I had a few posts up recently about gremlins in my 86 iroc, 305 tpi auto that i have been fighting, you can see them if you search a page back. Anyway, i changed out my timing chain, which was still original. (Nylon, or whatever cam gear) It has a TON of slack. Before i took it apart, i lined up the balancer mark with 0*. I then took out the distributor cap, and pulled the lower manifold. I installed the new crank timing gear, and chain, lubbed the heck outt it, verified the timing marks were perfectly aligned. (cam at 6 oclock, crank at 12 oclock) and put everything back together. The distributor wants to drop in pointing a cylinder 6. The only other way it drops in is pointing at the firewall. I never rotated the engine around with the distributor out. I just dont remember where the dizzy was when i pulled it. Does it sound ok? Thanks guys.

 

It doesn't matter, stabbing the dizzy is relative. What you can do is, put the dizzy in the way YOU want it, if it doesn't go down bump the starter while someone is holding the dizzy. It will drop down and should be ready to run.

Same w the dot-dot alignment, 6 o clock, 12 o clock...all relative, it only matters for the dizzy TDC on intake or exh stroke.

 

If you installed the timing chain "dot to dot" (6 and 12) then you WANT the rotor pointing at #6, since that TDC/compression stroke for #6. If you roll the motor over 360* (both dots at 12:00) then you're on TDC/copmpression of #1.

DO NOT CONFUSE THIS WITH WHERE THE DISTRIBUTOR "WANTS" TO DROP IN. The distributor has 13 teeth on the bottom and will drop in on any one of those 13 positions. It's the oil pump driveshaft that will only allow 2 positions to drop all the way home at any given time. The position of that oil pump driveshaft is anybody's guess once you've had things apart, rolled the engine to set the valves, etc. If the distributor doesn't want to drop home where it NEEDS TO BE POINTING then you get out a big long screwdriver and turn the oil pump driveshaft a little and give it another shot. (making a mark on the back of the screwdriver handle that corresponds with the blade on the bottom is a very helpful reference mark for this kind of work).

Don't let the oil pump driveshaft dictate where your distributor drops in- you have to tell it where you need it to drop in. Takes a little practice, but do it once or twice and you'll get the hang of it. The main thing is remembering that the rotor will turn about 30* as you drop the distributor all the way home. So the oil pump driveshaft has to engage the bottom of the distributor gear and then get "carried" along with it as it rotates the rest of the way and drops all the way home.

 

Ok, so you are saying i should be good then? I was thinking i needed to be pointing more at cylinder 1, but i want to keep it original in terms of firing order, so ill leave it alone. Thank you so much for the quick reply!

 

one more question. What about this whole being "off by a tooth" thing. How can I verify I get it perfect?

 

The whole "being off by a tooth" thing is a myth. Since you have to adjust the timing anyway, it is impossible to be off by a tooth. You simply have to move your distributer to get it into time.

 

it's already very well explained
if you know your # 1 piston is @ TDC.. get a flashlight and look at the oil pump shaft []
aim the slot in the middle of the I / E valve springs... when you drop the dist in it will turn the Dist shaft about 3 teeth
to prevent this start with the dist shaft 3 teeth <> before the oil pump slot this will look like it's aiming @ the end of # 3 piston <> this will be dead on

it wont be off by 1 -3 teeth it will just limit your rotation when timing!!!!!