Vertex Mag. timing

[g935]

I’m curious. What do you use most often when timing a motor with a Vertex magneto, a timing light or “buz box?” I was on Don Zigs website and he stated that timing lights are not very accurate when used for timing a motor with a magneto. The article states that timing lights can be one degree late for every 1,000 rpms. With the buz box connected correctly, all you do is set the timing at the crank and then turn the magneto housing while holding the rotor until the box quits buzzing. That’s when the points open. I’m condensing this but that’s the basics. Seems quite simple. I’ve seen it done but I have never done it myself. Just curious.
Geoff

[Fiat48]

I use to buzz them but anymore I don't bother. I simply put them in as you described with the points just breaking. Then I follow up with a timing light. Generally I am within 2 degrees when I check with a light.
Still a lot of racers will buzz them only and not use a timing light at all.

[Moneypitt]

Unless you have carefully set the timing pointer to absolute TDC any readings you get are at best +/- 1 or 2 degrees. I find the timing light works fine and is only a reference point to tune from. Even with the pointer calibrated it is still a reference point. The difference between 36 and 37, or 37 and 38 degrees, or any target you're shooting for, is minimal in the big picture. As a reference point you can get back to where you were if tuning attempts are made, for better or for worse.....MP
PS: I would really think before holding the rotor while you turn the housing!!!!!!!

[Fiat48]

This is from Don Zigs site:
"Never rely totally on your timing light as your sole source for timing your motor. Timing lights are typically D.C. and magnetos generate A.C. They also emit E.M.I. (Electro Magnetic Interference). In general, timing lights with mags are one (1) degree late for every 1000 RPM of engine speed. For best results, use a timing buzzer. We sell them and you can see one at the bottom of our products page. "
I think the question is whether we believe that or not...and therfore do we set with timing light as a final belief or buzz box as the final belief the timing is right.

[Moneypitt]

Get it close and wring it's neck........Tune from there!..........:) MP

[Fiat48]

I dont want to stray from the original post the man has done but want to add something here.
One of my pet peeves has always been timing jumping around all over the place on these blown alcohol deals. It's not so bad with a vertex but pretty bad with a Super Mag.
The vertex is easier to turn and this is probably part of it. The Super mag is much harder to turn and has this plastic rubbery lockout device that flexes. I have even made solid aluminum lockouts for Super Mags which helped a bunch but the lockout tore out the pins pretty quickly.
I find large variations in the cam drive gear on some camshafts...making more lash between the cam gear and the distributor gear. Some are really sloppy and a lot of backlash.
When I went dry sump and no longer turning an oil pump off the mag I find the timing jumps around worse than ever. Evidently the oil pump was stabilizing things a bit.
MSD makes a larger OD distributor gears to take up some of this lash problem which would help. But MSD units are .500 I.D. while Vertex and Super Mag are .490 I.D. Cstraub69 is trying to get me an oversize gear for the .490 shaft to help solve some of the problem. I'll see I how much that helps it.

[fc-pilot]

I have seen timing lights off, as well as buzz boxes not work right. My big thing is to always use the same timing light so if it is off so many degrees, it is always the same. At least that way I have a constant to tune from. If the box says 36 and the light says 37, then I would not get too worried. Either way, I would always use the same equipment to check it (and use both to reference off of each other). Maybe I am just paranoid?
Paul

[billet racing 1]

How much would a crank trigger help this? Seems to me that would be the way to go.
Jerry

[g935]

I have seen timing lights off, as well as buzz boxes not work right. My big thing is to always use the same timing light so if it is off so many degrees, it is always the same. At least that way I have a constant to tune from. If the box says 36 and the light says 37, then I would not get too worried. Either way, I would always use the same equipment to check it (and use both to reference off of each other). Maybe I am just paranoid?
Paul
Good info. from all you guys, thanks.
Geoff

[gn7]

This is from Don Zigs site:
"Never rely totally on your timing light as your sole source for timing your motor. Timing lights are typically D.C. and magnetos generate A.C. They also emit E.M.I. (Electro Magnetic Interference). In general, timing lights with mags are one (1) degree late for every 1000 RPM of engine speed. For best results, use a timing buzzer. We sell them and you can see one at the bottom of our products page. "
I think the question is whether we believe that or not...and therfore do we set with timing light as a final belief or buzz box as the final belief the timing is right.
ac/ dc is the biggy, timing lights were never disigned to pick up ac fields unless it is a timing light for a mag. flaming river and others make em. also if you go to a dry sump the end play on the cam becomes way critical because now you don't have the oil pump to hold the cam towards the back. Roller cam plus dry sump= jumpy cam unless you use some thing to hold it like a button set perfectly

[Moneypitt]

How much would a crank trigger help this? Seems to me that would be the way to go.
Jerry
The whole idea of a Vertex is the KISS principle. "Keep It Simple Stupid", (no reference intended). The very idea of a killer ignition with ONE wire is what keeps me coming back. Not to mention the total lack of wear and tear on spark plugs. We actually ran the same 8 plugs for 6 racing seasons!! And they're still good to go............MP

[fc-pilot]

Ray, do you need a sponsor to buy you another set of plugs for the next six seasons?:D
Paul

[Moneypitt]

Ray, do you need a sponsor to buy you another set of plugs for the next six seasons?:D
Paul
Actually we got 2 sets last year and still have one set in the boxes. The long lasting set was broken when the motor flew apart and smacked one of them, but the other 7 are still OK !!!!!! We could use a stud girdle that will fit the new AFRs.........Ray

[Infomaniac]

Ohm meter or continuity tester works great if you don't have a buzz box.
Timed aircraft engine mags for years with my timing box. Doesnt buzz but has 2 lights that go off when the points open. (2 mags per engine)
Always thought it was done this way because the timing marks were only 2 inches behind the prop. :idea: :idea: LOL

[Fiat48]

I have old Ma bell tester. Phone company issue. Changes buzz tone when points open. Dont use it anymore...just eyeball.

[steve d]

Used to use a thin piece of cellulose between the points. Pulled tension on it.
Could feel it start to let go. How's that for some backyard tactics..........?l

[Roaddogg 4040]

Hey Paul... Moneyitt might not need a sponsor for this y8ear but Roaddogg sure could use the help!!!:D We still need Zommies, Spark Plugs, oil and MONEY are always welcome in the old guys shop. Just PM me and I will give you the address...:D :D :D
Steve

[gn7]

We could use a stud girdle that will fit the new AFRs.........Ray
Do they make stud gridles for anything and if so WHY

[Moneypitt]

Do they make stud gridles for anything and if so WHY
Is there a question here?.........Does who? and for what? and why?.......Huh?