ESE's works engine tuner

[Flettner]

I'm thinking the oil will arrive via the fuel and be deposited on the cylinder wall, like normal. Remember, the sleeve is open ended and slides down, completely past the exhaust ports, uncovering the alloy cyinder wall as transfer / exhaust is taking place. Also the transfer windows will slide up toward the exhaust port, helping deposit oil residue under the exhaust port. As the chamber ( x2 ) stuffs fuel air back into the cylinder, the sleeve is closing. This too will deposit oil directly onto the outer sleeve wall. Who knows? I'm sure WE will find out. Oil is not what worries me, it's the heat distortion. Thats why I've water cooled eveywhere around the exhaust ports and outlet tubes. Fuel might have to be the sleeve's saviour, that fuel might end up being E85?

[TZ350]

I am stuck with a long inlet manifold of about 90 mm along center line, which curves about 35* What would be better for power: shorter & more curved or longer and straighter? Should the cross sectional area remain the same all the way through? I'm allowed any carb

Just putting a few ideas out there.



A pumper carb can be smaller than a regular carb.



If you have a problem with space, a pumper can be mounted at any angle you like, even verticaly up or down.



I picked up usefull hp by reducing the flow restriction in the curved part of the inlet manifold with a divider.

Because of the restrictive 24mm carb rule I have to work with, my manifold was bigger at the exit than the inlet.



Hopefully the pictures show how a divider promotes better air flow. Its an idea I intend on trying in the transfer ducts at some point.

I am not sure the tapering down inlet idea that works so well in four strokes applies to 2T's. A pipe that diverges at 1 deg included flows more than a parallel pipe.

I think that a divergent inlet that allows for some pressure recovery might be worth looking at. Its a question I am very interested in too, it would be interesting to hear Wobs and Frits's thoughts about inlet taper for a 2T.

[DaisyB]

Thanks TeeZee,

I can't work out how to copy bits of posts - too early in the morning (for me).

I can't directly bolt on a tillotson as the frame rail (about 80mm dia) is within 40mm of the barrel at the inlet port but the divider is a good idea & the new barrel has a bridge already. If my manifold has the divider sticking into the port they could meet & I'm not adding metal to the barrel !

Re Injection, I've got a Vespa at the workshop with Ecotrons injection fitted and not running It's been looking at me every time I go down there for over a year, I just don't have the computing/electronics skills and not enough time to learn at the moment. Still, reading the last few pages has given me some pointers

[DaisyB]

Oh look, there's a "reply with quote" button

How close to the carb does the flow divider go? Or is it just on the curved section?

[husaberg]

Thanks TeeZee,

I can't work out how to copy bits of posts - too early in the morning (for me).

reply with Quote and then copy out the quote by, and the end of the quote bits. Just keep adding them

[QUOTE=DaiyB;113061927]it will look like this[/QUTE] until you reply

I can't directly bolt on a tillotson as the frame rail (about 80mm dia) is within 40mm of the barrel at the inlet port but the divider is a good idea & the new barrel has a bridge already. If my manifold has the divider sticking into the port they could meet & I'm not adding metal to the barrel !

Clever Rob Muzzy used to do the same with carb reducing sleeves for the ZXR750's he had them as part of the manifold as he wasn't allow to mod the carbs for WSBK on tighter tracks.

[TZ350]

How close to the carb does the flow divider go? Or is it just on the curved section?

The flow divider was just in the curved section.

I can't directly bolt on a Tillotson as the frame rail (about 80mm dia) is within 40mm of the barrel at the inlet port but the divider is a good idea & the new barrel has a bridge already. If my manifold has the divider sticking into the port they could meet & I'm not adding metal to the barrel !

Good thinking, I am impressed, yes with a divider poking inside the barrel your not actually adding metal to the barrel, I like it.

I am hoping this V Tech inlet idea will add an extra 1000 or so rpm on the bottom end

The plan is to run it up with the valve fully open then fully closed, compare the graphs and manually switch it during a run to see what a dual curve looks like. I am ready to go, just need to get to the dyno.

Attachment 239753

Interesting, in the hand activated trial of the V Tec there is the beginings of some extra power at the top. Not sure what contributed this, the vetec added an extra 25mm to the inlet tract for 195mm total or possibly the little kick I gave the end of the divider better directs the flow behind the conrod as the incoming air/fuel enters the crank case.

This is something else we tried, it was for halving the diameter of the inlet tract so as to keep the air velocity and ramming effect at lower rpm. It worked but was a lot of effort for 500 rpm between 6500 and 7000 rpm.



Your idea of poking a divider inside the barrel could be extended to the exhaust port. If you are brave enough you could machine a bolt in alloy divider with a plated edge for the ring to run on, and fit it into the exhaust port and that way you could really widen the port out to get the required blow down time area with a lower exhaust port timing that better suits the natural resonance of tuned exhaust systems ie 192 - 196 degrees duration.

Re Injection, I've got a Vespa at the workshop with Ecotrons injection fitted and not running It's been looking at me every time I go down there for over a year, I just don't have the computing/electronics skills and not enough time to learn at the moment. Still, reading the last few pages has given me some pointers

Ecotrons emailed me today and are interested in supporting me as they have seen I am very keen on their EFI unit and have the facilities to develop and test a performance 2T system on my bike.

I am the ideal crash test dummy for them as I started of knowing nothing and are falling into every trap along the way. I will keep posting as I go along, hopefully some usefull tips will come out of it.

[wobbly]

Just a silly question but one that has worked several times to great effect on quads etc, can you simply reverse the scooter cylinder 180*
on the studs.
This may help the inlet, but make the pipe even more of a nightmare than already

[F5 Dave]

Your idea of poking a divider inside the barrel could be extended to the exhaust port. If you are brave enough you could machine a bolt in alloy divider with a plated edge for the ring to run on, and fit it into the exhaust port and that way you could really widen the port out to get the required blow down time area with a lower exhaust port timing that better suits the natural resonance of tuned exhaust systems ie 192 - 196 degrees duration.. . .

I think you would have to be more than brave. It would work well as long as that bit of the engine didn't get too hot. Even with a thick slice of ally there is no way it could shed heat, it would just have to budge & there would always be a lip at the top of the port for the ring to traverse.

I do like the inlet idea though. You can see the tech inspector going "Hey that's not. . .um. . .well. . . Yeah ok, good one"

[TZ350]

I think you would have to be more than brave. It would work well as long as that bit of the engine didn't get too hot. Even with a thick slice of ally there is no way it could shed heat, it would just have to budge & there would always be a lip at the top of the port for the ring to traverse.

I do like the inlet idea though. You can see the tech inspector going "Hey that's not. . .um. . .well. . . Yeah ok, good one"

"Hey that's not. . .um. . .well. . . Yeah ok, good one" don't you just love that when it happens.



Relieve the bridge so when it bulges out, it does not bulge into the bore enough to rub the piston, also extend the bridge insert above and below the port edge so that the ring does not catch.

Wish I had thought of this before, it could have been the answer for the GP.

[F5 Dave]

Its such a long ugly heatpath. If you could get a mouse size welder in there then it would be a winner hands down.

[TZ350]

Welding is out, as DaisyB is not allowed to add any metal to his cylinder (He can only bolt bits onto it).

[F5 Dave]

Hmm, and at the point it was interference fit I would claim it had indeed been 'added' to it.

If it was sliding fit & ideally attached to the exh then it is part of the exhaust.

[Ocean1]

Hmm, and at the point it was interference fit I would claim it had indeed been 'added' to it.

If it was sliding fit & ideally attached to the exh then it is part of the exhaust.

http://www.engineeringtoolbox.com/th...als-d_859.html

Done carefully you could extract it for inspection with your fingers.

And have it a rock solid interference fit at operating temp.

Edit: depending on the port shape and wall thickness...

[Yow Ling]

Welding is out, as DaisyB is not allowed to add any metal to his cylinder (He can only bolt bits onto it).

Could you melt it down and recast it from the same metal, not adding metal

[husaberg]

Could you melt it down and recast it from the same metal, not adding metal

he could also let it oxidise in areas where it could be beneficial to performance