Author Topic: ignition timing  (Read 1263 times)

wisemanz28

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ignition timing
« on: March 02, 2012, 08:15:37 PM »
I'am installing the distributor on my 69 302 engine. When the motor is at tdc and the distributor rotor is pointed directly at the number 1 cylinder and I install the original cap, it puts my number 1 wire on the right side of my points door. How can I adjust the distributor so the number 1 wire lands to the left of the points door?
« Last Edit: March 02, 2012, 09:50:13 PM by wisemanz28 »

1968RSZ28

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Re: ignition timing
« Reply #1 on: March 02, 2012, 09:11:18 PM »
I'am installing the distributor on my 69 302 engine. When the motor is at tdc and the distributor rotor is pointed directly at the number 1 cylinder and I install the original cap, it puts my number 1 wire on the right side of my points door. How can I adjust the distributor so the wire lands to the left of the points door?

Use a long, thin screwdriver to align the oil pump drive shaft slot (at the bottom of the distributor mounting hole) with the distributor drive tang.

Paul

wisemanz28

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Re: ignition timing
« Reply #2 on: March 02, 2012, 10:05:19 PM »
Paul shouldn't the rotor be pointed at the number 1 cylinder at tdc? If I put the cap on the distributor and keep the number 1 wire positioned to the left of the points door, acually the rotor will be positioned over the number 2 wire or to the right of the points door. I'm confused.

TODD

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Re: ignition timing
« Reply #3 on: March 02, 2012, 10:33:10 PM »
you need to bump it a little more counter-clockwise the distributor is a worm type gear and the shaft will rotate clockwise when dropping into place

Mike S

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Re: ignition timing
« Reply #4 on: March 02, 2012, 10:39:34 PM »
I recommend this...
I used to use the screw driver method but finally tried this last weekend was was surprised how easy and fast the distributor indexed itself.

I found this article that describes a neat method to "walk" the distributor into position. I
http://www.corvette-restoration.com/resources/technical_papers/Distributor_Installation.pdf

This one has links to You Tube examples
http://www.classiccarauto.com/impala/how_to/install_distributor.shtml

Good luck!
Mike
67 LOS SS/RS L35 Hardtop - Original w/UOIT
67 NOR SS/RS L35 Convertible - Restored

1968RSZ28

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Re: ignition timing
« Reply #5 on: March 02, 2012, 10:41:45 PM »
Paul shouldn't the rotor be pointed at the number 1 cylinder at tdc? If I put the cap on the distributor and keep the number 1 wire positioned to the left of the points door, acually the rotor will be positioned over the number 2 wire or to the right of the points door. I'm confused.

Assuming the oil pump drive shaft slot is in the correct position, you still have to make one more positioning adjustment of the distributor before lowering it into position.  Because of the helix (angle) of the distributor gear teeth, the distributor will turn as you lower it in place.  To compensate for this rotation, turn the distributor in the opposite direction the same amount the gears cause the rotor to turn.

Paul

JohnZ

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Re: ignition timing
« Reply #6 on: March 03, 2012, 03:20:34 PM »
Paul shouldn't the rotor be pointed at the number 1 cylinder at tdc? If I put the cap on the distributor and keep the number 1 wire positioned to the left of the points door, acually the rotor will be positioned over the number 2 wire or to the right of the points door. I'm confused.

At #1 TDC (on the compression stroke), the rotor should be pointed at THE #1 WIRE TOWER IN THE CAP,  not at the #1 cylinder location at the left front of the engine. Photo below shows the correct distributor housing orientation and wire indexing in the cap.
'69 Z/28
Fathom Green
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wisemanz28

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Re: ignition timing
« Reply #7 on: March 03, 2012, 05:29:35 PM »
I always thought that proper timing was when the distributor,s rotor was pointing at the number 1 cylinder. Your posts imply a  different position (around number 2 cylinder), is this correct ?

JohnZ

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Re: ignition timing
« Reply #8 on: March 04, 2012, 05:43:12 PM »
I always thought that proper timing was when the distributor,s rotor was pointing at the number 1 cylinder. Your posts imply a  different position (around number 2 cylinder), is this correct ?

That phrase has been misunderstood for years - it means the rotor is to be pointed at the #1 wire tower in the cap; that's the only way the wires can be correctly indexed in the cap. The correct wire indexing in the cap is shown in the '69 Assembly Manual (UPC 6, sheet B9, View "A") and in the '69 Chassis Service Manual (page 6Y-27, item #6 - "Place distributor cap in position and check to see that rotor lines up with terminal for #1 spark plug"). The #1 wire tower in the cap is always in the next position clockwise from the adjusting window.
'69 Z/28
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