Advance timing light..How to's required

[Whaler]

hello guys

I have had the luck of having a friend drop off his snap-on digital advance timing light. I have figured out to use it. I really need to know how to time my car by using it in a nutshell

Heres my situation.

Car is static timed now for 14 degrees. I have set up my MSD using the default blue advance stop bushing ( gives 21 degrees advance) Chose a light blue and a light silver spring as i wanted it all in by 3000 rpm

Today I am at the "let's finally see where the heck this thing is" stage since my FE break-in 2 nights ago.

So as far as I know, you hit the adj button/s to bring the mark to zeroon the damper. In my case at an idle, I have my display reading 14 and the 0 mark on the damper is bang on my timing pointer.

There are 2 adjust buttons to bring the degrees up or down.
At 900-1000 idle, I have 14 on my indicator.
At 15-1600 I can line up my zero with about 24 to 26 on the digital
So heres the catch I have reved it again with a bit more speed and it lines up at about 24 to 26 degrees with only 1500-1600 rpm....Is this the regular curve rate for these springs or does it seem a tad fast.
Do I need to go for some stiffer springs or what? Seems to be coming in early .. But hell what do I know I am new on this stuff

Also I should be seeing a total of 21 advance from the stop, plus 14 from static....giving a total of 35.
Should I forget about all this now and just see what rpm I have for 35 or so?? I had hoped its all in by 3000 rpm based on my spring choice.

Looking forward to some tutoring here.

What I have picked up
Never less than 10 or more than 20 static ( initial) advance
Ford that like 34-38 total with iron heads may like lots less with alumimun heads.
Where/how does one end up determining what is ideal initial timing and also what their idle rpm should be set at. At present I am about 900-1000 rpm warm and with 14 initial. It starts ok.
I have the edelbrock RPM package including their cam.....its a little lopy. What are you guys with these cams idling at??

Its a little fat too....still have the carb to do next. Initially I just gave it the basic 1 1/2 turns to each idle mix screw. Ballpark.
Holley 850 Mech Sec. Double pumper.
Haven't tried looking at idle vacuum settings yet. Not until I have the idle and timing set up.

It isn't flooding so the floats are not too high.

Tim

[ted]

That was awful lengthy. To my point, those dial adjust timing lights don't always read accurate. This is due to the various electronics in them and that knob that is supposedly scaled correctly to that decal. Even my dyno shop is aware of this and instead of using the shop's dial-adjust timing light, recommends to their customers that they bring with them a conventional timing light. I've solved customers problems with their engines by finding that their timing lights were automatically putting more timing into their engines than what they thought they had.

I haven't looked at an MSD instruction sheet lately, but they use to specify what kind of timing light to use and those "total" reading lights were not on the list. If you're using an MSD box, then you also need to back up the timing at least an additional 2° to compensate for the extra burn time in the spark.

One suitable procedure for total timing is to rev the engine until all the timing is in (mark has quit moving) and read the total amount of timing either on the damper or timing tag (depends what motor you're working on). For all my race engines, I recurve the distributors so that all the timing is in by 3000 rpm. This works well for my foot brake car that I launch at 3200 rpm. A timing tape works well on the damper providing it's for the correct diameter. It's also easy enough to put the appropriate marks on the damper when it's off and just use the "0" on the timing pointer.

If you're still intent on using that timing light, then check your total timing again using a timing light recommended by MSD or some form of conventional light. I haven't seen an issue with inductive timing lights versus those that just hook up in parallel.

I hope this helps.

[mr0077]

Tim, be sure the dial-back timing light isn't getting confused by the multiple spark the MSD generates...FWIW, I had to give up on a "dial-back" timing light...I bought one from Sears but took it back for a regular one, 'cause it wouldn't work on my MSD (MSD also told me that they wouldn't work, although some here had no problems with them). I marked a 36 degree mark on the damper and set the total advance there, then read the timing at idle for future reference.
Your advance to 1500-1600 RPM sounds like what you'd expect from the springs you've got in it, but either the advance is getting limited or the light isn't working at higher RPM. Try it with a regular light and see if it continues to advance between 1600 and 2500 RPM. If it does, it is probably the light; if not, something's limiting the advance.

[Whaler]

Ted
The light I have was a digital that will read tach and advance. Its simply an up/down or inc/dec . Its a Snap-on and its even got calibration tags hanging off of it when it was serviced.

I do have a snap-on inductance light as well also a loaned from another mechanic. ( Bluepoint)

Thanks for the heads up on accuracy. Worse comes to worse, I can verify one against the other....and if need be look for a third.

Yeah that was a lengthy post....sorry> I don't mean to be whenI first start out.


007
Thanks as well. I will look into the compatibility of this light with the advance light. Heck, I don't mind using the std inductance light. Used to those lights. Funny thing now that you mention the multiple spark characteristic of MSD. When the RPM function of this fancy light is called upon its all over the place, give or take 100 to 200. Not steady ( reminds me of using an analog meter and then going to a digital voltmeter) One has resolution they are not used to seeing. Analogs tend to smooth out these signals.

Will try the other light
Tim

[Excaliber]

,,,,,never did like those fancy lights. A good cheap induction light has served me well for many years.

14 static timing is where the curve starts. If you read 21, the motor bumperd it up 7 (14+7=21). 21 at 1600 rpm sounds about right to me.

Ernie

[zimmy]

MSD says to not use an electronic light as it will read wrong due to the multiple signals and the electronic noise. Use a cheap standard light. Should be okay . It worked for me.

[RallySnake]

Tim,

You did not mention a vacuum advance. If your MSD distributor has a vacuum advance, you must disconnected it and plug the vacuum hose.

My adjustable timing light doesn't work with the MSD either. I bought a Proform harmonic balancer cover. It's nice and chrome and has timing marks all around it. Now, I lock the light on static and I can set the idle timing about 16, then make sure the maximum doesn't go over 36. I used the springs to advance the timing all in by 2500 rpm and the 20 degree total advance ring.

One other note. I had touble getting the engine to idle under 1000 rpm with the Edlebrock RPM parts until I installed Rhodes lifters. These really helped the idle and low rpm power.

Paul

[Whaler]

Hi Paul

My MSD has no vac advance.

Its a funny thing, as you may have read I have access to both lights right now. So after all I have read and even what a tech said I checked the static at 14 for both lights and they agree. Both see that which is good.
I then ran it up to 35 deg on the advance light scale and it showed the line on the zero mark on the damper. Quickly hit the rpm button and it was 2900-2950
I have since marked 34-36 on the damper and verified it with the inductance light. Crappy thing is this sure is no one man job with the old light. Try and read rpms off the dash while you watch the damper?? LOL

My damper is marked of in 2 deg increments up to 50 total


BTW I had an e-mail response from the Edelbrock tech asking hm about idle and timing.

Hello Tech

I have the RPM cam with the rest of the package on a 428
I am wondering where the final idle should be set at. Or how do i determine where this car should idle??


"I would set the idle to around 750-850 RPM."

What is too low or too high??

"Anything over 1000 RPM would be to high.
Also timing around 12-14 degrees BTDC with a total of 34-36 all in @ 3000 RPM."

It has the heads and intake from the RPM package as well.
68-428 in a cobra kitcar...5 spd trans. 2400 lbs
I am using a holley 850 cfm mech sec. carb, not the edelbrock carb

FYI Also when I nailed down the timing yesterday, I hooked up my vac gage. At about 1000rpm, I see 14 " Vac. As it idles down, it gets to about 11 or 12" My powervalve is a baseline 6.5" so I think I have the buffer there

Tim

[RallySnake]

Tim,

Sounds like you're in the ball park. I would try to adjust the carb now with a vacuum gauge and see how it runs. Keep an eye on the color of the inside of the sidepipe. You want it to be a light grey. Black is too rich and white is too late, you've already burned some valves!

The question now is, how does it drive?

Paul

[SCOBRAC]

I got a fabulous digital timing light that works really well at kragen (kragen, schucks, checker) It was about $120. It allows you to set the idle off the built in tach. From there verify lead, about 8-12 degrees btc.. (FE)

From there use what you think you know about how your particular engine runs to dial in the distributor curve.. Follow the MSD guidelines for springs and opening rates. I went with a light spring (silver) and a med. spring (blue). I limited my total centrifigul advance to 20 or 21 degrees, getting all of it "in" by about 2600.. That gets you to 32-33 degrees total at 2600. You will want to check it at idle, 1600, 2200 and 2600. It should pretty much match the curves in the MSD guidelines.

The advance light allows you to check the various points along the way.. Dial in where you think you want the timing to be.. you won't see the light until you get close to the RPMs to about where they should be at a given point.

Take a drive.. Mostly it will "feel" right or it won't. If it's pinging at all dial it back a little or increase the spring rate to two blue springs.. If it isn't pinging perhaps try the lighter spring combo As light as these cars you may get away with the lighter springs.