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  View original topic: setting distributor on engine rebuild
txasylum Tue Jan 07, 2020 5:41 am

My book is at home, but I'm at work. This is on my mind and I've searched the web, but did not find the answer.

When putting cases together, how do you ensure or know that your timing is set to #1? I know how the distributor shaft should look in the hole to be on #1, but do you turn the crank so that #1 piston is all the way out? Or is it based the timing mark alignment between the crank and cam?

Glenn Tue Jan 07, 2020 6:24 am

First thing I do is install the distributor drive and use a dummy distributor to keep it in place. Then i install the crank with the #1 rod fully extended (TDC).

Then when you install the camshaft, you use the dots on the gears.




Sharp64 Tue Jan 07, 2020 6:27 am

The procedure is in the book and Iím not at home but roughly from what I remember you set the distributor in so itís at TDC and then when you place the crank on with the rods, make sure #1 is at TDC. Then when you put the cam in, you make sure the marks on the cam gears line up. Someone correct me if Iím wrong.

txasylum Tue Jan 07, 2020 6:44 am

Great, that is what I was thinking, but it was bugging me here at work and just had to find the answer.



Glenn wrote: First thing I do is install the distributor drive and use a dummy distributor to keep it in place. Then i install the crank with the #1 rod fully extended (TDC).

Then when you install the camshaft, you use the dots on the gears.




txasylum Tue Jan 07, 2020 6:46 am

Thanks. That is what I thought, but just wanted to confirm.


Sharp64 wrote: The procedure is in the book and Iím not at home but roughly from what I remember you set the distributor in so itís at TDC and then when you place the crank on with the rods, make sure #1 is at TDC. Then when you put the cam in, you make sure the marks on the cam gears line up. Someone correct me if Iím wrong.

viiking Tue Jan 07, 2020 2:39 pm

txasylum wrote: Great, that is what I was thinking, but it was bugging me here at work and just had to find out

You should be thinking about office politics and that rotten boss, not daydreaming about Volkswagens. Get back to work!😂

txasylum Tue Jan 07, 2020 4:03 pm

Tough to get work done with you have VW's on your mind.... LOL


viiking wrote: txasylum wrote: Great, that is what I was thinking, but it was bugging me here at work and just had to find out

You should be thinking about office politics and that rotten boss, not daydreaming about Volkswagens. Get back to work!😂

ashman40 Thu Jan 09, 2020 12:07 pm

Just to clarify a few points....
(Orient distributor drive gear) Install the distributor drive gear as show above in the #1 TDC orientation. Larger portion offset towards the flywheel. Smaller portion towards the crank pulley.

Look at the bottom of the distributor and work out how the cog at the bottom of the distributor will engage with the offset slot in the top of the distributor drive gear. Note WHERE the rotor will be pointing when the distributor is installed. Is it 1-o'clock, 4-o'clock or 7-o'clock? Different distributors will point to different points around the cap. Don't assume the #1 plug wire goes somewhere it doesn't.

(Orient distributor) Without rotating the drive gear in the case install the distributor so it seats fully into the case and proper engages the end of the drive gear. The rotor is now pointing to where the #1 plug wire MUST be installed so rotate the body of the distributor (not the rotor) until the #1 plug wire notch on the rim of the distributor body lines up with the tip of the rotor. Clamp down the distributor so the body no longer moves. The notch in the distributor body now represents the #1 plug wire position.

(Orient the crank) Drop the crank into the case with the #1 connecting rod fully extended (TDC). Make sure it cleanly meshes with the teeth of the distributor drive gear. The crank and distributor drive gear are now in the #1 TDC position.
In this position you should notice that the two dots on the crank gear are at 3-o'clock (closest to the #2 cylinder; 90deg from the case split line) and NOT lined up with the case as pictured above.

(Orient the cam) Engage the cam gear with the crank gear so the single dot on the cam gear meshes between the two dots of the crank gear. Slowly roll the cam into position in its saddles while maintaining gear mesh with the crank (do not rotate the crank). The cam will rotate 45 deg as it rolls into position. Once seated the dot on the cam gear will be 45deg CW from the case split.

Slowly rotate the crank CW 90deg. When the cam gear dot is lined up with the case split the two crank gear dots should now be on either side of it... as pictured above. If you mount the crank pulley it should be reading 90ATDC. The gear dots DO NOT mesh/line up at TDC.


The crank + cam + distributor drive gear are now properly oriented together and the notch in the distributor rim properly indicates where the #1 plug wire is installed on the cap.
If you want to check this... rotate the crank CCW until the TDC mark on the pulley lines up with the case split. Check that the #1/#3 cam lobes are pointing towards the #3 cylinder and the base circle of the lobes are facing the #1 cylinder. This confirms that the cam is in position so both #1 valves are closed. Look at the distributor and the rotor and the rotor tip should be pointing to the notch. This confirms when the cam is at #1 TDC the rotor is pointing to the #1 plug wire on the distributor. As long as you install the #1 plug wire over the notch in the distributor body the coil will deliver the spark to the #1 cylinder.


A common mistake is to orient the distributor so it points where you THINK it should point for the #1 plug wire rather than letting the steps determine where #1 plug wire should be installed. You can do this, but then the distributor drive gear orientation will be wrong.

Zundfolge1432 Thu Jan 09, 2020 12:46 pm

Sounds good a bit wordy maybe hard to visualize for a newbie. Try this lay the crank and cam line up dots. Now just barely install crank pulley and align the timing mark with case split line, look at the cam lobes you want to see that lobe which opens #1 exhaust coming around to open it, remember cam turns opposite direction. Install drive gear fat side of cutout facing flywheel. Now no matter which distributor you use it will be oriented correctly. Once you are sure everything is correct always install fuel pump to keep the distributor gear from riding up and damaging the brass gear and causing another set of problems.

sjbartnik Thu Jan 09, 2020 12:46 pm

Thanks for posting this, ashman40. I coincidentally was thinking about this last night when I noticed that the two dots on the timing gear do not straddle the case parting line when the #1 connecting rod is in TDC position. Itís not really explained well in the Wilson book but after thinking about it some I came to the conclusion that the procedure for setting the distributor drive up properly relative to the crank and the procedure for setting the camshaft up relative to the crank are two separate procedures unrelated to each other.

Your post above confirms that the conclusion I came to was correct so that puts my mind at ease.

EDIT: or, in other words - when you set up the distributor drive pinion, put the crankshaft so that the connecting rod for #1 is at TDC (fully extended) and donít worry about the dots on the timing gear.

Then when you set up the camshaft, put the cam gear dot between the crank gear dots and donít worry about the distributor or TDC.

ashman40 Thu Jan 09, 2020 3:13 pm

sjbartnik wrote: Then when you set up the camshaft, put the cam gear dot between the crank gear dots and donít worry about the distributor or TDC.
There is one case where this isn't true, but it requires the person do something sort of silly while assembling the engine...
After placing the distributor drive gear and crank in place at #1 TDC... before you install the cam gear you "accidentally" rotate the crank 360-deg before you engage the cam teeth. The crank gear will look exactly the same but the distributor drive gear will be rotated 180deg. When you mesh the cam gear with the crank it will look completely fine. But if you check that the rotor is pointing to the #1 plug wire position while the cam lobes are pointing towards #3 cylinder you will find the rotor is is now pointing to the #3 plug wire post instead of #1 (distributor 180-out).

sjbartnik Thu Jan 09, 2020 4:23 pm

Good point - the two dots on the timing gear come around more often than the single dot on the cam gear.

Glenn Thu Jan 09, 2020 6:20 pm

The crank rotates 720* while the cam rotates 360*. Same for the distributor.



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