Leon Speed

The rotors were originally correct, now not anymore, they should point between the two casting marks on the inside of the gear.

The crank is in the correct position with the key at 1500 hours. However, the cams are 180 degrees off.

marine928

ok, just to be clear.. the white marks were made by me to mark the belt position when the cams were at 45 BTDC. Before that I had rotated the crank to align the cams at TDC. They were aligned with the "V" in the back plate and the slot in the cam sprocket.
So that we are on the same page, the white mark represents the cam position at 45 BTDC, I did not mark them with paint at TDC.

Thanks

Lon

Bill Ball

You are at 45 BTDC cylinder 6, one crank rotation away from 45 BTDC cylinder 1. Hence, the cam gears are off 180 degrees (before they moved). There is no particular reason you can't complete the timing belt job as is. You just need to be fairly sure you are on the right cam tooth (3 teeth before TDC mark, 180 degrees away) when you install the belt. After the belt is installed and at least partially tensioned, you can rotate the crank around one turn to 0 TDC cylinder 1 and check the situation. If off more than 1/2 of 1 tooth, loosen the tensioner and reposition the belt. Note - don't use bolt to rotate crank w/o the balancer, pulleys and washer/spacer installed. The bolt may bottom out and scrunch some threads.

marine928

Ok Bill, I will make the adjustment, it is just perplexing that I am off that much. It is not that difficult and with two pairs of eyes and two heads ( my assistant who is pretty smart) I don't know how it got so far out of position. Following Dwayne's write-up to the letter.
I will also position the rotors correctly between the two marks.

Thanks everyone for all the help!! I will put on my dunce cap...

Leon Speed

Right, you rotated to TDC first and saw the cam gears aligned with the backplate. Then you rotated the crank one more time to put it at 45 BTDC but since you rotated the crank only once you put it at 45 BTDC at cylinder nr. 6 as Bill says. Putting it at 45 BTDC at cylinder nr. 1 would have required two crank revolutions. Hence the 180 degrees of on the cam.

marine928

Oh.. the light bulb just went off..call me "grasshopper"

marine928

so, what do I need to correct this brain far*

fraggle

Sometimes I use a strap wrench to turn the gears when I need to.

marine928

Wow Frag, thats quite a set up on your 87..

marine928

Leon, looks like I will use the original "Red" marks from the previous PO's services as my 45 BTDC position and take a pick of the rotor position(s) and see how that looks.

marine928

I used the previous PO'S marks as a reference for 45 BTDC, put the rotors on correctly for reference. Does this alignment look correct? can I proceed with the service confident that the cams are at 45.

Thanks

Lon

Bill Ball

See the tooth valley where the wide notch is on the gear? Look on the back edge of the gear and you will see a tiny notch in the valley - that is the TDC timing mark. You should be at the 3rd valley before that. Driver side looks OK, but passenger side looks to be on the 4th valley over. I see the red mark on the passenger side is not on the valley but on the tooth crest. It may end up that way - in other words 1/2 tooth off. Variations in geometry will do this sometimes. If it is 1/2 tooth or less off when you string the belt, that is the best you can do in that case. Moving the belt over a tooth will not improve on 1/2 tooth or less. So, do not fret at all if you end up off 1/2 tooth or less. Note that when doing the belt check you should be using TDC on the crank and the tiny TDC notch on the back edge of the cam gear to line up with the backing plate notch.

marine928

Great Bill, once I get the belt on I will rotate a few time and see how things line up. Geometry was not my best subject, probably why I am such a bad pool player.

fraggle

Thanks, Lon. My car has been developing for 8years now. You will have your belt job finished up soon.

Your gears look better than mine. If you switch to the PORKEN'S setup they may last even longer.

marine928

Yep, labor of love AND $$$