Intake manifold, 350 GM

[rickasbury]

When you have it all lined up before you pull it out you make a mark on the distributor body that lined up to where the rotor is pointing. Or when you still have the cap on the distributor find the receptacle for the #1 plug wire in the cap and make a mark on the body of the distributor straight down from it. That way you always know where the rotor should point for #1.

I wish someone good explain where my thought process is wrong. Its coming out and going back in. As long as everthing is pointing the same way as when it came out, why does it matter what it's pointing at? Nothing is going to move. If i dont need to pull the plugs to get it to TDC, in my mind for nothing, I would want to avoid it. Some of the plugs are hard to get to and recently replaced rotor, plugs and wires.

 

[alldodge]

As long as everthing is pointing the same way as when it came out, why does it matter what it's pointing at?

Your correct, we are just thinking of ways to make sure, but as you say if it goes back in at same exact place then there should be no issue

 

[rickasbury]

Your correct, we are just thinking of ways to make sure, but as you say if it goes back in at same exact place then there should be no issue

If something moves then I'm in trouble . Might be after christmas as we are goingvon a cruise that week...I will follow up with pictures!
Thanks for the input as always!

 

[Lou C]

Reason is:
if somehow the distributor shaft moves when it's out, with the engine at TDC, compression stroke of #1, that is a known correct position and if you have a mark on the distributor body where the #1 plug wire connects you can't be off. If you just pull out the distributor at some random position, how do you get it back there if it moves, it could be between 2 terminals for 2 cylinders, that is a lot of room for error and your timing will never be right.
Also
if you're going to work on these engines, this is a basic skill that should be acquired, just like setting the hydraulic lifter lash adjustment (modern Chevrolets don't have this but all the classic ones do, till they went to the net lash design).
It is simple enough to do, when you understand what you're looking for.
When I did the hydraulic lifter adjustment after changing the heads, I marked on the cyl head , the # of each cyl and whether each valve was an intake or exhaust, that made it goof proof (mostly lol).

 

[rickasbury]

I've never seen a complete rotor asy out and in my hands. I'm looking at pictures online, it looks like i can mark the housing where it is pointing..i can mark the tube and the intake ( i will use a punch on the intake, a scribe of some sort on the tube unless I can dimple that with a punch). Also, once I have it that close, isn't there a slot on the bottom that engages the oil pump? Does that help align also? It looks like the shape of the rotor top will also only sit one way. As long as nothing moves on the motor..and I could mark the flywheel too- the worst that can happen, if something moves then I should see it and I have to go to TDC . If i can save pulling all the wires and plugs that is a huge timesaver for this project. I still want to bench test the altenator as well as replace the water impeller...so I have a list! Rotor/cap/wires/plugs all recently replaced.

 

[Lou C]

You don't have to pull wires and plugs
do you have the crab cap or the conventional cap?
the thing is figuring out which plug wire is for #1 cyl and follow that back to the cap. I never had an engine with the crab cap so I don't know if it's easy to tell which terminal on the cap is for #1 plug wire. I'm sure someone on here knows though, because they are common on later engines.
I have a couple of spare distributors (old style cap) that I can post up a pic of.

 

[alldodge]

Lou he has the flat cap

 

[Lou C]

That's what I thought.
I bet it identifies where #1 is in a Merc shop manual.

 

[alldodge]

That's what I thought.
I bet it identifies where #1 is in a Merc shop manual.

The cap terminals are numbered