Wanted for test: PV governer assembly

[GMP]

If anyone has one from a part out motor I would like to borrow it for a test. As you may know, fellow member blitz11, a pretty sharp guy, has developed his own CDI. Talking with him, we would like to test and plot the opening curve of a PV governer vs. RPM and see how it fits with the advance curve of the ignition maps. It will be spun up with a high speed motor, and will be returned undamaged. Contact me or blitz11, thank you.

 

[gasgasman]

Can you monitor the bike's PV actuator rod with a potentiometer?
I think you will get a better reading with the bell cranks etc hooked up.

 

[widebear]

Found one Blitz.

 

[GMP]

Girard,

Considering the setup blitz has, it will be easy to get very accurate RPM data, unlike trying to do it on the bike. I'll leave it up to him but I can see doing it with strobe tach and a scale in the background. Actual PV flap opening vs. governer travel can be determined later, but it seems like the linkage is linear.

 

[blitz11]

Yep, that was how i was going to do it.

We'll just run it from 500 RPM to 11,000 RPM, and we'll measure its extension as a function of RPM. I know RPM from the timing pulses for each motor and each pulley combination. I'll just spin the governor at a fixed speed, and measure its extension. We can draw the curve, and then develop the model for opening. I have the stock ignition curve (to 4000 RPM...i can't run the stock ignition backwards), so we can see if the break in the advance curve jibes with the break in the PV governor.

The breaks SHOULD be close. You don't want to run too much advance with too much compression as that's a recipe for pre-detonation.

blitz

 

[widebear]

The larger 2k3 ign rotar does not have a timing mark on it where as the smaller 2k2 does, the 2k3 as we all now being timed with and alignment insert.

Does anybody see a problem of me using the 2k2 timing mark as a referance, in as a value in percent of circumferance in relation to the crank key slot and then applying the same % value to the 2k3 for indexing.

 

[blitz11]

Knowing now how these things are timed, you're exactly right. Just put in your timing mark at the same degree (not distance as the radius is likely different) as the 2K2 timing mark is from one of the edge of the magnetic strip on the outer circumference of the rotor. The CDI times everything from the magnetic interaction with the pulsar. That is assuming, of course, that the CDIs are the same between 2k2 and 2k3. (I have no idea as to why they would be different.)

blitz

 

[widebear]

Somebody help this ignorant old guy with his poor grade ten math decades behind him.

Depite the radius differances of two different objects ,90 degrees between two points of a circle working from on centre equates to 25% of its total circ?, constant. I dont have a protractor to use I'm going bush legue here.

 

[blitz11]

Somebody help this ignorant old guy with his poor grade ten math decades behind him.

Depite the radius differances of two different objects ,90 degrees between two points of a circle working from on centre equates to 25% of its total circ?, constant. I dont have a protractor to use I'm going bush legue here.

Here's what I did.

ON the ignition which has the mark, take a tape measure, and measure the circumference of the OD. Then, measure the distance from the raised magnet used to trigger the ignition to the mark.

Compute that ratio / fraction.

Then, with the new ignition, measure the circumference with the tape measure. Multiply the ratio above by the new circumference, and that is the distance the new mark should be from the same spot on the magnetic surface.

As long as the ratios are the same, you're money. no protractor needed.

blitz

 

[widebear]

Sounds good. Shipped gov this morning,should have it next week.

 

[blitz11]

Sweet. Once we crack this nut, then I can work on my time machine which will give me those two extra hours per day to get stuff done. I've been meaning to get to the time machine, but I can't find the time.

 

[Neil E.]

Did the experiment ever take place?

 

[blitz11]

Greetings.

No, the experiment never took place. The governor showed up in the spring, and i was getting my butt kicked at work. I couldn't find the time to work the experiment, so the governor went back to widebear. I never even opened the package.

I was only able to ride three times this year. It's not been a good motorcycle year. Maybe next year will be better.

 

[Zman]

I agree with gasgasman in that the powervalve response to rpm should be measured as an assembly. The response curve of just the unloaded powervalve centrifugal drive unit will be different than the complete powervalve assembly. The load of the bell crank and linkage is likely to be relatively constant, but the pressure and resulting force of the exhaust gasses on the powervalve in the exhaust port is likely to be variable relative to RPM, engine size and engine load.

It is also my understanding that there are and have been differences in the spring rates and amounts of preload between engine sizes, years and bike models.

That being said, I do think the concept is a great idea. I just want to caution people that the results may not be directly or universally applicable.