Timing belt one tooth off!

[green57]

Guys finally got the new head on the SVO and its up and running again and has passed inspection.

Only having one problem, seems I can't get the timing belt on correctly again for the second time, by second time I mean I remember having this same problem once before.

I have lined up the timing marks for the crank and cam (double checked using the string method) but when I take the slack out of the timing belt and try and place it on to the cam the teeth don't line up. I get tooth to tooth contact.

I remember I had the same problem two belts ago. I got it running but it was sluggish but still ran. When I changed that belt out for the next one I put on, I did the same procedure but this belt went on with the proper tooth spacing. It was like a new car, lots of power and fun to drive again.

I would put that old belt on again but its about six years old now. I got it form Autozone and it was made in Italy. My new one is one my wife got at Carquest when she was TDY in the states, it's a Gates and made in the U.S.A.

Are all belts not created equal?

I feel like just ordering another belt from Autozone, but I don't know if I'll get another good Italian one or something from china.

Any tips on getting things to line up, I'm sorta stumped and feeling like a chump.

Thanks for any help.

G57

[Under Pressure]

I had the same problem. I had part of the plastic pointer bolt down that was cracked and that allowed the pointer to be off enough to create the alignment issue. I fixed that and was able to get correct alignment.

[Meotchh]

Have you tried checking the cam timing using the e-bar method?
http://store.esslingeracing.com/cart/ebar-details.aspx

[Mike S]

Timing belt dimension should be standardized just like roller chain pitch, but there is a difference between metric and standard roller chains. They have the same pitch in inches, but that is where the similarity ends. Use google to find a pitch chart for timing belts and compare the new with old using calipers.

[MikeFleming]

Belts stretch with time and use (heat cycles??). Belt stretch can make aligning hte teeth difficult - that usually means the belt needs to be replaced.

Another factor is how much the block and head have been cut as it makes the center line between the crank and cam sprockets closer. Which means the cam sprocket will be retarded more.

Outside of missing/worn keys, worn keyway slots in sprockets and after-market sprockets that's about it for cam/belt misalignment.

[green57]

The head has been surfaced but the block has not been touched. The back side of the belt cover is broken, so that might be a factor. I'll give it another shot and mark the belt and cam sprocket and adjust left or right one tooth 'til it runs like it should. A little extra work no doubt, but I guess thats what three day weekends are for, and it'll keep me from lookin' at to much porn.

Thanks for the input.

G57