[dataway]

So after reading a couple of threads where people were trying to figure out what their vacuum or mechanical advance was doing I thought I try to come up with a bit of a problem solver.

The "dial" screws to the point plate using the locations for the points. The pointer slips over the point cam .. should slide in above the cam on the narrower part and then slide down on the cam.

Could be used with the distributor installed ... but you'd have to either rotate the distributor to get the pointer to zero, or rotate the crank to get it to zero. Still considering whether I should "slot" the mounting points so the dial can be rotated to zero independent of the point plate, but I don't want to complicate things too much.

On the bench you'd want to wrap a hose or something around the base of the distributor including the gear, so they won't rotate independently. Otherwise things just kind of spin around.

So ... anyway, being attached to the point plate ... when you actuate the vacuum advance the DIAL will move indicating degrees of distributor advance, since the POINTER is attached to the point cam .. that will move when you spread the advance weights ... then the pointer will show potential total mech and vac advance, or either one individually. Won't show mech advance curve of course .. but if you were sorting the shafts, point cam plate and weights and vacuum cans it would show you the maximum and minimum advance figures, and advance based on vacuum level.

Couple more tweaks and it will be ready to go. I thought about making the scale show crank degrees ... but being double up ... it would be harder to read ... easy enough to double the readings I think.

[Schurkey]

I saw a plastic-protractor job something like that, years ago. Didn't pay much attention.

Yours seems better-built. Well done.

Production plans? I bet those things could be simplified some, and cut out of sheet-steel fairly easily. A water-jet or laser shop could use a toothed edge rather than drill marks to indicate degrees, and it'd be done in the same operation as cutting the main body out of the sheet.

[Shiny]

How timely for me! I got it done on the bench with less grace. Your tool would have made it easy. Nice idea. I expect you'll 3D print this, right? LOL!

[dataway]

Yep, those parts are 3d printed. I've got some holes to adjust, and I want to tighten up the pointer and it should be done. Shiny .. your thread is what inspired this project, but I didn't want to interrupt your thread since you were already having to absorb a lot of info

Schurkey ... being 3d printed ... the parts were done in one shot. Like the dial piece ... I just turn on the machine, load the file and let it print. I have to stop it once to change to the sliver color to print the marks, but that's it, no drilling, no machining, pick it up and use. What looks like drill marks are raised dots, and the lettering is raised, like you'd see on an old school plastic ruler. Takes a couple hours to print the parts .. but you can go watch TV while it works.

[Shiny]

Ahhh now I see you are printing in multiple colors! Wow. That's a great use for that trick!

As to your tool, I'm not sure what I would have paid for it, but definitely something!

I took Sun Tuned's advice and MEASURED, which is the true value of your tool. By measuring, I found my new advance unit was "out of spec" (added more advance than max spec). It was also more than recommended so I added an adjustable stop by flattening a brass tube, slotting it, and clamping it to the arm.

Here's motivation - at least an hour lost, if not more, because you didn't sell me your tool:

Used a wire as a pointer, as taught by Cliff
Marked needle position vs vacuum level on the Mityvac
Took an overhead photo
Superimposed a degree wheel on the image
Read the advance for each vacuum mark

[dataway]

Hehe, you used special effects to do the same thing

Mine however ... will add the mechanical advance to the total if you want, and or measure the mechanical advance too.

I may have to make my first purpose made YouTube video to show it at work, it's pretty cool. AND ... it's 3d printed ... which is like a STP sticker on a car, it makes it's better

[242177P]

Another pointer (that takes the place of the rotor) would let you see how many degrees the mechanical limit allows. Raising the degree wheel might be useful, otherwise it'll need an enormous fang.

[242177P]

Disregard. Just realized it's on the cam already.

[dataway]

242177P .. as I was mulling this over in my head before drawing it up I was thinking the same thing, how much a pain it would be because some kind of rotor pointer would be required. I was very excited when I realized not only was it not needed, that the pointer on the cam would also add the two components together.

Just installed it on a 68 distributor, works great. Maxed out the vacuum can with a pump, left it on, then spread the weights out to their max position. Mechanical advance read spot on (12 degrees on a 524 cam), MS 201 15 can only got 10 degrees at the dist .. I think it's supposed to be 15. Not even enough slot for it to move 15 at the dist.

I'm calling this project a done deal, going to post the files to Thingiverse.

I'm a bit confused though .. a very commonly quoted article states that the can markings like MS 201 15 refers to 15 degrees of dist advance, and that all manuals, catalogs etc always refer to dist. advance ... yet, the mechanical advance plate like the 524 for sure refers to crank degrees. This confusion though doesn't effect the design of this project ... dist. degrees are dist. degrees.

[Shiny]

Being currently immersed in learning about distributor and carb tuning and digesting lots of guidance, I appreciate your ideas.

Your tool would have saved some effort for me, both for setting max mechanical and for the vac advance unit. OTH, approaching it differently helped me understand the mechanisms and adjustments.

More importantly to me, and in line with others' guidance, your tool keeps focus on the need to MEASURE and not assume.

[dataway]

I'm going to use it to test a few vacuum cans I have to get a feel for the ... "what they are doing, compared to what they are labeled" sort of thing.

Then probably just throw it in my "ignition box" to be forgotten for years until I build another distributor

[Kenth]

Originally Posted by dataway

MS 201 15 can only got 10 degrees at the dist .. I think it's supposed to be 15. Not even enough slot for it to move 15 at the dist.
I'm a bit confused though .. a very commonly quoted article states that the can markings like MS 201 15 refers to 15 degrees of dist advance, and that all manuals, catalogs etc always refer to dist. advance ... yet, the mechanical advance plate like the 524 for sure refers to crank degrees. This confusion though doesn't effect the design of this project ... dist. degrees are dist. degrees.

FYI, Vacuum unit 1116201 starts at 7-9 in/hg, have max 8° Distributor degrees Plus or Minus 1° at 15-16 in/hg according to Delco Bulletin 1D-187 dated 1-1-73.
And, stampings on Delco vacuum unit arms are crank degees.

HTH

Nice tools, BTW.

[dataway]

Thanks Kenth .. that's far closer to what I was seeing than 15 dist. degrees. It was making an absolute max of 10 dist. degrees at about 22", and right at about 7.5 degrees at 16-18" .

I re-read the article, and he does not say that part markings are in dist. degrees, he says that shop manuals, spec sheets etc. will specify dist. degrees and not crank degrees. So I was mistaken.

So typically the three digits used in a part like MS 201 15 are the last three digits of the OEM part number?

By the way ... anyone interested in any of the 3d files I create, on the various forum topics, they can be found by searching for "odataway" on Thingiverse.com.