Reading an Advance timing light.
 

This is probably elementary to most of you, but I think I`m not getting any advance from my distributor and wanted to be sure I`m using my light correctly.
I have a Delco Voyager distributor. I set my timing at 10* BTDC at idle (800 rpm). As I increase rpm`s the timing mark doesn`t seem to move or barely at all. By 1500 rpm it doesn`t move anymore and it reads 16* BTDC. I am lining up the deep line on my balancer with the tab from the timing cover and turning the dial on my timing light. At 3000 rpm the marks line up and the dial on my light is set at 16*. My timing won`t go past 16* no matter the rpm. I think I have a bad distributor. ???
Am I following the correct precedure to time a Voyager distributor?
All suggestions appreciated.
THANKS!!!

I'm not familiar with this system, but is it computer controlled? I believe that you need to unplug the input to the distributor and then set it to a base timing level. What happens is that the computer trys to override the distributor throwing your timing off.

Didn't it come with a Tbolt ignition originally? I'm also not familiar with the Delco. What type of distributor is it? Mechanical, points, computer controlled, does it have a vacuum advance?
Gary

The Delco Voyager is the Delco distributor that was designed for computer-controlled autos. It is called Voyager when marketed to the marine industry. The computer controls advance, not the distributor. However, if the computer failed, the distributor has a built in advance curve (called the "limp home mode"). The built in curve is pretty good for a hi-perf marine engines. 11*at 700rpm, 22* in by 2800rpm

To time the Voyager, you have to plug a special wiring harness into the empty terminal and ground the alligator clip. AC Delco part no. 10486133

Hope that helps.

I am running this on a non-computer engine.
I read in Dennis Moore`s book about this distributor and got the Delco number for the timing plug-in. After several attempts I found out that it has been discontinued and no longer made. I studied the photos in the book and tried to make my own test plug from a pigtail that fits in the socket. Using my homemade plug-in didn`t seem to lock out my timing either.
I am ready to order an MSD distributor, but hope to find a less expensive solution to my dilema...

I don't know anything about your distributor but, when you say it has a pretty good curve for a marine engine are you saying that total advance is 22*? That is not enough. You need 34-36* to get good performance out of a BBC. If you are going to buy a new distributor take a look at DUI. http://www.performancedistributors.com/marinedui.htm

They are supposed to be very good and at a good price for an entire ignition system.

The ignition module has a built in advance curve that is all in by 2800 rpm. Full advance is 22*, add that to your initial timing, of say 12*, now you have 34* of total timing.
I just tried something: I said forget about initial timing, let`s try setting total timing. I now have timing at 34* @ 2800. It starts good, has a nice idle and good response. I will lake test Saturday....
With my distributor twisted around to give me 34* total, it now shows 30* @ 1200. Figure that one out. It does start great, every time.

I asked a question kind of similar to this last week and one response that I reccived was that advance timing lights are junk, and do not use them.:confused:

I have a Sears model advance timing light and a degreed ballancer on my hot rod vette and the ballancer and the light are identical. I trust mine. I was told the same thing by a old timer engine builder, resistance to change is what I think it is....

Brian

DonMan, sound like you have your problem solved. If you do find the need to get a new distributor system, go on ebay and look for a Merc Thunderbolt IV. They are usually some listed. And every once in a while, a TB V.

Good luck

Just to be sure, why don't you also check the timing at 3000 and 3500. 34* at 3500 and let the initial fall where it wants.

I was playing with the distributor and the engine sounded best at 34*. I also set the timing without the light and just used a vacuum gauge at idle. I twisted the distributor around until I saw the highest reading on the vacuum gauge. Then I rechecked timing with light and it was showing 34* while fully advanced. I`m leaving it alone until I can hit the water tomorrow and do some real-world testing.

DonMan, 34* should put you right in the ballpark. You won't hurt the engine and it should perform well enough at that setting. Do not rely on where the engine sounds best or the vacuum reading at idle. Those methods of timing an engine are for people that don't understand what a timing light is for. Trust me on this one. And, as 220BR says, you should check the timing at 3500 as well to be sure that full advance is achieved at 2800 rpms.

THRILLSEEKER, A good advance timing light is necessary to check the total advance on most engines. The reason you cannot use a standard timing light to do this is because the degree marks on the timing pointer do no go high enough. Most BBC pointers only go to 16*. It is a good idea to check the accuracy of the advance timing light, though. You can do that by setting it to zero and using it to see what the degree of advance is at idle by reading the marks on the pointer. Then adjust the advance light to that same degree reading. If it is accurate the timing mark on the balancer will line up with zero on the pointer.

A good digital model that has a good price is the OTC 3368. It has a very sensitive digital tachometer built in and is available for less than $150.00. Most auto parts stores can order them or most mobile tool distributors can get them, also.