ESE's works engine tuner

[TZ350]

Yep I have got do something else, I know, I will take some more of those yummy meds.

[Pumba]

Pain killers, what a magical fruit

[F5 Dave]

. . .

The forces generated by the reciprocating mass increases linearly as a function of the rate of reciprocating.

The force generated by the rotating mass increases as a square of the rate of rotating.
. . .

Fuck. Thanks Mike, now I have learnt something. That's all you needed to have said, something that I hadn't thought of but explains the change in amplitude with relation to the change of frequency. Makes sense but just hadn't bothered to think about it.

Then the frame acts as a damping cct as does the mass of the engine.

[TZ350]

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F5 Dave, your comments and Speedpro's contribution add to this. Many thanks.

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[Yow Ling]

OK all of this makes sense, however there is one bit I dont quite get. when weighing the reciprocating mass when it is still attached to the crank you will only weight a percentage of the rod. this is like weighing the back wheels of a truck and saying it weighs X tonne. shouldnt you have to weigh the rod and piston seperate from the crank. I think you will be out by more than half the weight of the rod

[TZ350]

when weighing the reciprocating mass when it is still attached to the crank you will only weight a percentage of the rod. this is like weighing the back wheels of a truck and saying it weighs X tonne. shouldnt you have to weigh the rod and piston seperate from the crank. I think you will be out by more than half the weight of the rod

Yes you'er more or less right, but this truck rotates at the front and reciprocates at the back.

Remember this is the KISS method and is a compromise. You could do a hell of a lot of math, and its still a compromise, just a smaller one.

The middle bit (Beam) of the rod poses a problem. It is neither totally rotating or reciprocating. It sort of wiggles. And the portion of reciprocating to rotating varies depending on the length of the rod.

Weighing the little end with the rod horizontal and free to rotate on the big end has been found, to be a good practical approximation of its reciprocating mass regardless of the rods length and works out to be about 1/3 of the rods total weight.

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[TZ350]

Looking back I see I have left a photo out of one of the steps. it should look like this:-

Weighing the little end by its self.

When I get to work Monday I will get a good photo and quickly re-post them all in their proper order.

[sonic_v]

Force due to reciprocating mass given by following equation

Force = mass * r * w * w * (cos(angle) + cos(2 * angle) / n)


mass : reciprocating mass
r : crank throw, usually half of stroke
w : 2 * pi * revs/sec
angle : crank angle from tdc
n : rodlength / crank throw

The second term in brackets is the contribution of the secondary force. As not a lot can be done about it
poss best to ignore thus equation simplifies to

Force_primary = mass * r * w * w * cos(angle)


Hence force is directly proportional to the square of the engine speed.

All that this means is that the KISS method of balancing a crank is correct as all forces involved are proportional to square of engine speed.

[TZ350]

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The KISS method of balancing a single cylinder 2 or 4-stroke.

Its all in the pictures:-

Pic-1 Find the total reciprocating Weight (Mass)
Pic-2 Find the Little Ends reciprocating Weight (Mass)
Pic-3 Find the Balance Facter (Ie. 65% is 0.65 X the ToTal Reciprocating Weight (Mass))
Pic-4 Leave the Little Ends reciprocating Weight (Mass) on the Scales
Pic-5 Attach the rest to the crank.
Pic-6 Balance the Crank.

From Phill Irving. page 109 "the wheels will roll freely along the straight-edges and show no tendency to settle in any one position; if not, the pin will go to the top or bottom according to whether the Counter Balance is to heavy or to light. Correction is usually made by drilling the rims."

Very simple, very effective, a very accurate way to balance a single cylinder crankshaft staticaly. If anyone can come up with a better static balancing method, Thomas and I would like to hear about it.

To find the existing balance factor of a crank shaft, you just more or less work through this process backwards.

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[TZ350]

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stuff the PM stuff... i think there are a couple of us that would like to know....

Ok ajturbo, this is what I've done to fit TZR wheels to my RG50 Frame.

Pic-1 Bore the bearing housing right through and retain the bearing on the inside by a circlip or locktight.

Pic-2 Machine the sprocket carrior right back. Fit to the outside brg a small stepped sleeve with a 3mm sholder, Just like the original one on the inside of the back wheel. Trim the spacer part of off the inside sleeve. I used two of those spacer sleeves that are found between the sprocket carrior and back wheel brg, after trimming the spacer part of. File the swing arm slots for the TZR axle, Take care, must be accurate.

Pic-3 Mill both sides of the back wheel to the bearing including the disk mounts. I intend to weld the rear brake calaper mounting bracket to the 15mm long spacer. Planing on using a RG50 or Pit-Bike caliper.

Pic-4 Mill both sides of the front wheel back to the bearings, GP125 forks, RG50 Tripple clamps (RG50 legs will work too). TZR Front wheel mounts in backwards. Use RG50 or Pit-Bike caliper and need to make new calaper mounting bracket

Pic-5 Wheel brg sits flush against fork leg. The other side has a 15mm long spacer. Drill fork legs for TZR axil. Shorten and re-thread axil.

Pic-6 Made little mounting brackets to adapt RG250 footrest brackets to the RG50 frame.

Sorry, I have only got as far as having the wheels sitting properly in the frame. I have not done anything to the motor yet.

Hope this is a help to you.

.

[F5 Dave]

Good grief, that has 6 steps, AJ can't even make it around with a dozen fine quality beers to get a free disc. Expecting him to machine something to fit is quite optimistic.
Those a RG250 Mk2 or 3 brackets as I have found out today (I have some mk1s in the shed).

[bucketracer]

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When I was around at the team ESE workshop yesterday I had the great fortune of meeting Thomas. We got talking about small 2-Strokes and drive-ability.

He showed me a RGV250 cylinder and pointed out the black oily gunk in the transfer ports. This gunk was high up in the port where the port exits into the cylinder. It was obvious that at some point in the rev-range there was blowback happening when the transfers opened.

Thomas pointed out that if this blowback could be stopped it would greatly widen the power band of the motor. He then drew some pictures of how it might be done using Fluid Diodes and told me that a Scroll Diode would probably be more effective in the transfers on a 2-Stroke than a Vortex Diode.

He said that in steady flow conditions the Vortex Diode looks like it would work better in the inlet but in a 2-Strokes unsteady flow the Scroll Diode has proven best. And that at high RPM the Scroll Diode is more effective than a reed valve. Looking at the pictures it all made sense.

The Team graciously gave me the OK to post these ideas and said they are looking into using it themselves and Fluid Diodes have been run experimentally in 2-Strokes. Where they showed no extra power but no loss of power either and a lot of real promise for widening the existing power band.

So here's a first for Buckets, to my knowledge anyway, the idea of using Fluid Diodes in the transfers and inlet to reduce blowback and thereby broaden the power band.

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[ajturbo]

Good grief, that has 6 steps, AJ can't even make it around with a dozen fine quality beers to get a free disc. Expecting him to machine something to fit is quite optimistic.
Those a RG250 Mk2 or 3 brackets as I have found out today (I have some mk1s in the shed).

yeah sorry i was late... but i finally made it...

.



Ok ajturbo, this is what I've done to fit TZR wheels to my RG50 Frame.

Pic-1 Bore the bearing housing right through and retain the bearing on the inside by a circlip or locktight.

Pic-2 Machine the sprocket carrior right back. Fit to the outside brg a small stepped sleeve with a 3mm sholder, Just like the original one on the inside of the back wheel. Trim the spacer part of off the inside sleeve. I used two of those spacer sleeves that are found between the sprocket carrior and back wheel brg, after trimming the spacer part of. File the swing arm slots for the TZR axle, Take care, must be accurate.

Pic-3 Mill both sides of the back wheel to the bearing including the disk mounts. I intend to weld the rear brake calaper mounting bracket to the 15mm long spacer. Planing on using a RG50 or Pit-Bike caliper.

Pic-4 Mill both sides of the front wheel back to the bearings, GP125 forks, RG50 Tripple clamps (RG50 legs will work too). TZR Front wheel mounts in backwards. Use RG50 or Pit-Bike caliper and need to make new calaper mounting bracket

Pic-5 Wheel brg sits flush against fork leg. The other side has a 15mm long spacer. Drill fork legs for TZR axil. Shorten and re-thread axil.

Pic-6 Made little mounting brackets to adapt RG250 footrest brackets to the RG50 frame.

Sorry, I have only got as far as having the wheels sitting properly in the frame. I have not done anything to the motor yet.

Hope this is a help to you.

.

thanks heaps.. now to find a TZR wheel...

[Skunk]

thanks heaps.. now to find a TZR wheel...

I don't have any... Skunk Control does - try your luck if you're that stupid/brave.

[ajturbo]

I don't have any... Skunk Control does - try your luck if you're that stupid/brave.

one thing at a time...

first i need the fork seals replaced

then the front disc (thanks dave)
then the new front brakes... then to bed them in...

then a new front tire

THEN the new rear... but that will be after the GT gets going...

but it is good to know it can be done easily and i have a friend who wants to help with doing it...