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Distributor - timing

3K views 28 replies 11 participants last post by  stangtim22 
#1 ·
I sent my distributor to Dan and I will get it back tomorrow. I need to know how To place it back in the correct spot (timing).

I'm pretty sure I need to put cylinder 1 at TDC and match the rotor with cylinder 1 of the cap.

Without removing the valve covers how can I know if 1 is at TDC? Remove the spark plug? Would I need to get a bore scope?
 
#2 ·
Pull #1 spark plug. Have someone turn the engine over with a socket and breaker bar while you have your finger stuck in the hole. When you feel pressure building up, remove your finger and watch the balancer and keep turning until the marks line up. Stab in the dizzy with the rotor pointing at #1 tower. Viola.
 
#3 ·
No. Remove #1 plug. rotate the crank by hand until you feel compression on your thumb. It will then be on the compression stroke. Rotate crank until piston is at the top of its stroke, pressure will stop. It's pretty intuitive. Aim distributor vacuum canister towards front of car and position rotor just to the right of 1 on the cap. Install distributor. Should be pretty close. Start it and adjust as needed. If you do get it off by a toothe one way or the other, pull it out just enough to adjust and reinstall.

EDIT: Sorry Bart. Didn't mean to type over you.
 
#4 ·
Sometimes the oil pump shaft will not be lined up exactly like you need it to set the distributor all the way in. If this happens, use a 1/4" deep socket with an extension and turn the shaft enough to get the distributor to sit all the way down. It might take a few times to get it right.

Tim
 
#5 ·
In a perfect world, shouldn't the balancer be lined up on the timing pointer at TDC? Granted, its still a good idea to confirm TDC as Bart and the others have mentioned. If the pointer and balancer don't match up, I'd imagine you might have a hard time getting the timing right.
 
#9 ·
In a perfect world, the pointer would line up to whatever the initial timing should be set to and the rotor to #1 tower. That would require no other adjustment. The perfect world doesn't exist, however, and that's why the distributor rotates.
 
G
#11 ·
Take a small piece of toilet paper and push it slightly in the spark plug hole. Rotate the engine by hand . . when the paper pops out ( and it will ), you are on the compression stroke. TDC is right at the end of that, so move the engine until the pointer lines up with zero. It will be very close once the paper pops out.
 
#15 ·
I guess the bigger question is where is the ideal position of where the piston is when the cylinder fires and why is 6 degrees so significant and the standard for most of our cars?

This is class, and I'm taking notes. Sorry for all of the oddball questions...

:cheers:
 
#17 · (Edited)
Gasoline doesn't explode but burns. You have to light the fire early so that the fire has reached its' maximum strength when the piston is at TDC so that the pressure pushes the piston down at the correct time. If the fire reaches its' max before the piston reaches TDC the pressure tries to push the piston down before TDC and bad things happen.
The faster the RPM the sooner you have to start the fire. That's why the distributor has advance mechanisms. With the engine idling you only need to light the fire around 10* BTDC but at 6000 RPM you need to light it around 36* BTDC. There are some very scientific formulae to compute all this but that's the story in a nutshell.
 
#18 ·
If the OP had made note of the rotor position before he removed the distributor the distributor could be dropped back in using that orientation. Eliminating all of this cranking and toilet paper. That assumes the engine wasn't turned while the distributor was out. Dave R.
 
#21 ·
I have found that the toughest part is getting the vacuum canister lined up properly, especially if you use a steel vac. line. It seems to always take me many attempts to get it to aim right, especially once I get the timing where I want it. All good advice here, though!
 
#23 ·
so you didnt mark it before you took it out. live and learn. like said its will be good experience for you

fwiw any time I remove one i bring it around to #1 so there's no guess work.

then i just put a light mark on the housing and block for a reference to get it started up. then just time it from there
 
#24 ·
Pre-marking the distributor assumes it was in the right orientation in the first place.

Rotate the engine to TDC on the compression stroke.
Install the distributor so the rotor points at the LH hood hinge.
If the distributor does not drop all the way in (pretty normal for me), the rotor should point toward the LH wiper pivot.
To drop it the rest of the way down, remove the rotor, press down on the distributor, and "bump" the starter for a split second. It'll drop down.

To set the timing:
Return the engine to the TDC/compression position, but this time at your base timing, i.e., if you'll be looking for the stock 6°BTDC setting, put the crank there.
Rotate the distributor so the rotor is between #8 and #1 wire.
Connect a loose spark plug to the #1 wire, and ground the plug.
Turn the ignition on.
Rotate the distributor housing clockwise so the #1 wire passes the rotor.
When the plug sparks, stop rotating.

You have now dry-timed the engine, and it should be pretty close.

If flames burst out the carburetor when you try to start the engine, you got the TDC wrong, and it's 180° off.
Turn the distributor so the rotor is pointing away from the LH hood hinge, pull the distributor up, rotate to point toward the hinge, and reset the timing.
 
#25 ·
There will always be multiple ways to find TDC and reinstall a new distributor. Hopefully your plug wires are long enough to where you can follow any of the methods mentioned and not be too far off of where they were originally lined up to. If it really matters, #1 on the distributor can be any one that you choose, as long as you point the rotor to it when cylinder #1 is at TDC. From there, follow the firing order in a counter clockwise motion if you are looking at the distributor from the front of the car. My #1 on the distributor points to the drivers side shock tower.

Windsor (289, 302, 5.0, 5.0HO, 351) Firing Orders

289 1-5-4-2-6-3-7-8
302 (Pre-82) 1-5-4-2-6-3-7-8
5.0 1-5-4-2-6-3-7-8
5.0 HO 1-3-7-2-6-5-4-8
5.0 Truck 1-5-4-2-6-3-7-8
351 1-3-7-2-6-5-4-8

Cylinder numbering

Firewall
4 8
3 7
2 6
1 5
Front bumper

Credit: Ford Windsor (289, 302, 5.0, 5.0HO, 351) Firing Order & Cylinder numbers
 
#26 ·
If it really matters, #1 on the distributor can be any one that you choose, as long as you point the rotor to it when cylinder #1 is at TDC.
Theoretically true, of course, but if your installation doesn't match the Factory Service Manual, and you don't have total recall, photographic memory, or if you have a shop service the car for you, you are screwed.

Following the Factory Service Manual simplifies your life.
 
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#28 ·
Well, I'm a pretty simple guy. The last thing I need is oddball stuff to remember about my car. Even when making modifications, I try to make things "year correct". For example, when converting from drum to disc brakes, I use kits that are the correct configuration for that year Mustang. Granada brakes will stop any Mustang just fine, but then when the car needs servicing, to gotta play name-it-and-claim-it to buy parts.
 
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