ESE's works engine tuner

[Sandokan]

I think the whole CO2 hype is just a way to make us pay.
They found in ice cores tens of thousand years old that there is a cycle in CO2 variation.
It follows the solar cycle and it is seperated by 800 years.
The cycle is arround 12000 years and when the sun is at its "high" point then 800 years later the CO2 rises. The heating from the ocean takes a while and naturaly releases more CO2
All this has occured milions of years in the past where they measured way more CO2 that was present than during the présence of man or industry for that matter.

What Gore did was move the graphics so that the CO2 lined up with temperature

Breatheable air i have no doubt can be of bad quality but CO2 wont kill me at these predicted levels.

I want to ask if someone knows where to see the evidence of crude oil beeing off fossil origin.
I have been searching for many years but to this day not able to find it.

Sander

[TZ350]

Blue line is the pressure trace from the simulator and the yellow dots are indicators of when the readings are being taken by the pseudo MAP co processor. The oscilloscope screen shows 12,000 RPM, so speed and accuracy are good.

High/Low difference 1.50 @ 65% TP 1.00 @ 15% TP 0.75 @ 5% TP all at 12,000rpm.

It has proven to be a bit of a long road to being able to test out the crankcase pressure (Max-Min)*3 = MAP concept. Hopefully I am getting close. The first cut of the pseudo MAP co processor was a bit of a failure. So I got hold of an oscilloscope and developed a two stroke crankcase pressure simulator with another Arduino Nano. Took two weeks as progress was a bit slow but auntie Google helped a lot with how to go about C++ coding, timing and interrupts.

The simulator puts out a signal sweep from 500 rpm to 14,000. Signal out is an ignition pulse and high/low pressure trace. The big trick was to keep the pressure trace proportional time wise between ignition pulses so that the peak always happened at 135 ATDC and a low at 315. The pseudo MAP co processor is triggered each cycle from the ignition pulse then has to accurately find the 135 and 315 crank angle positions before reading the crankcase pressure sensor and translating that into a MAP reading for the EFI's CPU.

All this to find out if the crankcase pressure (Max-Min)*3 = MAP concept could be a reliable/usable indication of airflow through a two stroke motor that runs higher than 10,000 RPM and makes better than 10bar BMEP. Ie., a 2S motor that is very dependent on its pipe for performance. Ride ability is the problem. Higher than 10/10 and fueling suffers from un-predictable changes in air flow as pipe resonance collapses on small throttle openings.

10/10 seems to be the ride able cross over point. Anything under 10/10 can be fueled using the Alpha-n topology as air flow is reasonably consistent. But over 10/10 air flow becomes increasingly variable depending on the resonance action of the pipe. Over 10/10 some way of seeing changes in air flow are needed. Something like the 4S MAP concept. The EFI KTM lives below the 10/10 performance barrier. Making big power and rpm with EFI is easy but getting big power and high rpm and ride-ability coming back onto the throttle is the issue over 10/10. I am trying to do better and push past into the 10/10 performance death zone and still have a ride-able bike.

[Michael Moore]

The EFI KTM lives below the 10/10 performance barrier.

Very impressive, I look forward to you being able to utilize this new developmen to solve the problems you are having.

I only have one carburetor to my name, a new/unused 38 PWK I purchased for the 2015 KTM 250SX track day project. EFI sounds appealing for my KTM as I'd rather keep my hands clean while screwing up the jetting with a lap top vs screwing it up by changing jets with fuel spilling on a hot engine. But that would depend on being likely to get the engine to run acceptably with EFI. I could buy the OEM TPI ECU/parts but about 5% of those bikes seem to have weird running issues. The Athena/GET replacement ECU for the TPI model sounds like it runs well and is readily available, and there's a plethora of capable aftermarket ECUs if I wanted to try and roll my own conversion.

10 bar is 145 PSI. My copy of Bell's book indicates that a 50hp 250MX (like my KTM 250SX with a Pro Circuit 2 extended power at higher RPM pipe) seems like it should probably be around 120-125 psi (8.5-9 bar), and since it would be a track day engine I don't see any need to exceed 9500 RPM. Does it seem likely that the 250SX would be sufficiently below the critical point to be able to run with Alpha-N if I had to go that way?

From a magazine test of the KTM 250SX PC2 pipe as an example of the expected performance level:

the stock pipe delivers incredible midrange but falls off quickly after its peak at 8200 rpm where it was making 47.30 horsepower. With the Pro Circuit Works pipe installed, peak is moved to 49.60 horsepower at 8300 rpm. That is a 2.2-horsepower gain at peak, but most important, the pipe didn’t fall off as quickly after peak as the stocker. The Pro Circuit pipe made the same power as the stock pipe from 5000 rpm all the way to 7200, then the Pro Circuit pipe made 1 horse more at 7500 rpm, 1.6 more at 8000 rpm and 4 horses more at 9000 rpm.

cheers,
Michael

[TZ350]

10 bar is 145 PSI. My copy of Bell's book indicates that a 50hp 250MX (like my KTM 250SX with a Pro Circuit 2 extended power at higher RPM pipe) seems like it should probably be around 120-125 psi (8.5-9 bar), and since it would be a track day engine I don't see any need to exceed 9500 RPM.

Does it seem likely that the 250SX would be sufficiently below the critical point to be able to run with Alpha-N if I had to go that way?

Yes I think so. But it is dependent on the pipe. The more the pipe shifts air when its working, ie higher performance the less likely the Alpha-N fueling topology will be suitable.

Flettner has a 50hp Kawasaki Big horn running E85 and his friend Wayne has a Yamaha YZ250 on petrol. Both running EFI Alpha-N fuel control mapping and I think both run near to 9,000rpm. I expect E85 or a methanol/mix if allowed would be a great help for fueling.

BigHorn https://www.youtube.com/watch?v=eleqBGvOM4M

First start of the Yamaha YZ250 https://youtu.be/hOGZ5llowoU

The issue with greater than 10 bar BMEP is that when you close the throttle the wave action in the pipe collapses and there is a drastic change in air/fuel ratio, Alpha-N can't cope with that. less tuned bikes can get away with it.

Above 10,000 RPM you need staged injection, a small injector for tune ability and a big one to get the job done above 10k in the diminishing amount of time available. Both injectors deliver about the same amount of fuel per revolution but above 10k rpm you need something big to get it in there quickly.

KTM have only two injectors, one in each "B" port. at low speed they fire them alternately and above a certain point they fire them together. That is a very clever way of getting staged injection. Although you may not have fired an injector on that side there is always some vaporized fuel present from the last injection cycle.

From my experience a 2S motor does not seem to care much if there is an imbalance in delivery so long as the sum of the air/fuel trapped in the cylinder is correct and mixed properly. An alternating imbalance is Ok but the motor will kick up a fuss after a few revolutions if there is no fuel at all coming from one side. Probably inconsistent mixing in the cylinder.

Making power and tune ability at WOT where airflow is consistent is very easy with 2S EFI. Above 10 bar BMEP it is shutting the throttle approaching the apex where things go wrong. The motor loads up and won't come back on until it has cleared the Alpha-N over fueling out of its system. Alcohol based fuels would be a help here.

[TZ350]

Successful Video of the Two Stroke Pseudo MAP concept: MAP gauge is bottom left.

Some smoothing required and the bike is just idling, I need another pair of hands to video a dyno run, but for now things look promising for a four stroke like MAP value that can be used in EFI VE volumetric efficiency tables. A realistic MAP value from a 2S that indicates real changes in air flow has to be a bit of a first, anyway I am excited about it. Hopefully, with a bit of development this might be the answer to that dreaded ride-ability problem.

At this point the indications are that the crankcase pressure (Max-Min)*3 = MAP concept could work.......

A better view of the MAP gauge:- https://youtu.be/xDixcBOg98U

[Tim Knopper]

the stock pipe delivers incredible midrange but falls off quickly after its peak at 8200 rpm where it was making 47.30 horsepower. With the Pro Circuit Works pipe installed, peak is moved to 49.60 horsepower at 8300 rpm. That is a 2.2-horsepower gain at peak, but most important, the pipe didn’t fall off as quickly after peak as the stocker. The Pro Circuit pipe made the same power as the stock pipe from 5000 rpm all the way to 7200, then the Pro Circuit pipe made 1 horse more at 7500 rpm, 1.6 more at 8000 rpm and 4 horses more at 9000 rpm.


Got pipe from DPR what a difference on the track

[TZ350]

Got pipe from DPR what a difference on the track

That is very impressive gains, I like it.

If your still looking to fuel inject it. More power and a wider spread and in the grey RPM zone. I would be vary wary as the better the symbiotic resonance in the system and pipe the less Alpha-N mapping will be possible as a complete fueling control strategy. You could drag race it no problems, but as far as fine throttle control is concerned you may have difficulties. I think you are truly heading into the area where you need a "Blended" approach. A mix of Alpha-N and VE volumetric efficiency. But producing a MAP or MAF value for the VE table is the trick with two strokes.

[wobbly]

I am working on a small race engine that has a pressure fed roller big end.
The original rod has the old fashioned copper M cage and the small end is too small ( both fail in race service ).
Thus I have tracked down a modern KTM rod that is sized for the same big end pin but uses a silver plated flat
big end and the small end is 1mm bigger.
All easy so far .
Both engines run the crank in the same direction and have the oil feed in from the same ( drive side ) flywheel.
BUT , the old pin has the oil feed hole on the trailing side , 90* from TDC.
The KTM has the feed hole on the opposite ,approach side , 90* from TDC.
Does it matter.

[Grumph]

I am working on a small race engine that has a pressure fed roller big end.
The original rod has the old fashioned copper M cage and the small end is too small ( both fail in race service ).
Thus I have tracked down a modern KTM rod that is sized for the same big end pin but uses a silver plated flat
big end and the small end is 1mm bigger.
All easy so far .
Both engines run the crank in the same direction and have the oil feed in from the same ( drive side ) flywheel.
BUT , the old pin has the oil feed hole on the trailing side , 90* from TDC.
The KTM has the feed hole on the opposite ,approach side , 90* from TDC.
Does it matter.

In my experience, no. So long as there's a positive pressure in the feed, it shouldn't matter.

[husaberg]

In my experience, no. So long as there's a positive pressure in the feed, it shouldn't matter.

So the reason the holes they are at 90's from TDC and BDC is the clearances are changed at either due to compression and inertia. or is it for fatigue?
Or is it all about crankcase pressures? or all of the above

[Flettner]

it's to give the crap in the oil a chance to centrifugal out. Clean oil only makes it out the hole. Me thinks.

Crap will eventually build up in the hollow crank pin, so therefore perhaps the leading side.

[husaberg]

it's to give the crap in the oil a chance to centrifugal out. Clean oil only makes it out the hole. Me thinks.

Crap will eventually build up in the hollow crank pin, so therefore perhaps the leading side.

Norton

Bsa

the Japanese decided a filter might be easier.
early Hondas and Xr200's etc combined both.

[Grumph]

it's to give the crap in the oil a chance to centrifugal out. Clean oil only makes it out the hole. Me thinks.

Crap will eventually build up in the hollow crank pin, so therefore perhaps the leading side.

While it is true that crap will eventually build up in a hollow pin - as I can show you in some 4T pins - in a race 2T the crank life is such that when stripped you'd have to look hard to find any in there....

Husa, your example is a 4T with recirculating oil - and very rudimentary filtration. Not really comparable.

[TZ350]

While it is true that crap will eventually build up in a hollow pin - as I can show you in some 4T pins - in a race 2T the crank life is such that when stripped you'd have to look hard to find any in there....

Also 2T oil is not contaminated with combustion carbon.

[husaberg]

While it is true that crap will eventually build up in a hollow pin - as I can show you in some 4T pins - in a race 2T the crank life is such that when stripped you'd have to look hard to find any in there....

Husa, your example is a 4T with recirculating oil - and very rudimentary filtration. Not really comparable.

Pretty sure wob was talking about a 4t as well
What modern 2t have pressure fed big ends?