Technical Misaligned cam and crank gears.

[W Bakker]

Well, as it says in the title, my crank and cam gears moved while the chain was off. I left my engine on the bench to continue working on it today. When I came back, my dad had messed with the gears trying to figure out what I was doing.
Very frustrating that this relatively simple job has gotten a lot more complex

I was hoping anybody has any advice on realigning the gears. It's a 650cc engine out of a 126.

 

[giardini]

I'll give a provisional answer in case you're twiddling your thumbs waiting for one: the crankshaft sprocket is marked with a line on its
periphery, and the camshaft sprocket similarly with a dot. These must be aligned, as in facing each other exactly. That's for a 500, I imagine
the 650 is the same.

 

[Goldnrust]

To add to the above, the sprocket only fits on the cam in one orientation. The bolt holes are subtly offset, so if all 4 go in then you've got it bolted to the cam in the right location.

 

[W Bakker]

Hey all, I got it all bolted up but I think I might have the cam 180 degrees out. I serviced my distributor and when I reinstalled it and set it to the base timing of 10 degrees before TDC nothing happened. The car just kept cranking away. Any ideas?

 

[Toshi 975]

You cannot have the cam 180 degrees out if you have lined up the marks as described above. However you can have the distributor 180 out. Easiest check is to swap the ht leads on the distributor cap.

 

[The Panda Nut]

Ended up in this position many years back. In that case the workshop book was incorrect. I went back to first principles and worked out when No1 was at TDCThen by watching when the distribiutor was pointing to No1 lead was able to do the same with the camshaft until the inlet valve was just closed. Then the marks were 108 degrees from the workshop book. I determined it was wrong and tightened it all up and it was correct. It really only takes a few minutes to line it all up. Will add that this was an 1296 Renault engine. The same actions should lead to correct alignment of the timing marks on an older style engine.

 

[bugsymike]

As a quick cheat on ignition timing with plugs out , turn engine by hand to what you think is no. 1 cylinder with your finger over the plug hole as you feel it coming up on compression by the air blowing past your finger, then watch the piston come up to just before the top of cylinder (hopefully some ignition timing marks should have aligned on pulley, then look at the rotor arm in distributor, it should be pointing to the corresponding plug lead in the cap for No.1 cylinder, then it should run apart from final adjustment.

 

[W Bakker]

Ended up in this position many years back. In that case the workshop book was incorrect. I went back to first principles and worked out when No1 was at TDCThen by watching when the distribiutor was pointing to No1 lead was able to do the same with the camshaft until the inlet valve was just closed. Then the marks were 108 degrees from the workshop book. I determined it was wrong and tightened it all up and it was correct. It really only takes a few minutes to line it all up. Will add that this was an 1296 Renault engine. The same actions should lead to correct alignment of the timing marks on an older style engine.

This did the trick! Thank you all for once again taking the time to help me out. Now onto the next challenge, hunting down the oil leak.

 

[W Bakker]

This did the trick! Thank you all for once again taking the time to help me out. Now onto the next challenge, hunting down the oil leak.

Oil leak has been found aswell. Turned out to be a crack in the crankshaft pulley!

 

[bugsymike]

Oil leak has been found aswell. Turned out to be a crack in the crankshaft pulley!

Unusual.