Dopey Question About Engine Timing

[Guest philedmonds]

I assume the cylinder closest to the front of my '49 B1FA Dodge is numbered #1. Is that correct?

Since the #6 cylinder fires 180 degrees after #1 and the crank turns over twice per cycle, I assume the timing can also be set using the #6 cylinder. Is this correct.

I had a little trouble with my timing light. I read that you need to use a 12 volt battery to power the timing light. It worked OK, but not great. I later found that you need to run a jumper from the frame of the truck to the negative clamp on the timing light. Can anyone shed light on this? Thanks and sorry about asking such elementary questions.

[grey beard]

Your assumptions are all correct about number one and six cylinders firing one turn apart. In other words, the crank does the same thing on both compression and exhaust strokes. What is different is the posirtion of the cam shaft and valve train on these strokes. You are right on the money!

Your 12 volt timing light will not power up wirth six volts. This is why you must use the 12 volt battery. Just hook your timing light power leads to the 12 volt battery terminals and forget about ground jumpers. The power for the light and the timing signal can come from two separate sources as long as they share a common ground. Just did this on my own truck yesrterday - worked fine. It is the only logical way to set timing on a 6 -volt vehicle. Older 6 volt lights were very dim and weak, and the xenon light that just used spark plug power was sorta' pathetic. If I had one I'd throw it away . . . JMHO

[TodFitch]

. . . The power for the light and the timing signal can come from two separate sources as long as they share a common ground. . .

I think it depends on the timing light. The one I have clips around the spark plug wire (inductive pick up I guess). Anyway, I don't need to have a common ground between the 12v battery running the timing light and the 6v car to have it work.

[billwillard]

You guys are right on but not making it clear for him. YOU MUST RUN A WIRE FROM - SIDE OF 12V BATT TO A GOOD GROUND ON THE CAR YOU ARE TIMING. TIMING LITE TO + AND - ON 12V BATT. I USE ONE WIRE OF MY JUMPER CABLES AND HOOK ONE END TO THE - SIDE OF 12V BATT AND THE OTHER END TO THE FRAM ON THE CAR IAM TIMING.

BILL

[Don Coatney]

the xenon light that just used spark plug power was sorta' pathetic. If I had one I'd throw it away . . . JMHO

Dave;

I have had this "spark" powered timing light for over 40 years. Used it several times and it still works the same as the day it was new. Crappy. However I have had it so long I will not toss it.

I think it depends on the timing light. The one I have clips around the spark plug wire (inductive pick up I guess). Anyway, I don't need to have a common ground between the 12v battery running the timing light and the 6v car to have it work.

Tod;

My new timing light also uses a clip around the plug wire and no ground is required.

YOU MUST RUN A WIRE FROM - SIDE OF 12V BATT TO A GOOD GROUND ON THE CAR YOU ARE TIMING. BILL

Bill;

It is not necessary to run a ground wire on all timing lights. Tod and I do not need to do so with the timing lights we have. How many leads (wires) does your timing light have? 3-4?

For a much brighter light on any type of timing light connect the high voltage lead to the coil wire as opposed to the number 1 plug wire. The light will then fire everytime the coil fires but you can easily see the timing mark and set the timing. Try it.

[Merle Coggins]

What kind of timimg lights are you guys using that need to have a common ground? Any timing light that I've ever used, aside from the inline ignition fired ones, use an inductive pickup to trigger the flash. You should be able to connect your power connections to a 12 volt source, the inductive pickup clamp to #1 plug wire (or #6 will give you the same results), and time away. No grounding jumper wires should be needed.

Merle

[Zeke1953]

I bought a self-powered timing light from these guys and it works great. Zeke

http://www.magnumforceracing.com/flaming_river_timing_light.asp

[Young Ed]

I just used a 12v one hooked to my 6v car without problem. It was kinda bright out so I through a thick blanket on the sunny side of the hood for some shade and it timed just fine. The connections were + and - on the battery and then on the #1 plug.

[bach4660]

on the timing, the inspection plug is over cylinder #6, so if you measure the height of the piston on the compression stroke then the rotor and points are on the 6th cylinder or basically the 2:00 position, right? I got myself confused as I am used to using cylinder #1 on the compression stroke and the rotor at 7:00

[greg g]

My 60's Craftsman works just fine on 6 V, thankyou..

[Guest philedmonds]

I had found both lock bolts on the distributor. I used a 12 volt light with a 12 volt battery and did run a jumper from the 12 volt negative battery terminal to the truck frame. I had marked the 0, the +10 and -10 timing marks with paint. I did use the #6 cylinder and had no trouble setting the timing correctly. thanks for all the input and assistance.