440 Timing....what is my timing reference point?????

[Dodge Don]

See picture below. When I'm timing the engine am I looking at the hole in the middle, the top of the tab or the bottom of the tab to see the timing degrees??

[Cooter]

I use a pen flashlight and shine the light sideways across the timing tab until I can read "0"...

If indeed it is the "hole" for "0", then one way will be BTDC and the other will be ATDC..
Then, I mark it with a marker for next time.

[flyinlow]

The hole should be 0. The top arrow is 10* ATDC, the bottom arrow is 18-20* BTC. Most of your marks on the damper will be under the stock timing tab and not visible.

Hi lite the zero mark on the damper, should have a slot. You will be able to see the front of the slot  in front of the tab. If you have a roll back timing light that's all you need to do. With a standard timing light it helps if you hi lite the front of the damper by the 30* and 40* marks. You base timing plus centrifugal will be between the 30 and 40 on most engines.

[Dodge Don]

The hole on the tab is marked as Zero.....at the bottom of the tab is says "BEFORE".

So when I'm timing the engine I should look at the hole (not the top of the tab) and that will tell me the degree I'm at?

[firefighter3931]

Hi Don, just responded to your PM. 

The hole in the middle of the tab is your reference point. The small scale (above & below the hole) is used when a stock style balancer only has a single timing mark. Your balancer has a 60 degree scale so whatever reading you're seeing at the hole (center of tab) is the degrees of timing advance. 

Clear as mud ? 


Ron

[Dodge Don]

Hi Don, just responded to your PM. 

The hole in the middle of the tab is your reference point. The small scale (above & below the hole) is used when a stock style balancer only has a single timing mark. Your balancer has a 60 degree scale so whatever reading you're seeing at the hole (center of tab) is the degrees of timing advance. 

Clear as mud ? 


Ron

Okay thanks Ron. All the info I read and videos I saw had a straight tab that pointed to the degree...I assumed that was the top of the tab and when I saw 30* base timing I got concerned that I had been hurting the engine with an insane amount of advance.

So based on this info.....this afternoon when I was checking my Base Timing at 900 RPM Idle the top of the tab was at 30*.

And I can see that the top of the tab is 12* from Zero (hole) to top of tab..........therefore when I thought my base timing was 30* (which seemed concerning to me) it was actually 18* if I had looked at the degree lined up with the Zero/hole mark.

[firefighter3931]

Yep, you are correct Don ; the actual timing is 18* BTDC and not 30* like you thought. 

When you get it fired up again allow it to warm up to operating temp with the vac advance disconnected and carb port blocked off and keep advancing it until the vacuum guage reaches max reading. This is what your engine is asking for in terms of base timing. After that it's just a matter of dialing in the mechanical advance to get you to 35* total. 

Ron

[Dodge Don]

Of course this "easy" exercise is for me...a disaster.

Okay. So I hooked up my vacuum gauge and hand advanced the distributor to the point of highest vacuum and RPM..then backed it off a tiny bit. So base timing was now around 21*-22*. Checked total timing and it was at 48*

Pulled out the distributor and found the mechanical advance setting was set full open at 28*. So using the curve keys I reset the mech. advance to 14*. Put the distributor back in and when I went to start it I got a backfire out of the exhaust...car won't start....it catches a bit but runs like shit and dies. Now my battery is dead.

I should have just left it at a shop.  I hate ignition or carb stuff.

Waiting for battery to charge before looking at it again.....any suggestions?
 


 

[Dodge Don]

I hand advanced the distributor and got it running...but now I've rotated the distributor a good 1/4" and it needs to advance further to get it running right but the distributor cannot rotate anymore as the vacuum advance pod is hitting the upper rad hose and one of the spark plugs is hitting the valve cover. The marking on the distributor base was exactly where it was when I removed it...did I install the dizzy wrong?

[flyinlow]

Picture might help. I just walked out to the garage and looked at two 440 Chargers with 15* and 24* base timing. Both vacuum advance units are pointing close to straight across the engine towards the PS pump if you use the vacuum hose nipple for the pointer. Neither comes near the radiator hose.

Any chance you pulled the drive gear up and it re indexed?

22* base is fine as long as the starter can crank it on a warm start.

What distributor are you using that has an adjustable advance plate?

[firefighter3931]

Ok, time to take a deap breath and start from scratch 

Get the motor up to tdc with #1 piston at the top of the bore. Next, advance the balancer 20* and install the distributor with the vac advance nipple pointing to the driver side inner fender....or put another way, have the vac pod paralell to the front of the engine.

Get the cap tower lined up with the rotor ; this is #1 and after that you just follow the firing order going counterclockwise. With the distributor in this position you will have fore/aft movement to make timing adjustments and your base timing will be 20* BTDC right from the get go 


Ron

[Dodge Don]

Could it be the reluctor wheel I had to remove? Or possibly the magnet got moved a bit during efforts to get at the lower plate where the mechanical advance was.

If you look at the picture to top hole on the reluctor had a roll pin....the one on the bottom did not.

[A383Wing]

the 2 holes for the roll pin are for big block & small blocks....the reluctor wheel is used for both...make sure you put it back in the way you took it out

[firefighter3931]

the 2 holes for the roll pin are for big block & small blocks....the reluctor wheel is used for both...make sure you put it back in the way you took it out

Mr Wing is correct....there are 2 positions to locate the reluctor wheel to the shaft and if you install it in the wrong position your distributor phasing will be way off. This would account for you being unable to set the base timing.

Quick way to check phasing : point the rotor to any tower on the cap and remove the cap and have a look at the reluctor to pickup orientation. If the reluctor is installed in the correct position the star will be facing directly at the pickup....they will be directly opposite each other.

If the star and pickup are not in line with each other then you have the reluctor in the wrong position and need to move it over and re-check phasing.


Ron

[A383Wing]

there is an arrow on the reluctor...you will need to put the wheel on the roll pin in the slot for the direction it goes...I think you have it in the "small block" hole

Bryan

[flyinlow]

There are two arrows, one pointing each way (isn't that convienent). The '73 FSM says align the arrow pointing counter clockwise (for BB) by the locator pin.   I checked mine and it is that way. On mine the locator pin is opposite the slot that locates the rotor. and that is where the CC arrow is. Sorry ,I can't see the pin in the picture.

[Dodge Don]

The pin is where the arrow notes.



How do I "point the rotor to any tower on the cap and remove the cap and have a look at the reluctor to pickup orientation"......how do you point the rotor without taking off the cap? Sorry do not understand this.

And "If the reluctor is installed in the correct position the star will be facing directly at the pickup....they will be directly opposite each other." What star? Facing each other yet opposite each other?

I'll try to look at the reluctor tomorrow....but failing that I'm just going to have it hauled away.

[flyinlow]

Your distributor appears to be set up like mine after looking at your last post.

If misery likes company, I have spent the last month replacing the starboard engine on a boat I don't want. 2 strokes suck, Yamaha sucks, boats suck.  Its been raining hear for 20 days , maybe it will rain for 20 more days ,flood the world and float away.

[firefighter3931]

Don, if you look at your pic, the star i'm talking about is the point on the reluctor wheel. These points are commonly referred to as stars and you have 8 of them....one for each cylinder.

Again, referencing your pic ; you can see that the star or point on the reluctor wheel is directly in line with the pickup. Put another way, the point is directly opposite the magnet. I don't know how else to say it

As for lining up the rotor on your cap ; just install the cap and make a mark on the distibutor body where any one of the 8 towers is located. When you remove the cap point the rotor to that mark. If the phasing is correct, the rotor will be lined up and so will the reluctor point (star) with the magnetic pickup. Both of these things have to be lined up simultaneously or the phasing will be off. 


Ron

[Dodge Don]

I tested the gap on the reluctor. It was larger than 0.14 which was my largest brass feeler gauge. I adjusted the gap to .008. I'll test it after lunch by setting the distributor back to where I tested/set my base timing and giving it a go 

[Dodge Don]

After gapping the reluctor I hand moved the distributor back to the position I had noted after setting my max base timing.....It fired right up. Made some tiny adjustments to base idle timing and lowered idle on carbs. Seems to be running okay. I'm waiting for an assistant to check my total timing and then give it a street test. Near as I can tell I have 20*-21* base timing right now.

Still no idea if this was a complete waste of time or not but if my total timing was high because the mechanical advance was set at 28* and there was little room for good base timing that was not good.

I started this to:
a) increase performance
b) lower engine temperature
c) increase vacuum to power brake booster

[flyinlow]

I started this to:
a) increase performance
b) lower engine temperature
c) increase vacuum to power brake booster

Optimum timing will help all of those.   

[firefighter3931]

Going inside the distributor was definately worthwhile....with 28* of mechanical you were running too much total timing for sure. 

With 20-21* at idle and now 14* of mechanical you should be in the 34-35* total range which is where it should be with your closed chamber RPM cylinder heads. 

The idle vacuum should have picked up and when you drive it the throttle response will be stronger. Too much timing will cause overheat issues....just like too little timing will. 
   
Nice work Don.....you did it ! 



Ron

[Dodge Don]

Took it out for a test drive. The engine seems to be running noticeably smoother while driving. However I noticed right away my low end torque is reduced...a lot. Doesn't bog but kind of lethargic when to step on it. On the flip side while I was driving down a long road at around 45 MPH I hammered it and it pulled like a freight train hauling ass. So I have lost some low end oomph. Not sure if this has anything to do with the vacuum advance being unhooked/blocked off.

At least it drives again. Unless I figure it out tomorrow I'll likely schedule it to go into the local performance car shop to have them figure it out and maybe put it on their chassis dyno.

It is currently at 23* base timing, 14* mechanical advance and 37* total. Vacuum advance blocked.

Just out of curiousity....blocking the distributor vacuum advance (which was connected to the center carb) doesn't affect the vacuum activation of the outboard carbs does it?

[flyinlow]

Ported Vacuum advance  only works when the throttle is open above idle and there is more than 10-14" of vacuum in the intake.depending on how the vacuum unit is set up. Never there at High power settings (low manifold vacuum).
Vacuum secondaries are opened by a strong vacuum in the primary bore venturi , like when a 440 is trying to wind up on the two primary bores. Plugging the advance unit should not effect the secondaries opening.

Don't want to reopen the great vacuum advance debate. My engine has a more energetic part throttle feel with about 6* vacuum advance. Seams to help the millage slightly.

Just out of curiosity , at what rpm is your total centrifugal advance in?