Rotor orientation

[seapadrik]

Hello,

I am in the final stages of my rebuild and am now to the distributor chapter.

I read in the manual the rotor should be pointed away from the block when cylinder 1 is at TDC.

I also read in another thread here that the rotor should be at 3 o clock ??

Well here is a photo taken from above when cylinder 1 is at TDC. From above I would call this 7:30 or 8:00 o clock.

Please tell me what time that rotor should be. Also there didnt seem to be many ways to set that plastic rotor down on the stem, so can I assume if I need to rotate that, I leave the plastic rotor where it is and just lift up the entire distibutor and set it back down, while adjusting a few degrees ??

Thanks

[sastanley]

you're close...spin your orientation around from over the water pump & that puts the rotor in your picture at about 2 o'clock!

does this pic help?
http://www.moyermarine.com/forums/attachment.php?attachmentid=1398&d=1241526240

[ILikeRust]

Ultimately, exactly which direction the rotor is pointing relative to the block is not critical. What is critical is which sparkplug wire it is under at any given moment in time.

When cylinder 1 is on TDC of the ignition storke (and make sure you are on the ignition stroke and not the exhaust stroke), you want the rotor to be right under the number 1 sparkplug wire.

The book offers a simple way of doing it by saying make the rotor point directly away from the block. So if you were standing at the back end of the engine and looking down on the distributor, the rotor would be at 3:00. Then put the cap on, and make sure the number 1 sparkplug is also at 3:00. This way, the rotor is right under the #1 sparkplug wire at the same time cylinder 1 is at TDC.

You could do the same thing by pointing the rotor at 12:00 or any other place you want to point it, and just make sure the #1 sparkplug wire is right above it when the #1 cylinder is at TDC.

If you do need to adjust where the rotor is pointing, then yes, you simply remove the bolt that holds the distributor down, lift the distributor straight up, move the rotor over and carefully put the distributor back in. You'll find that the rotor moves slightly as you drop the distributor in, because of the spiral gears.

[seapadrik]

Thank you sir ! I guess it proves the whole clock reference is only effective if you have the right orientation to begin with.

So to recap, based on my original pic, it needs to be at 9:00 o clock. Based on your description, if I were standing at my reverse gear side of the engine facing the flywheel, whiile hovering above it would be 3:00 o clock.

Although it is interesting because we use the term cylinder 1 while standing at the flywheel like I was originally.

Cheers

[sastanley]

Yes...what you said.. :D

Hopefully, using Bill's advise, you can pick up the dizzy and turn the shaft one set of teeth in the gear and it will magically re-align into the 9:00 position when you set it back down (using your photo) :cool:

[roadnsky]

If I remember correctly, Don's explanation of why we point #1 directly away from the block is because there is a very tight clearance between the Alt Pulley and the Distro Cap.
This orientation allows for the best adjustment "play" when timing.

At least that was my understanding... :cool:

[Kurt]

Correct Roadnsky! I learned this the hard way, of course. Yes, you can theoretically have the rotor oriented any which way as long as it is under the number 1 spark plug wire at TDC. However, I discovered that any other orientation on a late model engine will likely result in the alternator pully rubbing on the distributor cap. On my engine, when the rotor was not oriented correctly I only noticed the belt rubbing when I took a look at the engine after running for a bit and it was happening right before my eyes. It was not an overly obvious clearance problem, but significant enough to want to follow the rotor orientation guidelines.

I believe early model engines favor the rotor pointing at 6 o'clock (towards the reversing gear) - probably for the same reason, but I'm not sure on that one as I am only familiar with the late model A4.

[ILikeRust]

Good to know!

I've been running my engine without the alternator, because the alternator is 85 miles away - still on the boat. So I unaware of the clearance issue.

[jpian0923]

Early models still need to point directly away from the engine.

Although a smaller distributor, the spring clips will have clearance problems and removing and replacing distributor cap would be difficult.

Bill, fix it before you put alt back on. FYI

[ILikeRust]

To be clear, I did my timing completely by the book, so my #1 wire is at 3:00, exactly as Don and Universal specify.

So I should be good to go when I reattache the alternator.

[jpian0923]

180 off is completely by the book?! :D
Just kidding Bill. We've all made that mistake before.

[ILikeRust]

I meant NOW, not BEFORE.

Sheesh. :p