ESE's works engine tuner

[breezy]

Google John Tice
give me a minute
http://www.smallenginemachineworks.c...inder_services
http://forums.everything2stroke.com/...round-the-Shop
http://www.everything2stroke.com/con...u-need-to-know
if your project is intesrting enough he will do a deal on doing it all

he used to make his own sleves and shows the process of casting them,
http://forums.everything2stroke.com/...the-Shop/page9
from memory he gets most of them from LA sleeve but he mentioned somewhere elese he calls N.W?
Northwest Sleeve Co.
https://www.manta.com/c/mmsq7lz/northwest-sleeve-inc
http://forums.everything2stroke.com/...the-Shop/page3

Bert Munro used to old gas pipe that was spun cast.
but i believe he once used a cast iron down pipe from a motel near Bonneville (not sure if that was in the movie or the book)

thanks for info Husaberg..

[Frits Overmars]

At which rpm should a rider change gears in a tuned Honda RS 125, say making peak at 12,7 to 13k rpm, isn't it a lost of time to let the bike overrev to 14k or more in low gears?

idealy, you shift each gear at different rpm's, as the ideal point to shift gears largely depends on the drop in revs and those drops change from gear to gear. Basicly you need a dyno to determine the ideal shift rpm's.

Romeu, I dropped my crystal ball again, so I will assume that your tuned Honda RS125 has the same power curve as a standard RS125 (many 'tuned' bikes have less than standard). I will also assume that you are talking about an RS125-NX4 because an NF4 and an NX4 have different gearbox ratio options.

Third, I'll assume that you use the standard gearbox option that came with the bike as it was shipped from Japan, as opposed to one of the other 647 combinations, made possible by the 4 options for first gear x 3 options for second, third, fourth and fifth gear each, x 2 options for sixth gear.

Fourth, I have to guess rider weight, initial velocity and acceleration distance. And then we'll see that JanBros is right: you should shift at the intersection points of the rear wheel thrust curves (plus a tad of overrev because of the air resistance-induced velocity-drops during the power-interruption periods of each shift action; are you still with me?)


H125 input values H125 power curve H125 gearbox H125 shift points-01 H125 shift points-02

In the above pictures I assumed an acceleration from 0 km/h over a distance of 800 meters.
In picture #4 you can see a lot of clutch slip, all the way from standstill to 94 km/h where the riding speed in first gear matches the 11200 rpm crankshaft speed of maximum torque. In theory you can accelerate even faster if you slip that clutch each time the engine rpm drops below the rpm of maximum torque.
In practice the clutch might not be too happy about this, and it would put a lot of extra heat in the engine, which in turn would not do the power much good.

Pictures #4 and #5 show that you have to rev the engine the most in first gear in order to minimize the rpm drop from first to second gear, but they also show that you do not need to rev it till maximum rpm. In fact, this engine would not even want to rev to the 14000 rpm that you mention in your question.

And there is a second factor playing a role here: the measured power curve is really only valid for one particular acceleration time. Measuring the same engine on the same dyno with a shorter gearing would give a shorter acceleration time, less temperature build-up in the exhaust pipe, and less willingness to rev.

Well, I hope this answers one of your four questions .

[wobbly]

Just to show whats possible with RS125 here are 3 rear wheel dyno runs.
One is a well tuned " customer " bike.
The next is a genuine A Kit engine
The 3rd is Azuma,s PV factory engine

[katinas]

This is from 1936 Michael Kadenacy patent Fig.6

6. A method of controlling two strokecycle internal combustion engines which comprises establishing communication between the cylinder and exhaust system during the flring stroke, providing for the issuance of the burnt gases as a mass, whereby the said mass moves outward and thereafter return from a point which may be within the said system, providing a permanent ree passage for the burnt gases to the limit of outward travel of said gases, preventing the entrance of fresh charging air into the cylinder until the said issuance of the burnt gases is in full progress, admiting fresh charging air into the cylinder when the said issuance of the burnt gases is in full progress and-causes a suction effect to be exerted in the cylinder while the exhaust port is still open, providing for said fresh charge to occupy the cylinder in the interval elapsing between the mass exit of the burnt gases and the interval when the pressure of tire returning gases becomes effective within the cylinder, shutting oi the said communication between the cylinder and the said exhaust system, after the said fresh h charge has occupied the cylinder and before the instant when the pressure of the returning gases becomes efective within the cylinder.

[dutchpower]

Just to show whats possible with RS125 here are 3 rear wheel dyno runs.
One is a well tuned " customer " bike.
The next is a genuine A Kit engine
The 3rd is Azuma,s PV factory engine

Sorry Wobbly.

Azuma had never a PV engine

[wobbly]

So the Azuma dyno run never happened ?

[dutchpower]

So the Azuma dyno run never happened ?

More then 400 runs only by Liégeois Compétition
5 A-kits for one season and you have to give then back to HRC

[RomeuPT]

Romeu, I dropped my crystal ball again, so I will assume that your tuned Honda RS125 has the same power curve as a standard RS125 (many 'tuned' bikes have less than standard). I will also assume that you are talking about an RS125-NX4 because an NF4 and an NX4 have different gearbox ratio options.

Third, I'll assume that you use the standard gearbox option that came with the bike as it was shipped from Japan, as opposed to one of the other 647 combinations, made possible by the 4 options for first gear x 3 options for second, third, fourth and fifth gear each, x 2 options for sixth gear.

Fourth, I have to guess rider weight, initial velocity and acceleration distance. And then we'll see that JanBros is right: you should shift at the intersecion points of the rear wheel torque curves (plus a hint of overrev because of the air resistance-induced velocity drops during the power-interruption periods of each shift action; are you still with me?)


H125 input values H125 power curve H125 gearbox H125 shift points-01 H125 shift points-02

In the above pictures I assumed an acceleration from 0 km/h over a distance of 800 meters.
In picture #4 you can see a lot of clutch slip, all the way from standstill to 94 km/h where the riding speed in first gear matches the 11200 rpm crankshaft speed of maximum torque. In theory you can accelerate even faster if you slip that clutch each time the engine rpm drops below the rpm of maximum torque.
In practice the clutch might not be too happy about this, and it would put a lot of extra heat in the engine, which in turn would not do the power much good.

Pictures #4 and #5 show that you have to rev the engine the most in first gear in order to minimize the rpm drop from first to second gear, but they also show that you do not need to rev it till maximum rpm. In fact, this engine would not even want to rev to the 14000 rpm that you mention in your question.

And there is a second factor playing a role here: the measured power curve is really only valid for one particular acceleration time. Measuring the same engine on the same dyno with a shorter gearing would give a shorter acceleration time, less temperature build-up in the exhaust pipe, and less willingness to rev.

Well, I hope this answers one of your four questions .

Great piece of pratical/theorical information, many thanks for your time and willingness. Some things I was guessing and you confirmed and changed!

[RomeuPT]

Ok, more info for this thread.... Sorry if it was explained before, or half way throught

it's easy to take a standard T port cylinder from a MX bike or std RS125 that has like 190/195º exhaust and raise it to 200º by doing a good round chamfer raising the port 1/1,5mm.

The thing is if looking at cylinders from factory that come with 200º we don't see that chamfer, it's mostly straight plain duct on the roof, 1min in paint .....



Doing this helps keeping duct volume low, the return pulse gases can follow this chanfer if big enought, or maybe not.

Would this need a dyno to confirm or is safe to say that will not be has good has a normal 200º port...

Thanks

[Frits Overmars]

it's easy to take a standard T port cylinder from a MX bike or std RS125 that has like 190/195º exhaust and raise it to 200º by doing a good round chamfer raising the port 1/1,5mm. The thing is if looking at cylinders from factory that come with 200º we don't see that chamfer, it's mostly straight plain duct on the roof .....

You must have been looking at cylinders from the wrong factory .

Doing this helps keeping duct volume low, the return pulse gases can follow this chamfer if big enough, or maybe not.

It sure will keep the duct volume small, which is always a good thing. And the radius will help both the outflow and the return flow, but the positive effect on the return flow will be small; keeping the return flow attached over the port edge would require a much bigger radius.

Would this need a dyno to confirm or is safe to say that will not be has good has a normal 200º port...

I'd rather say that it is better than a 'normal' 200° port, if only because you can always modify that radiused port into a 'normal' port, but you cannot modify it the other way round.
If you are lucky, the modification effect will be strong enough for a seat-of-the-pants conclusion. But then you still won't know just how big the effect was.
So, if you have access to a dyno, use it.

[wobbly]

The 200* port when used by Honda in A kit form had everything else changed as well.
The flange was different as was the pipe, the ignition curve, the PJ switch point, the cylinder head.
Trying to make a customer engine work with a high port only simply doesnt work.
Look at how different the power curves are.

Re the dyno curves - I got that sheet from Belgium,when I was looking at buying the rolling road software.
The two factory setups had been dynoed in secret, and i was told not to show this to anyone - but that was a very long time ago, and matters not at all now.
As it turned out I decided to go with an engine dyno,using SportsDevices , as kart engines became my main interest,and Jan told me that the Aprilias
were dynoed at the sprocket as well.

[RomeuPT]

The 200* port when used by Honda in A kit form had everything else changed as well.
The flange was different as was the pipe, the ignition curve, the PJ switch point, the cylinder head.
Trying to make a customer engine work with a high port only simply doesnt work.
Look at how different the power curves are.

Re the dyno curves - I got that sheet from Belgium,when I was looking at buying the rolling road software.
The two factory setups had been dynoed in secret, and i was told not to show this to anyone - but that was a very long time ago, and matters not at all now.
As it turned out I decided to go with an engine dyno,using SportsDevices , as kart engines became my main interest,and Jan told me that the Aprilias
were dynoed at the sprocket as well.

I don't really know how much is the gap from say a STD but tuned RS (changing ignition, PJ open point, 800mm exhaust, flange, well worked ports etc) vs A-kit bike.

This is mostly talk, I am not willing to pay for A-kit results just for my Drag NSR to have some fun at fridays and sunday meetings

[peewee]

hey guys just a update. I was able to do alittle testing today with some new things. previously I was having trouble with the crankcase flooding at small throttle openings (ran fine at full throttle) which made it difficult to clear the engine of fuel, so it was launching very rich until the excess fuel was sucked out. since leaning the needle had really no affect on the problem, I then suspected maybe the fuel pump was over powering the needle valve and pushing fuel up the needle bore and into the cylinder. I talked with lectron about this and they thought a different needle valve with smaller main inlet would solve the problem. so I got the new needle valve which is 2.5mm main hole with 6- 1.57mm secondary holes (original valve was 3.3mm main hole and 3-1mm secondaries). this didn't quit makes sense to me since I figured decreasing the main hole diam would increase the fuel pressure through the hole but I don't know. it did seem easier to clear the crankcase but ill do more testing to be sure. if this doesn't work then im thinking maybe go back to the 3.3mm valve and drill 6-1.5mm secondaries instead of 3-1mm.

last night I advanced the static ign timing slightly 3* and installed new #10 plug gapped at .76mm. mixed 1gal methanol at 11% oil for initial testing and be sure the tuning was ok. made another 1/2gal of premix with 3% nitromethane, 16% oil and 81% methanol (all percentages were by volume). anyways I made a couple full throttle runs of about 300' or so with the straight methanol to be sure the tuning was ok . it was running good, engine cleared out pretty easy and ran good at full throttle but I had both powerjets fully open so I wasn't sure if it would supply enough fuel with the nitro.

now it was time to try the other can of fuel . I didn't make it very far and the needle was extremely lean . ( I believe adegnes experienced this also in one of his videos when he was using the meth/nitro mix, as he drilled out his needle tube I think). by this point it was getting late so I packed up and went home. I got some video but the wind was so bad it didn't turn out well but next time ill try and get better video. im going to richen the current needle I have and hopefully I wont need a whole new richer needle but maybe so. also im probly going to install a 3rd powerjet and perhaps even a larger capacity float bowl as this will be some insurance incase theres a lack of fuel flow into the bowl. im not for sure yet if ive got sufficient fuel flow for full throttle as I didn't run the engine very long since the needle was so lean. next weekend I plan to spend a lot more time testing and ill report back what happens

even though I only mixed in 3% nitro by volume, I think it may have actually been a even hotter batch. by weight it would have been about 5% and the fuel temp was only 40* F (apparently the specific gravity of nitro is very unstable with temp changes). so im wondering if it was more like 10% in reality, based on some charts I found online. anyways im excited to richen the fuel system and try even higher percentages next time.

[TZ350]

Hi Peewee

Very exciting to see your nitro experiments, I have always wanted to try it myself.

I have not yet, but my plan was to get my bikes basic fueling nicely setup without nitro.

And the plan was to not mix the nitro into the fuel at all. The plan is to drop the nitro into the air stream through a switchable power jet. That way there is no need to richen or play around with the already good basic carburetor jetting.

The theory was that adding nitro by itself through a separate power jet to an already properly jetted engine added oxygen and "a little richness" to the carburetors original basic jetting because nitro caries slightly more fuel than oxygen.

So in theory with the base jetting correct the engine would run a little richer when nitro was being added separately to the air stream.

[adegnes]

Haven't had much time lately.
I have replaced the intake valve and will be back with further experimentation on methanol/nitro soon. As of now I've gone from 15.3 to 17whp, nothing changed except carb settings. The no intake valve thing is put on hold for a while, want to establish a baseline on this fuel and start modifying the cylinder and pipe.