ESE's works engine tuner

[adegnes]

Thanks for the videos and also thanks for the Norweigan girls.

[Frits Overmars]

Please let me know if there are any more problems. That HEAD-program should behave now.

Yes that's better. It doesn't run on an HP 200LX running MS-DOS 6 BTW.
A question though about the box containing the legend "Radius 6.84" in the attached pic: Is this the radius of the curve from point 2 to point 3? I set it at 6.5 in the parameters, but I'm guessing the program has corrected it to match the required CR?

It should still run under MS-DOS 6, but some command may have crept in that is too new, so DOS doesn't recognize it. I don't have DOS at hand so I can't test it now.
You assumed correctly that your 'radius 6.84' is the radius from point 2 to point 3, and this radius is the result of a calculation; it cannot be set by the user.
The program also offers the option to enter a radius at point 2, but this radius won't be displayed in the graph (I got lazy writing the necessary extra program lines). Besides, a radius at point 2 has proved to be undesirable.

I wrote the HEAD program for my personal use, so not every option will be clear at first sight. For example, you may have noticed that some questions show a zero in front of the question mark. That zero indicates that there may be another way of answering the question. Enter the zero and the next question regarding the same item will appear. Below you can see a couple of examples.
There is also an example of a diesel-type piston crown with an intruding-plug head. I'm not advising this kind of chamber; it merely shows what the program can handle.

[jfn2]

Hello Frits:
In your program it asks for 'squish clearance' and I set it at 1mm. Then it asks for 'squish clearance center gap' and I set this at 1mm also, but when the pic comes up it shows a squish of 0 for Z1 and a .95 for Z2. Also with a spherical topped piston I get Z3 and Z4 having the same dimension. How can this be? What am I doing wrong? Thanks

[F5 Dave]

Asking for a squish clearance of 1mm

[Frits Overmars]

Hello Frits: In your program it asks for 'squish clearance' and I set it at 1mm. Then it asks for 'squish clearance center gap' and I set this at 1mm also, but when the pic comes up it shows a squish of 0 for Z1 and a .95 for Z2. Also with a spherical topped piston I get Z3 and Z4 having the same dimension. How can this be? What am I doing wrong?

You're reading things that aren't there; that's all. The Z-values have nothing to do with squish clearances. They indicate heights, measured from point 1.
Usually you set Z=0 for point 1 but if for example you want to have a head that centers in the cylinder bore, you can specify a different Z1-value, and all other Z-values will be adjusted accordingly; this will make life easier for the CNC-operator.

Asking for a squish clearance of 1mm

Maybe that's wrong, maybe it isn't, Dave. I don't know the stroke of his engine. If it's 100 mm, he's doing fine with 1 mm squish .

[jfn2]

Thank you Frits. I now understand, mostly. I am working on an engine with a 54.5 mm stroke but I just threw in the 1mm to run the program.

[jfn2]

Bye-the-way I am using windows 10 with dosbox.

[Frits Overmars]

Bye-the-way I am using windows 10 with dosbox.

Thanks for the info. I'm surprised that the program behaves under Dosbox, because that really only contains a stripped-down version of MS-DOS 5, not MS-DOS 6.
Please let me know if it will cleanly save and load the head-data that you created.

[jfn2]

No it will not cleanly load and save the new results. What I do is to use the sniping tool in windows 10 and save the data and drawing screens into a separate file. To run the same file I must reload the data. Really no problem with this small of program and files. It would be tougher with a larger program. I could relearn dos commands and save it that way and make it work. Using the split windows in windows 10 I can view both the drawing and the data screens at the same time. Thank you for the program.

[peewee]

hey wob and frits I don't have a good way to test most of this engine stuff so maybe you can answer these question. I see on a lot of oem reed blocks theres no dividers. would dividers (horizontal and vertical) be useful mostly just for when theres a kink from the carb to the cylinder, so the air doesn't get piled up on one side of the crankcase or do they have a practical purpose even on straight inlets ? further more if you split the block in four sections with dividers would it make sort of like four venturis and the air would speed up ?

other question is about the fingers and the photos attached. if you cut out four of the fingers you gain the equivalent area of adding another reed petal. but with four large petals would they require a larger negative crankcase pressure to open them ? or is it better to keep the eight smaller petals ?

[wobbly]

Currently the fastest engines use the 2 petal setup as the extra dividers for 3 or 4 per side create more turbulence ( or double that in a VeeForce )
Extending the dividers both horizontally and vertically with airfoil leading edges also decreases the flow disruption caused
when the air suddenly hits a short support close to the petal.
The 2 wide petals will be alot stiffer, so will have to be thinner ( or waisted at the clamp face ) to achieve the same lift due to case depression assisted by intake column tuning.
I have seen tests adding vertical dividers to an older VeeForce ( that already has the horizontal wing shape ) and this made better power.
Newer ( higher flowing ) versions of the VeeForce have the vertical dividers now as well.

[breezy]

"There’s very little all the factories agree on, but engine rotation is one of them After sunshine, rain and fresh air, my favourite natural phenomenon is gyroscopic effect. This is because we wouldn’t be able to ride motorcycles without it. If you don’t believe me, try this next time you’re out riding: when you stop at a traffic light, don’t put your feet down. (And don’t send me the bill.) A motorcycle’s spinning wheels create gyroscopic effect that keeps the machine going straight. The more speed, the more gyro and the more stability. This is all good, unless you are racing. Most racers don’t give a hoot about straight-line stability: they’re happy to hold on like gorillas on the straights, just so long as the bike will turn left or right in the blink of an eye. And this is why all premier-class Grand Prix manufacturers – possibly for the first time in history – now run their engines backwards. It may also explain why Marc Márquez’s COTA and Argentina victories were so huge – bigger than any dry-track wins from last year. When an engine runs forward (like most streetbikes) its crankshaft rotates the same way as the wheels, thus adding to the gyro effect, which makes it more difficult to turn into a corner or change direction. The obvious way to reduce gyro effect is to reverse the direction of engine rotation, so the reverse-rotating crank reduces the total gyro effect created by the fast-spinning wheels. The beneficial effects on the dynamics of a motorcycle are significant: 2the bike will turn quicker and change direction faster; a huge consideration in modern racing when most racetracks are very tight and twisty. A reverse-rotating engine also reduces wheelies, because the crank’s torque reaction pushes the front wheel down during acceleration, rather than lifting it (although this is less important than in the days of two-strokes, when crankshaft inertia was greater.) However, nothing is for free in racing. If you run the engine backwards the engine needs an extra jackshaft to keep the rear wheel turning the right way. That shaft absorbs a significant amount of horsepower, as well as increasing engine weight and dimensions. In theory, a reverse-rotating crank also increases understeer in corners, making the bike run wide on the exit, which can prevent the rider from getting on the throttle. But presumably all these costs are worthwhile because this year Honda reversed the engine rotation of their RC213V, the first time they’ve run an engine backwards since the days of the 500s. The last time Honda went backwards was in 1987. The first NSR500, born in 1984, was a real handful, partly because its V4 two-stroke engine ran forwards. The torque reaction from the forward-rotating crankshaft lifted the front during acceleration, causing plenty of problems for riders who spent too much time fighting wheelies instead of thinking about the next corner. The NSR ran backwards from 1987 and won eight of the last 13 500cc titles."

A bit off topic and random but...

[adegnes]

[Frits Overmars]

Breezy, I agree with almost everything you wrote. But not this:

"my favourite natural phenomenon is gyroscopic effect. This is because we wouldn’t be able to ride motorcycles without it.

If you want to get to the bottom of this, click these links and watch the videos till the end.
http://bicycle.tudelft.nl/stablebicycle/
http://www.youtube.com/watch?v=YdtE3...yer_detailpage
http://www.youtube.com/watch?v=84Wcz...yer_detailpage

A bit off topic and random but...

I agree again. But there's an easy solution: it would be right on topic here: http://www.kiwibiker.co.nz/forums/sh...chassis/page56

[Drew]

"There’s very little ...."

A bit off topic and random but...

That's all very interesting, but ultimately incorrect.

What is actually happening to keep you upright, is a subtle weave from side to side. Faster ya go, the less weave is required.

The direction of rotation is of little consequence, the gyroscopic effect is the same.

Why spin the motor backwards then? Because it somewhat cancels the want of the bike to wheelie. For the front to come up, it now has to overcome the accelerating mass of the flywheel and crank, as well as the weight of the bike.