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Distributor orientation - reinstall

B

bobct

Advanced Contributor
Does the distributor only engage in two places in the full rotation? I marked mine before I removed it to do the intake gaskets job. I even did a quick video on my phone to document the marks I made. Engine has not been touched/turned over since.

i can't get it to engage and fully drop down anywhere near where I have it marked. I rotated it way off the mark and it drops down so I know it's not an issue of engagement. I did it the other way, again way off and it dropped right down.

I marked the top of the ignition module compared to the tip of the rotor which pointed directly at the throttle cable bracket. I kept going back and forth rotating a little "behind" so it would engage while rotating into the correct position.

I can see the slot at the bottom where it engages to the oil pump which goes back to my original question. Does this mean it can only engage in two places? Or do I need to try something different?

Thanks
Bob
 
bobct said:
Thanks, I saw that before. I think my issue might be mentioned in this article.

http://www.chevyhiperformance.com/techarticles/0609ch_installing_a_chevy_distributor/viewall.html

It sounds like the oil pump get move out of synch when the distributor is removed. It looks like I can rotate it with a screwdriver but how far and which way is the question. This has to be my issue. I'm 100% confident on the marks I made.
Click to expand...


Just found this too:


the oil pump drive shaft will only fully seat up into the distibutor gear at two possisions 180 degrees apart, youll need to align the slot in the pump drive with the slot in the bottom of the distributor, allow for the distributor to turn slightly as the cam and distributor gears mesh as the distributor seats,
a large flat blade screw driver can usually be use to pre-align the oil pump drive so the distributor will fully seat
 
Yes, the distributor will only engage with the oil pump drive in two orientations, 180 degrees apart.

As far as reinstallation, and I know this is with 20/20 hindsight, you need to align the rotor to have it point to something easily referenced on the block and then, once installed all the way "down", align the body/housing (cap) with the block....if you can gleen the rotor orientation from your video, you should be able to figure it out....

Another item of note, and I'm sure you have noticed, due to the drive gear cut, the rotor will rotate a bit as the gear engages....so back the rotor up a bit from the mark and then engage the gear and lower the distributor...
 
ok, that helps. So the oil pump drive must have moved out of position when I pulled the distributor out. I quickly eyeballed this yesterday before I really knew anything and it looks like it was off about 20-30 degrees from where it needs to be. I'm going to go back and take another look today...
 
When you took the Dizzy out, did you notice where the rotor was pointing? If the crank was on TDC, Was it pointing to Cyl #1, or Cyl #6? The oil pump drive gear position don't matter, it moves freely, as long as the Dizzy meshes with it when done. You need to end up with the Dizzy base where you started, if you marked it, and the rotor in position from where you started, as long as the engine wasn't cranked with the Dizzy out!
 
Bob... Let's make it simple for you......


Bring the crankshaft around to TDC C/S for #1 cylinder....
NOTE: this must be on the Compression Stroke.

Stop the crankshaft 6 or 8 degrees just prior to true TDC.

Most of us prefer to see the rotor aiming physically towards #1 cylinder.... although not a deal breaker.
Drop the distributor in and allow it to engage while the rotor is physically aiming towards #1 cylinder.
Make sure that the distributor body orientation meets your needs.
Note: you may be required to move the oil pump drive a bit!

With the distributor now in place and with the plug wires connected, excite the power side (ignition ON)........
With a plug installed in the #1 wire, and with the plug making good Neg contact with the engine.....
Rotate the distributor housing oposite of the rotor and triggering mechanism direction (CCW for the SBC) .....
This will produce one spark event......
Repeat this until you are comfortable that you can stop rotating once you see the spark event.......

This will allow you to fire the engine up!

Once up and running......
Immediately set your BASE advance.
Once BASE is set, be sure to see what your "progressive" and "total" advance are doing.


.
 
RicardoMarine said:
Bob... Let's make it simple for you......


Bring the crankshaft around to TDC C/S for #1 cylinder....
NOTE: this must be on the Compression Stroke.

Stop the crankshaft 6 or 8 degrees just prior to true TDC.

Most of us prefer to see the rotor aiming physically towards #1 cylinder.... although not a deal breaker.
Drop the distributor in and allow it to engage while the rotor is physically aiming towards #1 cylinder.
Make sure that the distributor body orientation meets your needs.
Note: you may be required to move the oil pump drive a bit!

With the distributor now in place and with the plug wires connected, excite the power side (ignition ON)........
With a plug installed in the #1 wire, and with the plug making good Neg contact with the engine.....
Rotate the distributor housing oposite of the rotor and triggering mechanism direction (CCW for the SBC) .....
This will produce one spark event......
Repeat this until you are comfortable that you can stop rotating once you see the spark event.......

This will allow you to fire the engine up!

Once up and running......
Immediately set your BASE advance.
Once BASE is set, be sure to see what your "progressive" and "total" advance are doing.


.
Click to expand...


Ok, I got it. The oil pump drive did move when I removed the distributor. It took me a couple of tries of moving it with a screwdriver and then it dropped right down and exactly where my marks were. I plan on getting it running tomorrow and hopefully my intake manifold gaskets and trans rebuild all check out. Thanks for the replies.

Bob
 
why do so many people insist that the distributor be PHYSICALLY pointing at the number one cylinder ? at TDC, you can put the distributor in any configuration, just as long as you place the wires in the distributor cap to correspond. pointing the rotor at the number one cylinder serves no mechanical purpose whatsoever.
 
crankbait said:
why do so many people insist that the distributor be PHYSICALLY pointing at the number one cylinder ? at TDC, you can put the distributor in any configuration, just as long as you place the wires in the distributor cap to correspond. pointing the rotor at the number one cylinder serves no mechanical purpose whatsoever.
Click to expand...
Technically, you are correct!

I don't care how the Marine Ignition distributor housing is orientated (no vacuum advance diaphragm), as long as there's no conflict with anything else........ the housing orientation does not matter.

However....., to aim the rotor (while at #1 TDC C/S) at the physical location of #1 cylinder, just simply makes good comment sense.
There are no rules, no OEM requirement, etc...... and there is no operational advantage in doing so.... just good common sense.


.
 
crankbait said:
why do so many people insist that the distributor be PHYSICALLY pointing at the number one cylinder ? at TDC, you can put the distributor in any configuration, just as long as you place the wires in the distributor cap to correspond. pointing the rotor at the number one cylinder serves no mechanical purpose whatsoever.
Click to expand...

IMO, the rubbing block on the points, or the ignition module trigger which is attached to the Dizzy base has to be on, or closely coming up to a lobe on the Dizzy shaft, as the rotor faces #1. This will orient your spark plug wires as well. You don't just drop it in Willy Nilly!
 
mikdee.....to restate my point. as long as the number one cylinder is about 5 to 10 degrees before TDC on the compression stroke, yes, you can install the distributor, "Willy Nilly", as long as the distributor sits all the way down fully engaging the oil pump shaft. all you have to do then is install the sparkplug wires in the cap to match the firing order.
 
crankbait said:
mikdee..... to restate my point....... as long as the number one cylinder is about 5 to 10 degrees before TDC on the compression stroke, yes, you can install the distributor, "Willy Nilly", as long as the distributor sits all the way down fully engaging the oil pump shaft. all you have to do then is install the sparkplug wires in the cap to match the firing order.
Click to expand...

Absolutely correct!

But again, many of us who do this profressionally will orientate things so that the distributor's "rotor" is aiming towards the physical location of #1 cylinder while #1 piston is nearing TDC on C/S.

Basically, it becomes a matter of preference and/or experience.
As long as the firing order is correct, as long as the BASE advance is correct, as long as the progressive spark lead is correct, and as long as the TA is correct..................... the Engine will not care what you do!



.
 
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If you drop the Dizzy in, with the rotor pointed to Cyl#1 and the points, or sensor, is not on the lobe, then you have to move the base of the Dizzy to line them up, once you do this, then you're moving the position of #1 on the cap, and have to move all the wires to the next socket on the cap, either clockwise, or anti-clockwise, depending on what's needed.
 
Once the dist drive gear connects with the cam all you need to do is rotate the motor until the oil pump shaft matches the dist slot.
The actual timng is not affected. once it lines up ,the dist will just dropdown in place.
A alternate method is to turn the pump shaft with a long screwdriver o line it up
 
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