ESE's works engine tuner

[wobbly]

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.

[TZ350]

Page 1430 links list .....

I have tuned it a bit now, runs smoother on idle, but as there is no venturi in this carb i figure it will work better on a engine with bigger displacement.
An engine that pulls more air before getting into the pipe so to speak.
I still have this HUGE gap in power when giving it full throttle, it just dies, no fuel is drawn into airstream, until i hit ~11000rpm(when the pipe is pulling hard)

I feel it´s the drawback on this model of carb, it´s a 'slide' model.

Rgds.

SwePatric...

Provided that there are NO air leaks anywhere with in the carb and fuel lines, and the carb is mounted with the pump assembly to the top... The first thing in getting rid of the throttle lag, is to increase the volume of fuel in the chamber located above the fulcrum arm. This makes more fuel quickly available to reach the venturi when the throttle is snapped open. To do this simply raise the fulcrum arm height. Be aware if the fulcrum is raised to far, the back side of the metering diaphragm will make contact with the pump body and prevent the fuel inlet seat from completely closing. To check for this.... After setting the fulcrum arm height, with the pump assembly removed, re-set the pop-off back to the original setting. Then remove the needles put the pump assembly back on and re-check the pop-off through the fuel inlet. It should be with-in less than 1 psi to the same reading as when the pump is removed. Usually the fulcrum height dimension is measured from the gasket surface to the top of the fulcrum arm. With .010" increments being a common adjustment. Lower pop-off settings will also help get rid of this lag, but as you have already seen lower pop-off will have other detrimental effects. If you have the diaphragm start hitting the pump, but still want more volume. An additional gasket can be placed between the metering diaphragm and the pump body. When set at the same pop-off, lighter rate springs also slightly richen up the throttle opening. Hope this helps.... Kermit Buller

What sort of pop off pressure is being used in the pumper now ?
I did a 100cc air cooled shifter engine years ago for a restricted kart class, that used a Tillotson 26mm slide carb.
The factory setting for this was 12 psi, but to get enough fuel into the low end transition circuit I had to eventually go to 1/2 this at 6 psi
with the lever height raised 0.5mm higher than stock as well.
The other "trick " is reverse jetting,with something like 2.5 turns on the L jet and 0.25 on the H, but this then needs a higher pop off.
This works well, as the L circuit is air corrected late in the fuel curve and it leans out past peak power, just whats needed.

Tillotson HL360A 24mm carb on TeeZees 28rwhp 1978 Suzuki GP125 engine.

The Keihin that came off the Honda RS125/250 has a PJ solenoid with a Viton tip.
It is the same as was used by the later Aprilia - it had pwm control,the Honda just used an on/off from the ECU.
The part is the same as is used I believe in a Fiat Uno and several other carbs as an idle air controller.

And re the PVL ignitions.
The analogue black box stator and coils are used by the thousand in KZ2 kart engines, so most are a straight line as mandated by the CIK.
Other stators have higher resistance ie more,thinner wire, and this gives a little more retard curve with no electronics involved.
You can buy stators for a Banshee that have the max amount of wire in the coils, so they will start with only minimal kickstart turns.
These are cloth covered coils ( called 5000 wind ), but even they only retard about 10* from 2000 to 10,000 - again pretty useless compared to the amounts of retard
and the curve shape we use now in a cheap Ignitech setup.
PVL make digital, red coils,and there are a few good versions of these, but 15 years ago you paid E500 to have one programmed for you - yea right,no thanks.

Wobbly, the power jet on the Keihin ? Is that an on / off or a pulsed type pj

Pumper carbs are alot more complex than you would think.
The 3 main tuning variables are pop off pressure, diaphragm lever height, and needle positions.
What are these variables at the moment - if you dont know, and or cant change all these,then you cant tune one.
If you can tune the top end OK with the H needle, but need the L out too far to get response off idle then you need to drop
the pop off a couple of psi.
This will then allow much less L needle but still be rich enough to accelerate off idle.
But then the H needle will need to go in some to lean off the top end.

The other issue I can see is PVL.
What is the stator coil resistance - as most of these ignitions are useless on a racing 2T as they have almost no retard at all.
If its 50 ohms you have a straight line ignition off a KZ2, useless - if its 200 ohms then you have around 7* retard, still useless.

Was surprised how bad my transfers were. I took my time measuring them using all kinds of tools, but the Vinamold told the truth.

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.

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.

Yeah, toluene used to be advertised as 'methyl benzine' as used in Shell 'super' petrol ( along with tetra ethyl lead).

Here are some recipes for home blending.. www.gnttype.org/techarea/misc/octanebooster.html

& the TEL is still available as an additive 'Octane Supreme 130' www.hi-flow.com/hp016os.html - the lead works
- as a lubricant for highly stressed 2T parts, look how much power/reliability was lost from G.P. 2Ts - when it was banned..

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.

And as I have said a dozen times on here, its only in lawnmowers that the dropping piston has anything to do with promoting flow
from the conventional case - thru the transfers,as there is more pressure above than there is below the piston at TPO.
The Ryger is using a very small trapped volume, that is compressed substantially by the larger diameter piston portion.
Thus it simply doesnt need a ton of blowdown to reduce the combustion pressure above the transfers, and as well it doesnt need the big negative pressure
ratio created by the diffuser to pull mixture into the cylinder when the piston is at BDC.
So a single Ex port seems entirely reasonable and expected.
The top end workings I believe we have pretty much guessed the trickery, as for the 30,000 rpm capable bottom end - darkness and guessing are really confusing
and we are not even close to reality yet.

It almost looks like a return to the origins of the 2 stroke where the piston was assumed to do all the pumping work. Still trying to visualise whether the under piston pumping setup is more efficient than the usual crankcase volume. Certainly plenty of transfer volume to provide mixture and as dave notes, it's provided with plenty of inlet area too. If it's a more efficient pump, it may not need the usual triple exhaust to generate flow...
At least we can now see why it's a short rod. I'd been assuming a trunk piston as it does seem to be a wet bottom end, well it is and it isn't a trunk piston..

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

+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.

Yeah, toluene used to be advertised as 'methyl benzine' as used in Shell 'super' petrol ( along with tetra ethyl lead).

Here are some recipes for home blending.. www.gnttype.org/techarea/misc/octanebooster.html

& the TEL is still available as an additive 'Octane Supreme 130' www.hi-flow.com/hp016os.html - the lead works
- as a lubricant for highly stressed 2T parts, look how much power/reliability was lost from G.P. 2Ts - when it was banned..

If you want to tip carbs up steep then Lectrons are the go.
They flow way more air than any round slide, are easy to tune and are period legal for Pre 82 Post Classic if thats important, and were used by King Kenny
on TZ750/500 in the early 70s..
As long as you keep the powerjets reasonably small ( 60 ) the fuel curve is much better than any normal carb where the fuel circuits and air correction
overlap, that cause dips and bumps in the A/F readings.

The basic rule is that you cant have a radiator thats too big.
But running Methanol will basically turn an air cooled motor into an efficient an engine, as a normal watercooled.
This basically means that the aircooled wont go off due to thermal overload like it will do naturally on petrol.
But running a watercooled on meth means it will be hard initially to get any temp into the water, so my advise is to use a small rad but plumb it with a bypass
thermostat.
This will naturally reduce the water cooling effect early in the passes, but when the temp starts to rise it will then use the water to do its job.

I think I get it. with less temperature difference there will be less heat transfer to the water ? ive got to either buy a radiator or have one made (either larger or smaller than whats currently available, based on what ever advice you could give me). this is a methanol drag racing bike remember. to reduce weight ive seen some guys use just a very small rectangle aluminum tank, so water can still be pumped through the cylinders and head but there is no fins or tubes on the tank, basically just a rectangle alloy box. other guys use a radiator but its very small, to reduce weight I suppose.

i guess those methods would work for one run and shut the engine off but i need a system that offers good cooling for continuos multiple runs. from what ive seen, the water temp is lower with methanol but eventually it starts to creep up near that of what you would expect from a average 2t gas engine. do you have any rule of thumb for radiator size ?

A small pot of water will absorb heat slower than a large pot. Moreover the water in that small pot will heat up quicker, so the temperature difference between water and stove drops, slowing heat transfer down even more.

I didn't say the volume should be small. I said that a large volume of slow-moving, almost stationary water is not effective. Water passages should be narrow so that most of the water is in contact with the walls instead of flowing down the middle without touching the hot metal surfaces. Narrow passages will also keep the flow velocity up, which helps heat transfer from those surfaces to the water.

frits did you say the volume of water in the cooling system should be small and move fast ? is it like a small pot of water on the stove could absorb the heat a lot faster than a large pot of water ?

[MotleyCrue]

At what rpm would the exhaust valve be fully open on the RZ ?

[wobbly]

RZ400 powervalve timing

[adegnes]

Anyone know exactly what fuels the various options in engmod is based on?

Avgas, methanol etc. is self explanatory, but what exactly is "regular", "premium", "unleaded 95", "unleaded 100"?

I've used "unleaded 100" in my simulations, and need to get the same or preferably a higher octane rated fuel in real life - Simulations show massive detonation with "regular", "premium" and "unleaded 95".
"unleaded 100" is marginally ok.

Wish avgas wasn't so restricted in Norway.

Btw; my bike is up and running! Needs a longer belt + some minor fixes and dialing in the carb.

[ief]

I presume unleaded 95 is what is sold in the netherlands standard fuel, 100 what is sold in Germany (or is that 101?) Regular and premium no idea as well. (you did read the chasing detonation paper from Neels?)

See you have the powerspark, do you like it, what was the price?

[TZ350]

My bike is up and running! Needs a longer belt + some minor fixes and dialing in the carb. https://youtu.be/V73dVEfDjNA

Great job, I see there are lots of Spx video clips on Youtube, those bikes look like great fun. Please keep posting your progress.

[adegnes]

I presume unleaded 95 is what is sold in the netherlands standard fuel, 100 what is sold in Germany (or is that 101?) Regular and premium no idea as well. (you did read the chasing detonation paper from Neels?)

See you have the powerspark, do you like it, what was the price?

yep, read the paper. I'm perfectly fine with having to run high octane fuel(read: I'm eager to see the results of what I've built and don't want to tear down the engine for further modication yet)
Anyone have experience with mixing in some toulene in pump fuel? I've mixed 20/80 toulene/98 pump before with no ill effects. My test engine didn't need the higher octane and thereby it didn't prove anything other than that it wasn't short time damaging to the engine though.

[adegnes]

Great job, I see there are lots of Spx video clips on Youtube, those bikes look like great fun. Please keep posting your progress.

Thanks! I will!

[adegnes]

re Power-spark.
It's worked great for me so far, but I can't really say anything about it yet.
Sorry, can't remember what I paid, do a search, I think I did a post on it.

[TZ350]

It does not matter what your into, just get out there and do it:-

https://youtu.be/GEOiNjYIN7c

https://youtu.be/qFFVcyqBcl0

https://youtu.be/pu_LHxC3hB0

https://youtu.be/iI2xCACU_j8

So much one could do so little time ...

[AndreasL]

Which trick from the movies do you plan for your self TZ?

[TZ350]

Which trick from the movies do you plan for your self TZ?

There is just so much great stuff one could do .... ... but it takes me about a year to just build a new bike.

[J.A.W.]

yep, read the paper. I'm perfectly fine with having to run high octane fuel(read: I'm eager to see the results of what I've built and don't want to tear down the engine for further modication yet)
Anyone have experience with mixing in some toulene in pump fuel? I've mixed 20/80 toulene/98 pump before with no ill effects. My test engine didn't need the higher octane and thereby it didn't prove anything other than that it wasn't short time damaging to the engine though.

Yeah, toluene used to be advertised as 'methyl benzine' as used in Shell 'super' petrol ( along with tetra ethyl lead).

Here are some recipes for home blending.. www.gnttype.org/techarea/misc/octanebooster.html

& the TEL is still available as an additive 'Octane Supreme 130' www.hi-flow.com/hp016os.html - the lead works
- as a lubricant for highly stressed 2T parts, look how much power/reliability was lost from G.P. 2Ts - when it was banned..

[RAW]

If you don't cool the water it's a different situation. The more water you carry, the slower it will heat up and the longer it will take before your engine power collapses.

Yes: bigger!

That must be a beast of a motor. 11,4 kgm² (no slash between the kg and the m²) is a lot! It equals a massive steel flywheel with 440 mm diameter and 400 mm width. It would certainly be enough for a decent inertia dyno, but I'm a bit worried about the revs. 900 rpm is not a lot and that rotor won't be made of steel, so in order to prevent it from exploding centrifugally you may have to use a fairly big reduction from crankshaft rpm to rotor rpm. And alas, that increases the inertia requirement.

You may want to play a little with this program: Attachment 318780 It has attained the age of majority so I'm not sure if it will run on your computer. Just let me know.

Frits would you PLEASE upload a version that can run on Windows 7, 64 bit