Hello,

I'm getting ready to install the 600cfm carb that my brother picked up for his car. I also had to buy a new timing gun to tune the engine with. (my favorite one died finally) As per a previous forum, we discussed timing, which we believed to be one of the major problems in the low end power band,... or should I say,... the lacking of low end power! As of right now,... it can't even light the tires, and the car takes off very sluggishly. This does lead into very powerful acceleration, but thats not until about 4000 RPM. Anyway, I am having a little trouble figuring out how to use the new gun I bought and how to properly time the vehicle. Its a Timing advance light. Its one of those guns that has a little dial with numbers on the back ranging from 0 to about 50 degrees. I tried timing it dialed in at 0 on my chevelle but I don't think I was too successful. Could some explain to me how to use this thing properly and also refresh my memory on the proper way of timing a car. I have a bad tendency of doing a guessing job when timing.

P.S. The engine is a 327 w/ 409 (?) Fuelie Heads, Rebuilt w/ 2500 miles on it, edelbrock 600cfm manual choke carb, edelbrock performer manifold, mallory unilite distributor (no vacuum), MSD Ignition, Headers,

Usually what I do is set the dial for how much advane (or retard) that I want, then pull the trigger and aim at the timing tab. When the line is right up with the zero I know I've hit my mark.

Have someone sit in the car and observe the tach.

With the vacuum advance disconnected rev the engine slowly.With the timing light hooked up observe when the timing stops advancing.Hold it there for a second.

Now ask the person watching the tach tell you what that rpm was.

Adjust your light to read between 36-38 maybe 40 degrees if that's how much total advance you want to run.

Have the person inside rev the engine to that same rpm point.
Point the timing light at the timing tab and move your distributor either forward or back so the light flashes when it is on zero.

Whatever you have your timing light set at, be it 36 or 40 degrees, that is how much total advance you should now have.

Hook your vacuum advance back up.
You might want to readjust your idle mixture screws now.

If it pings back the total timing down a couple of degrees at a time.If it keeps pinging and you are lower than 36 degrees disconnect your vacuum advance and leave it that way.Don't forget to plug your vacuum line.
Readjust your idle mixture screws and reset your timing again.

Once you have gotten used to reading where the timing stops coming in at you can easily set the timing by yourself, it's just easier to do it with someone helping for the first few times.

If your timing is still advancing when you are at 3200 rpm you should purchase an advance kit.Just install one of the lighter springs and then see where it stops advancing.
It should stop somewhere in the 2800-3200 rpm range for good performance.

As you can tell this is a trial and error process.

I dont " preset " the timing light, I just aim it and dial it up until I am lined up at 0 then read the dial.

I've never owned a dial-back gun, but doesn't it seem easier to check timimg w/a degreed balancer or a timing tape? I use a Sears regular timimg tape and shoot it at my balancer (which is marked all the way to 60*, even a 90* mark for setting valves I guess) and it shows where the timing is at. You can also see if the timing is stable and how smooth it advances. I don't know if the dial-back will do that for you.

Originally posted by Vince g:
I've never owned a dial-back gun, but doesn't it seem easier to check timimg w/a degreed balancer or a timing tape? I use a Sears regular timimg tape and shoot it at my balancer (which is marked all the way to 60*, even a 90* mark for setting valves I guess) and it shows where the timing is at. You can also see if the timing is stable and how smooth it advances. I don't know if the dial-back will do that for you. How many stock balancers do you know of that are degreed ? The dial back will be just as stable as a non dial back. You can use the dial back just like a non .. just leave the dial set on 0

Dan,
Hate to tell you at this point in time but ... MSD does not recommend using a "dial back" type light with thier ignition systems. The multiple sparks drive them crazy. I know of one $300 Snap-On light that read close to 20 degrees off when used on a MSD ignition system. Another racer buddy burnt pistons in an engine twice until he found out that his was also reading incorrectly.
I know there are some guys that swear they have used them but ... do they know for certain that they are correct ? I would stick to a non dial back type light on MSD ignition systems.

BLK64SS,

I'm aware that all damper aren't marked. Thats why I mentioned a $7 timing tape also.

While it's true that MSD doesn't recommend you to use a dial back light with their systems it seems to be a hit or miss situation.
Some are off and others aren't

Some are way off as stated.

I don't have any trouble timing my engine with advance timing light and plugs are perfect! I think it does depend on application. Of course a good comparison would be to check timing with both types of lights! I've use both without significant difference! :cool:

That is interesting on the dial back lights and the MSD, I didn't know that. I guess it would be OK to use the dial back with an MSD to check total timing at an rpm above where the MSD does not give off the multiple sparks. Ant thoughts?

It just snowed so and its 15*F out right now so I think that the project is pretty much on hold,... The carb I have on the car now I know is screwed up. Ill install the new one and then try timing it with the advance gun. If it still runs badly I guess Ill have to get another new gun. Thanks for the advice,... I would have wondered for a while if I was timing it right,... never knowing that it could be the gun conflicting.

Thanks,

Dan

Dan,

You must be in the warm part of the state.

Fred.

Originally posted by SS4speed:
Dan,

You must be in the warm part of the state.

Fred. Yea, Warm!

I must be crazy is more like it! As I look out my window all I can see is white,... Arizona is sounding pretty good right about now,... and I'm sure my Chevelle would love it too, (No more rust)