I think the reason birdmans procedure has you mark the belt is to just be sure the new belt goes on identical to the one that comes off. You still have to lock the cams and crank which I did. But by marking the belts, the crazy question came up of when will/how many rotations for belt marks and pulley teeth to come back to original position. I did many/20+ turns and never lined up. Crazy.., sorry for the math/engineering question.