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Static Timing the Distributor, Uh-oh
Posted by: Frog ()
Date: May 09, 2020 07:44PM

At first, I was just confused; now, I’m really worried.

I set number one piston to TDC on compression stroke.

I have the 95-horsepower engine with manual transmission, so I adjusted the harmonic damper to indicate 6 degrees BTDC (first image).

I installed brand-new distributor.

I rotated the distributor with breaker tab on top of cam; points open. My mind tells me—as do all the illustrations—that with this setup, the tip of the rotor should be right in front of the distributor point of the number one spark plug. IT’S NOT. (See other images.)

You can clearly see there’s a large angle between the location of the number one spark-plug contact, and the direction the rotor tip is pointed. It clearly is not aligned with the distributor point for the number one spark plug. The only reason I can come up with why I have this situation is that the alignment of the timing marks on the camshaft and the crankshaft gears is incorrect.

I took every precaution, and checked, and double-checked the alignment of those points on the cam and crank gears before buttoning up the case—or so I thought.

Any thoughts? Is there something so obvious that I’m missing it?

Thank you.
Frog

Rob Lane
Clayton, in the Northeast Georgia Mountains.
1964 500 Coupe
Purchased by me in April of 1964.



Edited 1 time(s). Last edit at 05/13/2020 09:35PM by MattNall.

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Re: Static Tuning the Distributor, Uh-oh
Posted by: wittsend ()
Date: May 09, 2020 08:03PM

There is a slot in the oil pump that the bottom of the distributor tip (looks like a large blade screwdriver) slides into. Sometimes upon installation as one giggles the distributor into place mating to that slot will cause the distributor to be off a tooth (or more).

Remove the distributor and look where the distributor "screwdriver " (so to speak) is pointed when the rotor is positioned at the cap #1 position. Then with a real screwdriver (a long one) position the slot in the oil pump accordingly. Reinstall the distributor with the rotor pointing at #1 on the cap.

Lastly the gears are helical cut so there is slight twisting rotation upon installation. So that can shift the rotor location slightly. Usually the rotation of the distributor allows for that compensation. I have had a bunch of Datsun 510s and the distributor and oil pump configuration is very similar to the Corvair. Hope that helps.

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Re: Static Tuning the Distributor, Uh-oh
Posted by: MattNall ()
Date: May 09, 2020 08:21PM

You forgot about our STICKIE : FAQ's????GGGG

To re-install distributor:

A Remove sparkplug from #1 [ closest to dist.]

B Crank engine with starter with finger in hole.

C When pressure blows your finger out...STOP

D Timing mark will have passed the timing guide / rotate pulley CW until

the timing mark on the pulley is at 14 DEG. STOP DO NOT MOVE ENGINE!!

E With dist. in your hand.....point rotor towards VA diaphram...1" below VA

F Look at bottom of Dist. shaft......with VA pointed at rear bumper /

determine where the oil pump SLOT should be....taking into account the gears are

angled and the Rotor will turn approx. 1/8 turn...

G Align oil pump slot...........install dist. [ gasket!] and insert dist.

until it bottoms out at gasket surface...if not move oil pump shaft slightly...

H Add holdown clamp and tighten with fingers.

I Connect wire from Dist. to "-" of coil

J Add Dist. cap / Coil lead and # 1 SP wire.....with sparkplug in! Hold SP against metal.

K Turn on Ignition..DO NOT CRANK ENGINE

L By hand..Rotate Dist CW all the way it will go [ hits eng.]

M Rotate CCW slowly until #1 SP fires STOP Tighten down dist.

NOTE: if you set the points right / have spark...there is no reason to move

the Distributor. ANY engine will run with this timing. Any problems with missing / bad idle is the Carbs or the Sparkplugs /wires, etc.

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Static Tuning the Distributor, Uh-oh
Posted by: JimBrandberg ()
Date: May 10, 2020 05:55AM

I'll just say the same things in a different fashion.
Yes I would say you're one tooth off. Pull the distributor, turn the oil pump counter-clockwise a tad with the long screwdriver and reinsert the distributor. It might take a few tries if you don't turn the oil pump enough or turn it too much.
I like the position that you're installing it with the vacuum advance cover parallel with the rear chassis frame rail. You could accomplish proper orientation with the distributor turned so the vacuum advance cover is angled but I don't like that as much. It needs to be angled when there's an additional belt for AC or Smog.
If the oil pump slot is not aligned the distributor will not go all the way in. Sometimes you need to sort of click it up and down a bit for it to slide into place. You can tell where it's at by withdrawing the distributor partway to move over a tooth.
Your appraisal of it being off is correct so you're showing good common sense.

Jim Brandberg
Isanti, MN
CorvairRepair.com



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Re: Static Tuning the Distributor, Uh-oh
Posted by: vairmech ()
Date: May 10, 2020 06:05AM

The one thing to look at is to make sure that the gear on the shaft is put on correctly.

It's simple to look at, there is a dimple in the smooth portion, that is supposed to line up with the rotor pointer or the notch in the upper shaft. If it doesn't either the gear is put on backwards or the points cam is put in backwards.

Ken Hand
Handy Car Care
248 613 8586

Vairmech@aol.com

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Re: Static Tuning the Distributor, Uh-oh
Posted by: Wagon Master ()
Date: May 10, 2020 06:13AM

Good point. Does it matter which way the point cam in orientated on the dist. shaft?

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Re: Static Tuning the Distributor, Uh-oh
Posted by: RexJohnson ()
Date: May 10, 2020 10:00AM

The dist being off a tooth would not change the relationship between the point cam and the housing which holds the cap. If you move the shaft one tooth you will need to move the housing one "tooth" distance to have the points opening at the same time.

RJ tools
Salem,Oregon

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Re: Static Tuning the Distributor, Uh-oh
Posted by: Richard ()
Date: May 10, 2020 11:28AM

>> with breaker tab on top of cam; points open.<<

Are you talking about the breaker point rubbing block at the top of the cam lobe and you have maximum point gap?

That isn't when ignition occurs.

Ignition occurs when the points open.

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Re: Static Tuning the Distributor, Uh-oh
Posted by: vairmech ()
Date: May 11, 2020 05:51AM

Wagon Master Wrote:
-------------------------------------------------------
> Good point. Does it matter which way the point cam in orientated on the dist. shaft?
>>>>>>>>>>>>>>>>>>>>>>>>>>

Yes!

Ken Hand
Handy Car Care
248 613 8586

Vairmech@aol.com

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Re: Static Tuning the Distributor, Uh-oh
Posted by: 66vairman ()
Date: May 11, 2020 04:24PM

It has been posted here in years past that "rebuilt" distributors from FLAPS don't always have the correct parts per the number on the distributor case.

I got a good rebuild from a reliable Corvair vendor, but one part was wrong. I'm glad I dismantled it and verified all the part numbers. The vendor agreed with me and sent out the correct replacement part.

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Re: Static Tuning the Distributor, Uh-oh
Posted by: Wagon Master ()
Date: May 11, 2020 05:11PM

vairmech Wrote:
-------------------------------------------------------
> Wagon Master Wrote:
> -------------------------------------------------------
> > Good point. Does it matter which way the point cam in orientated on the dist. shaft?
> >>>>>>>>>>>>>>>>>>>>>>>>>>
>
> Yes!


Is this outlined in a service manual?

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Re: Static Tuning the Distributor, Uh-oh
Posted by: vairmech ()
Date: May 11, 2020 05:30PM

The dimple in the gear lined up with the notch for the rotor is in the shop manual but not the placement of the point cam.

The point cam will go on in either hole in the shaft but one way the spring posts are far apart and the other way they almost line up. I think this might be detailed in the tech guide.

Ken Hand
Handy Car Care
248 613 8586

Vairmech@aol.com

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Re: Static Tuning the Distributor, Uh-oh
Posted by: Frog ()
Date: May 14, 2020 07:03AM

Thank all of you for your responses.

Richard said in reference to someone else’s reply to my topic: “That isn't when ignition occurs. Ignition occurs when the points open.” (My emphasis.)

That statement infused clarity in my mind, and unraveled MOST of the mechanical questions I was wrestling with trying to set up this distributor.

I kept visualizing that the “spark” occurs when the breaker’s cam follower (tab) is at its highest point on the cam lobe. All the drawings I saw led me to believe that at the moment of spark, the rotor tip is aligned with the distributor-cap contact when the breaker tab is atop the lobe. Now I realize that that’s not the case.

Now, after reading Richard’s statement, of course the points begin to open several degrees before the breaker-point tab is atop the cam lobe. (I validated that for myself on my distributor shaft.) At the instant the points begin to open, the power of the collapsed EMF around the primary wiring of the coil is unleashed. THAT’S when the rotor contact is supposed to be aligned with the distributor contact. Right?

I finally came across a graphic (attached) which I believe accurately demonstrates the position of the rotor-tip contact in relation to the distributor contact at the time the points begin to open. As you can see in the drawing, the points open short of the top of the lobe of the shaft (This coincides with Richard’s statement, above). The drawing also shows that the rotor contact at the time of the spark is aligned with the appropriate distributor-cap contact. This also means that the rotor tip is well past the distributor-cap contact when the breaker tab is atop the lobe. (Call me Captain Obvious.)

With all this said, the goal is to set up the distributor so that at the moment the breaker contacts open, the rotor tip is aligned with the appropriate contact on the distributor cap (number one). Right? AND, I’m guessing that the instructions provided by MattNall result in that. Right?

Now, I have some questions about those instructions. I understand and performed items A, B, and C. Item D says Timing mark will have passed the timing guide/rotate pulley CW until the timing mark on the pulley is at 14 DEG. STOP DO NOT MOVE ENGINE!! I had no problem performing that function; however, I’m wondering why “14 DEG.” I’m guessing that this number is used because it corresponds to timing specification for the 1964 110HP, 150HP, and 95HP (with auto transmission) engines. Because my engine is the 95HP with manual transmission, I should set the timing mark at the specified 6 DEG. Right? (Captain Obvious, again? Give me a break. God willing, I’ll reach 77 in a couple of weeks.)

Items E and F are throwing me off. With dist. in your hand.....point rotor towards VA diaphragm...1" below VA. I’m not sure what “1 inch below VA” means.

Item F says Look at bottom of Dist. shaft......with VA pointed at rear bumper/determine where the oil pump SLOT should be . . . What exactly do I point at the rear bumper?

The rest of the instructions I understand, but because my engine’s on the bench, I don’t know how to set it up so I can actually test for a spark at the number one spark plug.

By the way, the dimple alignment mentioned by vairmech is correct.

I know all this comes naturally to you folks and I appreciate your patience in dealing with me.

Thank you.

Frog

Rob Lane
Clayton, in the Northeast Georgia Mountains.
1964 500 Coupe
Purchased by me in April of 1964.

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Re: Static Tuning the Distributor, Uh-oh
Posted by: MattNall ()
Date: May 14, 2020 07:54AM

Glad you got it!

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Static Timing the Distributor, Uh-oh
Posted by: JimBrandberg ()
Date: May 14, 2020 07:55AM

Frog wrote:
"The rest of the instructions I understand, but because my engine’s on the bench, I don’t know how to set it up so I can actually test for a spark at the number one spark plug."

--------------------------------------------------------------------------------

Since spark occurs when the points open you can put a cigarette paper between the points and when you can withdraw it is when the points are opening. You can either do this by turning the engine or rotating the distributor. Probably easier to set the engine, rotate the distributor and then tighten down. It's the reason I like the VA cover parallel with the rear of the engine as a rough guide.

You are correct in assuming 14 degrees is a figure for more common 110 and 140 HP distributors and your's may be different like 6 for some 95 HP.

I learned this in 1970 or so when cigarette papers were more common. Any thin and pure paper will work.

Jim Brandberg
Isanti, MN
CorvairRepair.com






Edited 1 time(s). Last edit at 05/14/2020 07:56AM by JimBrandberg.

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Re: Static Timing the Distributor, Uh-oh
Posted by: Richard ()
Date: May 14, 2020 09:47AM

>>Items E and F are throwing me off. With dist. in your hand.....point rotor towards VA diaphragm...1" below VA. I’m not sure what “1 inch below VA” means.

Item F says Look at bottom of Dist. shaft......with VA pointed at rear bumper/determine where the oil pump SLOT should be . . . What exactly do I point at the rear bumper?<<

Matt is just talking about installing the dist into the engine. You install it with the rotor and the #1 plug wire tower at the rear of the engine, next to the rear bumper. Why Chevy numbered the cylinders from the rear of the engine to the front is a mystery to me.
When viewed from the rear, the engine turns CCW and the dist turns CW.
This image from Clark's catalog shows the #1 tower and rotor pointing to the rear.

Other than standardizing the plug wiring positions, the dist just has to be able to swing far enough to be able to a adjust the base timing and not hit anything.

The phasing or indexing of the rotor to the cap towers is pretty much fixed in the distributor, but it isn't locked in one spot. The phasing shifts as rpm increases and/or as vacuum advance is added.
This MSD image shows the phasing at one side of the rotor tab and ideally would only move to the other side of the tab as timing advance is added.

>>Frog wrote:
"The rest of the instructions I understand, but because my engine’s on the bench, I don’t know how to set it up so I can actually test for a spark at the number one spark plug."<<

A couple of ways. Do you have an ohm meter or continuity tester? Connect it across the dist wire to ground. Points closed, continuity buzzer sounds. Points open, buzzer off. rock dist back-and-forth. Lock the dist down at the location the points OPEN.
Use a 1.5V battery and small lamp as a continuity checker.

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Re: Static Timing the Distributor, Uh-oh
Posted by: Frog ()
Date: May 15, 2020 01:18PM

Richard and Jim,

Richard, I couldn't figure out where to locate the leads on my multimeter to test for spark.

I did use Jim's method of a strip of paper between the contacts. As it were, where the paper slid out from between the points just as they opened, the rotor just happened to be aligned with the number one distributor point.

With the help of all you folks on this distributor thing, it would appear as if all is well with the settings. This a milestone for me.

The next milestone is getting gasoline to the carbs. I've seen several suggestions on how to do that. I'm reluctant to remove the tops of the carbs and simply pour some fuel in. There are simpler ways, for sure.

Oh, in my little town in the Northeast Georgia Mountains, we actually have a filling station that sells 100-percent gasoline, which seems to be the choice among you aficionados.

Thanks again for all your help. Rest assured you'll be hearing from me again.

Frog

Rob Lane
Clayton, in the Northeast Georgia Mountains.
1964 500 Coupe
Purchased by me in April of 1964.

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Re: Static Timing the Distributor, Uh-oh
Posted by: American Mel ()
Date: May 15, 2020 07:59PM

Not sure who would want to remove carb tops to fill fuel bowls!?!? eye rolling smiley
NO one I know does it THAT way.
Like you said, many ways to do it, that one is not near the top of the list.

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WA. state, 1 mile south of the Canadian border,
I am not at the end of the world, but you can see it from here.
Have; '66 Monza Coupe - 140, 4-spd. Daily driver beater
'67 Monza Vert. - 140, 4-spd. Daily driver beater
'67 A/C Moredoor Monza
Have had; '61 Monza coupe, 80hp, PG
'62 Monza Wagon, 4spd.
'63 Spyder,
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.
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Re: Static Timing the Distributor, Uh-oh
Posted by: joelsplace ()
Date: May 16, 2020 07:09AM

Use a small squeeze bottle to fill the carburetors through the vents.

Joel
Northlake, TX
5 Ultravans, 114 Corvairs and counting...

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Re: Static Timing the Distributor, Uh-oh
Posted by: Frog ()
Date: May 19, 2020 01:13PM

Joel of Northlake,

Do you mean remove this and squirt fuel into the orifice?????

Rob Lane
Clayton, in the Northeast Georgia Mountains.
1964 500 Coupe
Purchased by me in April of 1964.

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