ESE's works engine tuner

[41juergen]

The software is scary good, and for whatever reason ( I simply dont care ) the crank power if estimated with all good inputs to the sim
will translate to close to 12% reduction needed to account for gear/chain/tyre losses on a Dynojet.
Contact Neels the code man at vannik@mweb.co.za pay your money and you are away.

Dont get confused,the RZ400 ( for F3 or Superlight ) info I just posted, isnt the same engine I detailed a bit further back - that was a TZ400 using a 6 port 3G3 cylinder for pre 82 Post Classic racing.
In the TZ400 the A duct being shorter than the B/C is from dyno testing done many ( MANY ) years ago by Helmut Fath ( my Hero ) who tuned for John Eckerold among others ( Freddie ).
There is no room in the TZ350 cylinder for more inlet area, the sides are 1mm away from the stud holes as it stands.
It is possible to make larger screw in studs with cutaways in them and 3 port the Exhaust, but as the rod angularity pushes the piston against the inlet wall
I dont think anyone has ever put boyesens into an RD/TZ/LC - I never considered it, maybe it is possible.
The inlet area is the big mechanical issue in the older Yamaha design as the studs are so close together, but by fitting an inlet divider to help the piston wear issue
( just as a 250G killed them also ) and adding twin boost ports, the power is respectable.

The RZ400 is a different story altogether.

This is how I did some longer time ago the boost ports into my RZ. Also I widened up the reed case to fit the bigger NSR125 VForce 3 cages (with the stuffers and an other inlet rubber replaced nowadays)... Of course not as good as your setup with the CPI barrels...

[wobbly]

That looks like a nice job on the RZ cylinders.
But possibly not needed nowdays as VF have a new reed for the Banshee that is a big step ahead of the VF3.
The RZ needs plenty of inlet capability when tuned really hard, but the CPI Cheetah cylinder had CR250 size reeds ( 68mm wide )
that needed to be offset outward to make them fit.
Calvin and I had a major disagreement about this, until I fitted the smaller 60mm CR125 VF3 ( looks the same as your NSR reed )
and offset them back onto the cylinder center, with a 6mm stuffer plate down one side to equalise the flow.
This change made +5Hp, and the CR125 reed is capable of even more than the engine could mangage.
So bigger in this case for shure wasnt better.

[Yow Ling]

How to you time a power valve when working from scratch ?

This is the plot from a KR150

The next question is, I don't think there is any adjustments to be made on the motor?



Thanks Wallace

Ok so you dont want to set the powervalve you want to set the ignition timing, my understanding was the early krs had 2 steps and needed a battery which you have removed, is this a development class bike or a Cams150 bike if it is a development class bike then you should only run stock timing.
There is no mechanical advance on the ignition , the powervalve is mechanicaly operated

[wobbly]

The mechanical PV mechanism is almost always set by the tension of a spring resisting the movement of balls up a ramp.
Its easy to shim the spring to make it open later ( looks like the KR is opening way too soon ).
But the issue then is that it may be fully open at a later rpm, but the more you shim it, the faster it opens.
This is usually not whats needed.

Its easy enough to set a PV from scratch, do the dyno run with it locked down. then one with it locked up, and one in 1/2 open position.
Overlay the graphs and the 3 points are then easy to plot.
This will be impossible to replicate with a mechanical servo.
But using the EXUP motor off an R1 its cheap and easy to add an electronic setup driven by an Ignitech.
When people put pipes on an R1 they always dump the EXUP, so they are available off Ebay for chips.
Honda also did a cable servo PV in 2004 on the CR125, so those bits will work as well.
Here is the setup on a KTM250.

[TZ350]

Ok, another RG50 run on the dyno.



Blue line = exhaust dam plus a nozzle that was 90% of the open part of the exhaust port window. Red line = no dam and nozzle that is 90% of the total exhaust port window.



Green line, our original best with an 85% Ex, no dam and no nozzle but since then we tried to improve the flow direction of the "A" transfer port windows. We are waiting on the delivery of a decent porting tool so we can shape the "A" port properly as we suspect our previous efforts have only made them prone to short circuiting.

[speedpro]

I'm giving you another week to get to 6hp.

[TZ350]

I'm giving you another week to get to 6hp.

We are working on it, and well on schedule thanks .....

[ief]

If the lesser result was due to (more) shortcutting wouldn't the revs go down instead of up TZ?

[RAW]

I would love to, Raw. All I need is a 64 bit laptop. Do you want my bank account number?
Or all you'd need is a Windows 98 emulator. I can recommend VMware Player. I use it on my 32bit Windows7 machine. It's free. Last time I checked, laptops weren't.

Better check Dosbox itself, Gamma. That is one emulator I can not recommend. It's a fleeced version of MS-DOS 5 and it won't run most of my programs.

Haha Frits, your bank account details or your money is of no interest to me, thought provoking information, knowledge is all I wish for, teach me how to & I may just be able to do you proud

[TZ350]

Green line, our original best with an 85% Ex, no dam and no nozzle but since then we tried to improve the flow direction of the "A" transfer port windows. We suspect our efforts with the "A" ports have only made them prone to short circuiting.

If the lesser result was due to (more) shortcutting wouldn't the revs go down instead of up TZ?

I am not a 100% sure about this, but I think the effective short circuiting decreases as the rpm goes up, less time maybe?

[peewee]

We are waiting on the delivery of a decent porting tool so we can shape the "A" port properly as we suspect our previous efforts have only made them prone to short circuiting.

get some vinamold while your at it. I thought I had my A pretty good until I made some molds with the vina and seen they weren't as good as I thought

[marsheng]

Ok so you dont want to set the powervalve you want to set the ignition timing, my understanding was the early krs had 2 steps and needed a battery which you have removed, is this a development class bike or a Cams150 bike if it is a development class bike then you should only run stock timing.
There is no mechanical advance on the ignition , the powervalve is mechanicaly operated

CAMS bike. I have no idea where the battery would be connected. One wire comes from the magneto and goes straight into the coil. There is no CDI box or rectifier. The only possibility is the CDI (which must be very small) is built into the coil itself. Only one space lug to the coil and an earth.

The bike as a Tyga Performance exhaust so I'm guessing the pipe and the mechanical advance are not quite synchronised.

Cheers Wallace

[marsheng]

Its easy enough to set a PV from scratch, do the dyno run with it locked down. then one with it locked up, and one in 1/2 open position.
Overlay the graphs and the 3 points are then easy to plot.

Thanks Wobbly, I will try this and see what it gives. I don't need the full power range, just enough to keep it between gear changes.

Cheers Wallace

[AndreasL]

get some vinamold while your at it. I thought I had my A pretty good until I made some molds with the vina and seen they weren't as good as I thought

+1

Can't stress enough how right you are peewee!
Was surprised how bad my transfers were. I took my time measuring them using all kinds of tools, but the Vinamold told the truth.

[Frits Overmars]

The mechanical PV mechanism is almost always set by the tension of a spring resisting the movement of balls up a ramp. Its easy to shim the spring to make it open later.. But the issue then is that it may be fully open at a later rpm, but the more you shim it, the faster it opens. This is usually not whats needed. Its easy enough to set a PV from scratch, do the dyno run with it locked down. then one with it locked up, and one in 1/2 open position. Overlay the graphs and the 3 points are then easy to plot. This will be impossible to replicate with a mechanical servo. But using the EXUP motor off an R1 its cheap and easy to add an electronic setup driven by an Ignitech..

Of course an electronic power valve governor is preferable to a centrifugal one (and let's not even mention a pneumatic one). But if you are compelled to use a centrifugal setup, a highly progressive spring could help. Space permitting you can approach that with a second, shorter spring, floating inside the original spring, which will give you a two-step spring constant.

Thanks Wobbly... I don't need the full power range, just enough to keep it between gear changes.

Reality is going to kick you in the face, Wallace. No matter how good a rider you are, one day someone will block your line and you'll lose one second getting back into the power band. And in racing one second is like a week...