Timing belt woes

[belize1334]

I recently purchased a rebuilt head, disassembled it, had it resurfaced and then reassembled it with an all-EVO valve-train. This was done to fix some minor compression issues and a MAJOR leaky valve stem seal. Then, last weak, I bit the bullet, yanked the old head off, installed the new head, replaced the water pump and timing components and then reassembled everything.

The good news is that I seem to have done a good job on the head because it started up and runs.

The bad news is it vibrates so badly that it feels like the keys are gonna rattle out of the ignition. I can only assume that I mistimed it or misaligned the balance shafts. The only problem is, I can't see how? I mean, it's a really simple process. Check my steps, if you will.

I aligned the front shaft sprocket to the mark on the front cover left of the b-shaft driven gear.
Then I aligned the b-shaft drive gear to the mark on the front cover just above and to the right of the front main seal.
Then I installed the b-shaft belt.
I then replaced the spacer plate over the b-shaft sprocket, making sure that the associated timing mark agreed with the timing mark on the b-shaft sprocket.
Then I replaced the timing belt sprocket, which is indexed and can't be messed up.
Then I installed the timing belt with the crank aligned to the same timing mark as before and the oil pump sprocket aligned to it's mark, just above it and to it's left.
At this point I made sure that both cam gears were aligned along their facing timing marks with the dowel pins pointing up.
The timing marks on the cam gear were a little ambiguous and the dowels didn't point exactly straight up but I made sure that the timing marks were aligned through the center of the gear centerlines and that after one crank rotation the outer cam gear timing marks were aligned in the center.

One thing that threw me for a loop. The oil pump sprocket doesn't come back into alignment after a single engine rotation, or two, or even three. It takes four full engine rotations for the oil-pump sprocket to recover it's timing, but at that point I ensured that the front b-shaft sprocket and the cam gears were all properly timed.

So, what gives? If you can spot my mistake I implore -- PLEASE, tell me what I did wrong!

I'm probably not gonna get back to the wrench for a day or so but when I do I'll have pictures to confirm what I *think* I did...

 

[coyotes]

Your balance shaft is likely out of sync.

click watch this video. your balance shaft mark needs to want to naturally center on its alignment mark in order to be in the right spot. If it wants to fall away it is not in the right spot. Or you can take the bolt out of the back of the block as shown in the vfaq writeup to make sure it's in the right spot.

 

[CutlassJim]

It only takes 3 turns of the crank to get the oil pump back inline. The rear balance shaft is 180 out. You need to line everything up with the belt on, remove the belt, turn the oil pump gear 1 more time either way to line the balance shaft back up and re-install the belt. If you doubt it pull the plug on the back of the block and check it with a screw driver.

 

[belize1334]

Ohhhh I get it. The balance shaft spins at a different rate than the outer driven gear because the two gears in the oil-pump housing aren't the same size. That makes sense. I was really getting confused on that 'cause I knew that both b-shafts should spin together and I couldn't imagine why one would spin faster than another. Now I'm wishing that I'd taken a moment to research this when I first became apprehensive about that aspect...

Ok, well that is a huge PITA but it makes sense and it's fixable.

Thanks for the prompt feedback!