ESE's works engine tuner

**Muhr** · 19th July 2021, 08:47

Originally Posted by SwePatrick

As every engine differs, so ofcourse you need to edit this to suit the engine.
But, i don´t use it, it´s not interesting because what i wrote earlier.

Don´t let let it block your mind, forget it and go on with more useful stuff to do, like starting up your project

The simplified way, i hinted of that earlier, but again:

'If value is setup correct the enginepower should differ very little between the gears in a pull through the gears...'

And by that, just put in a random number and look at the difference, adjust until you´re happy.
(and still be asking yourself if it´s really correct)

I think a little like this! If we assume that we have a run of 6 seconds between 8500 and 14500 it is about 105 rad / s2 if we do it in half the time then it is about 210 rad / s2
If we then assume that we have a driveline weight of 6 kg and an inertia radius of 3 cm (dia 6cm). Very simplified but still ....
Then it would be something like 6 * 0.03 (M)*105*0.03/2 = 0.2835 MN linear, which should be at least 2-3x that at peak torque. As I said very simplified but you probably have something to add here ...

Of course small potatoes for you with the torque you present from an old mild sport oriented engine from the early 80's. But for a little guy like me, it makes a difference.
Or maybe I should just adjust the numbers until I'm happy.

**wobbly** · 19th July 2021, 09:05

A DynoJet has a fudge factor built into the software that cannot be adjusted.
It occurred during development , using a Harley as a test mule - it didnt seem to make enough power , so they " adjusted " it.
This was because the HD had huge , heavy flywheels , and wheels/tyres etc.
Now when we test a kart on one it seems to read high , due to very low inertial loads.

Even in this case we have to adjust the gear used to get a suitable runup time for the pipe to be hot enough , or add Eddy Current load % to slow the acceleration rate.
My engine dyno is calibrated , with load drop and rundown factors in the software , but I dont use the Sportsdevices engine inertial factor as all the engines are similar in this respect.
The engine dyno reads around 12.5% higher than a Dynojet , that makes perfect sense to me.

But at the end of the day the raw numbers make no difference at all.
Does one reed petal make better power , yes or no , as long as the dyno and my method is absolutely repeatable the answer is all that matters.
I have checked this dozens of times using the track data logger , plugged into a virtual dyno with NT sofware.
This converts the data into a Hp graph , and any change in power from the actual dyno , is reflected exactly as the same difference on track.

**adegnes** · 19th July 2021, 09:52

Attachment 349388

Cheers everyone!
Been a while. Yet again.

Don't know where to start.
First, Thank you TZ for consistently sharing my videos!
Thank you Ken for the emails, and the reminder to check out the ESE thread.
I've got a lot of reading up to do, at least a year back, maybe two, hell even three.
I'm more than halfway into that bottle, and tend to become overly philosophical at this point, now being no exception. Keep that in mind.
My absence is not merely lack of time(still a big part of it though), but also a conscious decision to shroud myself from the input of all the brilliant minds on here.
Ludicrous, I know. But you see, the best moments for me, are those moments when I've come up with something(to me) brilliant all on my own, with little external input. It might not really be that brilliant, and it might have been thought of before, but the feeling is still real.

After a while I get too curious and cave in, like now. Luckily I've got a lot of reading up to do.

I really believe I can make the most powerful two stroke ever(hp vs cc, must not forget to specify), eventually.
I mean, why settle for anything less?
It's all about the journey though, learning things, evolving, establishing connections between everything you pick up along the way. No matter how immediately irrelevant something seems, there's always something to draw from it.
Even wood chopping...

Anyways.

The PiP engine is up and running now with a bridged exhaust.
I'm not giving up on the 100% exhaust, just moving the experimentation over to a dedicated engine for just that.
Wobbly, I know it's proven tech, but I also know they ran that patented L-ring with a big dip in the middle of the exhaust roof(like that "W" port, just not as bad...)
With a proper chamfer/radius, and the right ring construction I think it can work fine without a "dip".

I'm set on Bonneville next year, and I need something running and somewhat reliable, had to turn down the amount of experimental stuff involved.

Don't tell anyone, but the brute force engine is mostly to see where I'm at in the fully-fledged-prototyping-facility-game.
Almost there.
I have a feeling it can produce some power tho, and lots of flames!
It's also kind of a relaxing project, a dumb engine, "brutus".

Picked up a telma retarder 2 days ago, building a load cell dyno. Was originally going for a diy hydraulic pump type, but changed my mind. Getting older, slowly more sensible...

Cheers!

**teriks** · 19th July 2021, 12:25

Originally Posted by ken seeber

Took a little vid of the engine running at lower speeds and no load. Does show a depression in DCI passages.

https://studio.youtube.com/video/D6EX3x8yptU/edit

Your link didnt work, (unless you log in, probably with your account at that).
http://youtube.com/video/D6EX3x8yptU should work though.

**F5 Dave** · 19th July 2021, 13:01

Originally Posted by wobbly

A DynoJet has a fudge factor built into the software that cannot be adjusted.
It occurred during development , using a Harley as a test mule - it didnt seem to make enough power , so they " adjusted " it.
This was because the HD had huge , heavy flywheels , and wheels/tyres etc.
. . .

Wasn't enough fudge. (Spookily I am actually munching some chocolate and biscuit baking goodness as I type). A mate (Chris Sayle) bought the first DJ in Wellington late last century.

He had some disappointed Hardly customers. Fortunately for them WMC bought a dyno and that gave 'the right figures'.

pity as they were easily parted with their money. Improvements Largely by removing the Thunder Wailing Budgie go faster parts they had bought. Also unpopular.

**ken seeber** · 19th July 2021, 16:40

Originally Posted by teriks

Your link didnt work, (unless you log in, probably with your account at that).
http://youtube.com/video/D6EX3x8yptU should work though.

Teriks,

Good spotting and thanks for that. My youtubing skills are clearly lacking....age.

Should get the thing running with the single DCI carb today/tomos.

http://youtube.com/video/D6EX3x8yptU

**speedpro** · 19th July 2021, 19:45

Originally Posted by Frits Overmars

Attachment 349331

It looks like the .3r section makes up 90degrees(.3r radius & .3r height) leaving 90degrees for the other 2 sections combined. Is there a preferred angular displacement for each radius section? I have drawn something like this but with 60degrees for each radius which "looks" OK.
Also, should there be a taper on the main body of the velocity stack and if so what angle, included or per side?
Application is a FI FZR250

**speedpro** · 19th July 2021, 19:54

Originally Posted by F5 Dave

Wasn't enough fudge. (Spookily I am actually munching some chocolate and biscuit baking goodness as I type). A mate (Chris Sayle) bought the first DJ in Wellington late last century.

He had some disappointed Hardly customers. Fortunately for them WMC bought a dyno and that gave 'the right figures'.

pity as they were easily parted with their money. Improvements Largely by removing the Thunder Wailing Budgie go faster parts they had bought. Also unpopular.

I recall one customer Hardly where the "Thunder Jet" had to be blocked to make the bike go properly(for a Hardly). Another had a small fortune spent on it with the result that it made the exact same horsepower as Viv's stock ZZR600 in back-to-back dyno runs

**ken seeber** · 20th July 2021, 00:21

Here's a quick vid of the DCI engine running on the main carb and the DCI carb, with no fuel, is opened up.
No explosions, it just revs up.....I'm excited.

https://www.youtube.com/watch?v=gmX4cD7x3F4

**Frits Overmars** · 20th July 2021, 01:08

Originally Posted by speedpro

It looks like the .3r section makes up 90degrees(.3r radius & .3r height) leaving 90degrees for the other 2 sections combined. Is there a preferred angular displacement for each radius section? I have drawn something like this but with 60degrees for each radius which "looks" OK. Also, should there be a taper on the main body of the velocity stack and if so what angle, included or per side? Application is a FI FZR250

That three-radii bellmouth drawing (it's an oldie from a German paper that's almost as old as I am) shows a fairly effective approximation of what theoretically ought to be a continuously-increasing radius.
As the local diameter of the bellmouth tightens downstream, the flow velocity increases and the bellmouth radius should also increase in order to keep the transversal acceleration of the air molecules within bounds and so prevent flow detachment, turbulence and pressure losses.

I take it that with "the main body of the velocity stack" you mean the cylindrical or conical part between the bellmouth and the carb.
Well, it has no right to be there at all. The carb should be at the beginning of the inlet tract, not 'somewhere in the middle' where inlet pulses may pass over the jet in both directions, each time picking up fuel and making carb adjustment a nightmare. You may get away with it if you have intake fuel injection, but that brings its own problems in two-strokes.

Originally Posted by ken seeber

Here's a quick vid of the DCI engine running on the main carb and the DCI carb, with no fuel, is opened up.
No explosions, it just revs up.....I'm excited. https://www.youtube.com/watch?v=gmX4cD7x3F4

Now imagine restoring the scavenging symmetry by having the engine breathe cold mixture with the correct air/fuel ratio through both side-mounted carbs

.

**SwePatrick** · 20th July 2021, 08:27

Originally Posted by Muhr

Or maybe I should just adjust the numbers until I'm happy.

With statement like this you won´t get far regarding credits in my bag.
I tried to say you are chasing things with minor interest, just go for the raw data as wobbly says.
Don´t bother if your dyno shows 200hp, if you have gained 1hp and have done it with good repeatibility you have done something good.

Use the exact same dyno all the time when developing.
Comparing to others, i always call it 'dick contest'

Talk softly and carry a big stick!

**Muhr** · 20th July 2021, 09:56

Originally Posted by SwePatrick

just put in a random number and look at the difference, adjust until you´re happy.
(and still be asking yourself if it´s really correct)

Originally Posted by Muhr

Or maybe I should just adjust the numbers until I'm happy.

Originally Posted by SwePatrick

With statement like this you won´t get far regarding credits in my bag.

Talk softly and carry a big stick!

Ok! I would like to avoid being in that bag.

**Vannik** · 20th July 2021, 20:04

I know this video is on diesel engine emission testing but about a third of the way in they show the crankshaft speed fluctuation in one cycle (well maybe 4 cycles

) and it is what Wobbly and Frits have mentioned a number of times in that in a 2T engine it influences how long the ports stay open:

https://www.youtube.com/watch?v=Yjh_U9LLxY4