From Lars' paper on performance timing.
"If you’re using an adjustable timing light, set the light to 36 degrees advanced. Now rev the engine just a little while observing the timing marks with the light. It shouldn’t take much rpm to peg out the advance without the springs installed. With an adjustable light set at 36 degrees, align the stock timing marks with “0” when the timing is “pegged out.” With the non-adjustable light, align your new 36-degree mark with “0.” Rev the engine a little to make sure the timing will not advance any further. "

1. Can someone explain the bolded section above to me. what am I aligning to "0" and how do I do this?

2. If I have the ballancer at the 8* BTDC mark is this 8 degrees of initial timing?

3. I think I read that my MSD distributor VAC advance is good for aditional 12* If I set initial and mechanical for 36* all in by 2800 wouldn't VAC add an additional 12* bumping me up to 48*

Please bare with me. More questions to come on this it confuses the crap out of me.

 

BlackRat........... here you go.

If you just had a normal timing light (w/o any advance adjustments), then at idle (650-700rpm), with any vac lines pluged to the distributor, your line on the balancer should show even to the 8degree mark on your timing cover when the light strobes. So with that you are 8degrees initial. (So if you increase your rpms with everything on, the line would continue to move upwards w/rpm, and, if you had a degree mark for 36 you'd stobe there at about 3000rpms...)

If you have a timing light with an advance dial, if that is set to 36, what that means is when you have your engine at 3000rpms (lets say) the timing mark on your balancer would line up with the zero degree mark on the timing case cover indicator. (it would "appear" as if you had zero degrees of advance, but not really).

So its "nice" to start with the timing light at zero so you can see your real initial (and I say that because you often hear folks complain of running a tad hot).............. then once that is set you can turn the light to 36degrees and see if your internals for the distributor are hitting "X" degrees of advance at "Y" rpms. Some want it all in by 2800, some 3000........etc. (and im referencing a MSD ProBillet w/o vac advance using their bushings to control max advance, and spring/combinations to control how fast it increases)

 

Thanks kaamacat! Let me see if i have this straight. I will be using a digital light so I want to set it to 36*. I am starting the car with the distributor installed at 8* initial. Using this method I would actually be seeing 44* when the light strobes because I started at 8* instead of 0*. In this case I would dial back the light to 28* taking into account the intial 8* making my actual 36* degrees when it strobes even though I am set to 28* on the light itself?

I have a headache!

Thanks
Wade

 

You just gave me a headach----dial in 36 on your light --set timing mark to 0 at around 3000 by rotating dist.

 

Bulls eye! I think. So regardles of the fact that I brought the motor to 8*BTDC and installed the distributor. I will rotate the distributor while the car is running until the mark on the tab and the mark on the balancer line up to "0" that will be my 36*? I know I am sorry I am probably making this harder than what it really is. I develop software for a living you would think i could figure this out!!!

Thanks
wade

 

Yes I think you have it now.Trust your timing light it sorta takes over by use of electronics and makes it easier.Vacumn off while setting but think you understood that.Good Luck---on that 3000 just rev up and back down you dont have to stay there.

 

The dialback on my timing light won't work with my MSD setup. It jumps all over the place.

 

Thats not good--Blackrat you might have to use the measure down method -Lars has the formula for that---

 

"Supposedly" This light will work at least that is what I was told and am hoping for. If not your right i will have to go with Lars' method.





EQU-3568
Brand: Equus
Product Line: Equus Products Digital Timing Lights
Power Supply: 12 V DC
Works on Points Ignition: Yes
Works on Electronic Ignition: Yes
Works on Computer Controlled Ignition: Yes
Works on DIS Ignitions: No
Advance Analog Dial Included: No
LCD Readout: Yes
Timing Light Material: Plastic
Timing Light Finish: Black
Backlit: No
Inductive Pickup Included: Yes
Dual Display Included: Yes
Displays Advance Readout: Yes
Displays Dwell Reading: No
Displays Tachometer Reading: Yes
Displays Volt Reading: No
Quantity: Sold individually.

Timing Light, Digital, LCD Readout, ABS Housing, Swivel Head, Xenon Bulb, Detachable Leads, Each

 

Mine jumps a little with the MSD (about 2 -4 deg) but we are talking a street ride here so I get it to where 0 is pretty much in the middle and call it good.

BTW you might want to research timing for a modern combution chamber headed BB, 36 is pretty good for an old design comb headed SB.

 

Lars updated his timing sheet slightly. Note he suggests leaving one spring on instead of removing both. You can email him for the updated sheet.
+++++++++++++++++
Remove your distributor cap and rotor. If you have a points-style distributor with the stock, factory, heavy springs in place, remove one of the springs.

Disconnect the vacuum advance. Install the rotor and cap. Loosen the distributor hold-down clamp bolt just enough so that the distributor can by turned, yet leave it snug enough that the distributor will hold its position.

Start the engine. If you’re using an adjustable timing light, set the light to 36 degrees advanced. Now rev the engine while observing the timing marks with the light. You will notice that the stock line on the balancer will move up towards the timing plate as rpm increases. Continue to increase rpm until the line does not move any further (centrifugal advance is “pegged out”). Once the timing is “pegged out,” the line on the balancer should line up with the “0” mark on the timing tab. Rotate the distributor to achieve this.

If you’re using a non-adjustable light, perform the same process, but align your new 36-degree mark with “0” mark on the timing tab.

Shut it down.

Pop the cap and rotor and re-install the spring, if you removed it. Put everything back together, but leave the vacuum disconnected. Start it up. For future reference, make a note of the timing setting at idle. This is your new curb idle timing spec. Now give the engine a few quick rev’s past 3,000 rpm and verify that the full timing (36 degrees) is coming in. If it’s not, you need to change to a softer set of springs until you get full 36-degree advance before 3000 rpm. (NOTE: A stock set of springs will often not allow full centrifugal advance to come in before redline rpm. If you have heavy stock springs installed, don’t rev the engine beyond its limits to try to force full advance in.) I suggest obtaining Mr. Gasket kit part number 927 or 928: Use the gold springs on HEI systems. For points-style systems, use one black spring and one silver spring – these springs will get your total timing all in by 2500-2800 rpm, providing very good throttle response and power. The black & silver spring combo can also be used on MSD distributors if you widen out the spring hook ends.

Hook up the vacuum. Re-set your idle speed and idle mixtures if necessary to lower the idle speed. Now do a road test.

The 36-degree 2500 rpm advance curve is optimum for performance, but may require premium fuel. Lug the car around, and punch the throttle at low rpm while listening for detonation (“engine knock”). If you’re getting any audible knock, you MUST retard the timing. Retard the timing in 2-degree increments until engine knock stops. Engine knock will seriously damage engine components if not corrected. If you get no knock, you may see slightly improved performance at 38 degrees total timing. This is particularly true if you’re running at high altitude.

If you have no engine knock under acceleration, but the car “chugs” or “jerks” at cruising speed (light throttle application), you are getting too much vacuum advance on top of the mechanical advance. You may need to change out the vacuum advance diaphragm with a unit producing no more than 16 degrees of vacuum advance. See my paper on “Vacuum Advance Control Units Facts and Specs” for more info on this.

Your timing is now set for best possible performance. Make note of the new setting, and use this for your future tune-up work.

Lars’ Suggested Timing Specs for GM V8 Performance Applications:

• 36 degrees total timing (vacuum advance hose disconnected), all “in” by 2500 rpm
• 18 degrees initial timing at idle (vacuum advance hose disconnected). Note that it may not be possible to achieve the 18-degree initial spec with the 36-degree total without modifying the distributor advance stop system. It is more important to achieve the 36 total than to hit an exact 18 initial. However, if your initial timing is very low (below 12 degrees) with the 36 total, it is important that you repair or modify your distributor in order to achieve correct engine performance
• 16 degree vacuum advance control unit with a pull-in spec that allows the full range of vacuum advance to be pulled in at the engine’s idle manifold vacuum level. Connect to manifold vacuum for most applications (this will allow the engine to idle with actual timing at idle of 34 degrees).

 

BlackRat,

I've got that light and am running the MSD performance module in my HEI dist and it works fine. Don't know about any of the other MSD setups.

 

Its almost a 2 man job Wade. You need to get the RPMS up to around 3000, this lets the centrifugal advance do its job. No vaccum attached to dizzy at this point. Your light preset at 36, should show 0 degrees when you point it at the timing pointer. If not, turn the distributor until you get 0 degrees on the timing pointer. This will have you set at 36 mechanical advance.



When you connect the vaccum advance, your timing will increase even more which is okay. Baseline with motor idling will be whatever it turns out to be 8, 10, 11, etc... 36 degrees at around 3000 is supposed to be the sweet spot by Lars Paper. That is where I set mine.

Hope I did not cloud the issue for you.

 

I'd like to jump in with a question here that has me totally confused. In regards to the springs, it has been mentioned to change the springs to get 36° advance for 2500-3000 rpm. There is one spring per weight in my HEI distributor. I have read numerous times to use use two different springs to get the proper advance. Does this mean to actually use two springs per weight (2 springs x 2 weights = 4 springs total) or two different springs on the weights ( one black on one weight and one gold on the other weight for example). This has really confused me and hopefully someone can clear it up. Thanks!



Jay

 

Blackrat...I have the std light and it also works with my MSD unit.

 

LABulldog..........What that means is......in your kit you would have probably gotten 3 "pairs" of different colored (and thickness) springs).
Heavy Silver, Light Blue, Light Silver. So you would always only use (2), but you may have one silver and one blue............

On the back of my MSD distributor box its showing If I use 2-Silver (heavy) springs my full advance wont take place until about 5300rpm. If I use 2-Blue(light) get my full advance at 3500rpms............ If I use 1-Silver(heavy) and 1-Blue(light) its 4500rpms. (and thats also based on what "advance stop bushing" I install UNDERNEATH weight assembly.

So think of it as if you use (2) of the lightest springs your full advance will be VERY early in the RPM range......probably 2200-2400........ if you use two of the heavies springs your gonna wait until 5500 or so for full. (so you mix to go either way).

Here is the RATE OF ADVANCE from SLOWEST to FASTEST.
2-Heavy Silver (Slowest)
1-Heavy Silver & 1-Light Blue
1-Heavy Silver & 1-Light Silver
2-Light Blue
1-Light Silver & 1-Light Blue
2-Light Silver (fastest)


Hope this helps..................................

 

Thanks for all the information guys. I opened up my timing light tonight and read those directions which were pretty basic. I think what is going to have to happen is I am going to have to actually try it and then apply all the info you guys have given me. The light instructions actually confused me. It says to 0 out the display and nothing about presetting the amount of advance. So when the motor starts I am goin to get a base line reading by rotating the distributor till the timing marks line up to 0 on the balancer and pointer. Then the strobe should ignite every revolution on the 0 mark. Does the light calculate the degrees of advance somehow and display it? sorry I know some of you are banging your head against the monitor right now.

Wade

 

You could also measure and draw a new line on your balancer and just use your timing light in old fashioned mode. You have a factory line on the balancer now that is 0 degrees advanced at TDC. Measure, calculate and draw a new line at 36 degrees advanced on your balancer.
Now rev your engine to 3000 rpm. You should be able to see all 36 degrees of advance. If you do not, then rotate your distributor to give yourself more initial advance. This way you can increase your intitial advance until you get enough initial to achieve 36 total at 3000rpm.
Now that you have 36 degrees total, you can play with the weights and springs until you get it to come in at 2500 or where ever it works best.

 

Wade thats the other way to measure the existing total timing.Rev it up look at mark and dial the mark on the balancer back to 0 on scale.Now idle down and look at scale on timing light that will be the existing total timing keep moving dist. until reading on timing light scale is 36---both ways obtain same results.

 

Here's a related question....I have a non adjustable light and was gonna pick up a timing tape at the local speed shop today...ahhh, I start the tape (zero) at the notch and run it counter clockwise on the balancer....yes?