ESE's works engine tuner

[Rudex]

Steel valve + full ptfe inserts sounds like a good plan.
I saw considerable wear to both the carbon fiber valve, and 7022 alloy cover.
Made a wear surface in the cover from hardened steel(saw blade). Shortly after the disc exploded, probably softened/weakened by methanol.

I'm designing a new case and cylinder for the landspeed bike, easy to implement room for ptfe inserts.
Nothing experimental, shameless RSA copy, normal rotary valve intake.
Probably higher rpm than the norm, but most people seem to try to get power out of a 50 at idle speed.

Experimental and/or good-enough-for-testing-purposes does not work for actual racing. Who would've thought...

Attachment 354917

Molds will be 3d printed in sand and cast by Zalewatec in Germany.
Here's a little metal pouring trick on their Instagram:
https://www.instagram.com/reel/C4DZN...RsZTZjbGx0Zg==
Attachment 354918

A hand operated valve in the pouring basin, clever!

You should try this mod on cylinder and experiment.

https://www.kiwibiker.co.nz/forums/s...post1131221111

https://www.kiwibiker.co.nz/forums/s...post1131221113

Or you can do with insert 3d parts like you were doing.
Regards-

[adegnes]

You should try this mod on cylinder and experiment.

https://www.kiwibiker.co.nz/forums/s...post1131221111

https://www.kiwibiker.co.nz/forums/s...post1131221113

Or you can do with insert 3d parts like you were doing.
Regards-

So Rob has been playing with the trapped ring/huge port concept👍😊👍
I'm a few hundred pages behind, reading up as fast as I can!

[adegnes]

McMurray Tri-Mac Speedsters Supercharged 100cc opposed piston uniflow two stroke. Pretty cool!
Some info on the bike in my video from Bonneville.
Two opposing Honda 4t 50s with a custom cylinder in between, AMR300 blower, megaphone pipes.

Running mechanical injection, methanol/nitro. Had pump issues at the salt.

[Wos]

Steel valve + full ptfe inserts sounds like a good plan.
I saw considerable wear to both the carbon fiber valve, and 7022 alloy cover.
Made a wear surface in the cover from hardened steel(saw blade). Shortly after the disc exploded, probably softened/weakened by methanol.

I'm designing a new case and cylinder for the landspeed bike, easy to implement room for ptfe inserts.
Nothing experimental, shameless RSA copy, normal rotary valve intake.
Probably higher rpm than the norm, but most people seem to try to get power out of a 50 at idle speed.

Experimental and/or good-enough-for-testing-purposes does not work for actual racing. Who would've thought...

Attachment 354917

Molds will be 3d printed in sand and cast by Zalewatec in Germany.
Here's a little metal pouring trick on their Instagram:
https://www.instagram.com/reel/C4DZN...RsZTZjbGx0Zg==
Attachment 354918

A hand operated valve in the pouring basin, clever!

Hey Alex,

Maybe a paper air filter could help...dont know your configuration

Saw blades are made of HSS in most cases 😉

Very hard and wear ressistant material cause of tungsten or vanadium carbides in the matrix.

These carbides, seen under microsope, can built a rough surface...very hard small peaks standing out of surface...nearly impossible to polish well

I would choose a steel without... that is not forming carbides or nitrides...maybe rolled material...this is giving hard and elastic behaviour without carbon or hardening process

For example often feeler gauges are made of this Material 😉

https://www.hasberg-schneider.de/en/services/presision-thickness-gauge-strip-standard-dimensions/

Grüße Wolfgang

[wobbly]

Alex , I dont understand why you are sticking to the high Exhaust port floor concept.
The idea has been around for a while , but as I have stated before , to my knowledge no one has actually proven it works.
Jan lifted the floor 3mm on an RSA, and the dyno test was successful , and I have done the same on a TM KZ.
But his next experiment with it higher again , coincided with him retiring and the cylinder was machined back to stock before he left.

Thus you are flying in the dark - again.
Get the damn thing working perfectly as a somewhat conventional setup first I believe is the best approach.

At this point the Freetech 50 engines are light years ahead of you on petrol, and running reliably.
The other thing I noted somewhere is you said you were using C16 - this does not work well in a 2T.
It may have huge octane rating , but has minimal RVP - in fact in cold conditions it was found that the engines would not even start.
VP has a newer version that is specifically designed for 2T use.

[adegnes]

Alex , I dont understand why you are sticking to the high Exhaust port floor concept.
The idea has been around for a while , but as I have stated before , to my knowledge no one has actually proven it works.
Jan lifted the floor 3mm on an RSA, and the dyno test was successful , and I have done the same on a TM KZ.
But his next experiment with it higher again , coincided with him retiring and the cylinder was machined back to stock before he left.

Thus you are flying in the dark - again.
Get the damn thing working perfectly as a somewhat conventional setup first I believe is the best approach.

At this point the Freetech 50 engines are light years ahead of you on petrol, and running reliably.
The other thing I noted somewhere is you said you were using C16 - this does not work well in a 2T.
It may have huge octane rating , but has minimal RVP - in fact in cold conditions it was found that the engines would not even start.
VP has a newer version that is specifically designed for 2T use.

The picture is misleading wobbly. Exhaust duct floor is sitting just 1.5mm above bdc. I've gone 95% RSA copy, pretty much the only difference is duct exit which is reduced to same area as blowdown, 76% of total effective area in this case.
I'm keeping ludicrous experimental stuff out of this engine.


Was running c12 at Bonneville before switching to methanol/nitro. Would've been clever to switch out for something unleaded and highly oxygenated probably.
At home I've been running sunoco supreme.

I'll study fuel, thanks for the heads up!

[adegnes]

Renderings of the new engine.
RSA ports/ducts(more likely RSW, took measurements from drawings I could find on here and in what Frits sent me a while back). Exhaust floor 1.5mm above BDC.
Exhaust duct exit reduced to effective blowdown area, will have a transition in the flange spigot.
Cooling inside and over transfers, then under ex duct, over ex duct and into the head. Hopefully I can get the 3d printed sand out of there.

Least insane design so far😁

[wobbly]

I have done a huge amount of testing around the Aux ducts and the entry to the main.
The floor should exit perpendicular to the bore then radius down as a ski jump.
The roof should go the other way , forming an area pinch point exactly where the side ducts enter.
This reduces the area change where the side ducts add into the main port , and anything shorter or longer than 12mm with the Aux septum looses power.

[F5 Dave]

Those measurements were a 125 yeah. so could he assume a 50 would scale down a touch? Obviously that would make his model worse still. At some point there needs to be metal enough to absorb the heat evenly. I guess thermodynamics care little about convenient scaling.

[adegnes]

Those measurements were a 125 yeah. so could he assume a 50 would scale down a touch? Obviously that would make his model worse still. At some point there needs to be metal enough to absorb the heat evenly. I guess thermodynamics care little about convenient scaling.

👍 Damn you thermodynamics!

I have done a huge amount of testing around the Aux ducts and the entry to the main.
The floor should exit perpendicular to the bore then radius down as a ski jump.
The roof should go the other way , forming an area pinch point exactly where the side ducts enter.
This reduces the area change where the side ducts add into the main port , and anything shorter or longer than 12mm with the Aux septum looses power.

Thanks for the advice! I'll get to work!

[Tim Ey]

Dont be too optimistic with the bridge thickness in casting. Either make them thicker in the addition that you will put on, or make them wider and grind them to suit.

What timings are you aiming for? I doubt that you will need ridiculous high timings for a peak at reasonable rpm.

[adegnes]

Dont be too optimistic with the bridge thickness in casting. Either make them thicker in the addition that you will put on, or make them wider and grind them to suit.

What timings are you aiming for? I doubt that you will need ridiculous high timings for a peak at reasonable rpm.

Crossing fingers! There's 3mm added to the bore in the model for casting.
I managed to successfully cast cylinders with the same bridge thickness at home. Did take me 6 tries , but was my first ever experience with casting.
Lost pla, sand/plaster mix.
Zalewatec thought it would cast well.

198ex + a little bevel
130A
132B/C
90mm rod, 39.3mm stroke.
STA matched in Engmod, lots of area.

Working on the pipe, I am looking for relatively reasonable rpm.

[ken seeber]

Alex,

Re your concerns re possible frictional drag of the disk valve. I agree with others (Wos) that this might be small, given the right material matching. However, I am aware of these breaking (in karts) occasionally and your experience.

So, how about eliminating the friction entirely? Instead of allowing the valve to “float” axially within the valve housing (presumably bearing on either side of the valve depending on the pressure differential between the crankcase and the intake system), fix the valve to the crankshaft so it cannot move axially. Then adjust the side clearances between the disk and the cover, such that the disk cannot contact (drag) the cover. Obviously to do this will require allowance for crank float and thermal expansion of the cases etc. To make you feel better, a more solid disk, eg 2 mm steel to remove and doubt about bending.

Yes, yes, I know there will be leakage, loss of sharp timing and maybe even hard to start etc, but does this matter? Remember 24/7 induction, open all the time, making any such leakage relatively minor.

Keep up the 2 stroke passion.

[Wos]

Alex,

Re your concerns re possible frictional drag of the disk valve. I agree with others (Wos) that this might be small, given the right material matching. However, I am aware of these breaking (in karts) occasionally and your experience.

So, how about eliminating the friction entirely? Instead of allowing the valve to “float” axially within the valve housing (presumably bearing on either side of the valve depending on the pressure differential between the crankcase and the intake system), fix the valve to the crankshaft so it cannot move axially. Then adjust the side clearances between the disk and the cover, such that the disk cannot contact (drag) the cover. Obviously to do this will require allowance for crank float and thermal expansion of the cases etc. To make you feel better, a more solid disk, eg 2 mm steel to remove and doubt about bending.

Yes, yes, I know there will be leakage, loss of sharp timing and maybe even hard to start etc, but does this matter? Remember 24/7 induction, open all the time, making any such leakage relatively minor.

Keep up the 2 stroke passion.

Good idea 😉 worth to think... a 2 mm stiff disc out of titanium

Calculate max axial forces given at inlet by max pressure Differenz and max forces from moving mass of gases...

Maybe a physicist could do that 😀

Find max bending of titanium valve disc at these forces...do minimum possible spacing

[Tim Ey]

Crossing fingers! There's 3mm added to the bore in the model for casting.

In radius or diameter? In diameter it is not enough. I did the same and needed to weld.

198ex + a little bevel
130A
132B/C
90mm rod, 39.3mm stroke.
STA matched in Engmod, lots of area.
.

Matched sta or real study?
Since those are the RSA timings, I would think it will behave well at the same pistonspeed. That would be 17000rpm...

I think I would rather start at
A 126
B/C 124
MAIN 193
AUX 178
With a peak at 14500 and overrev to 16000

Grinding higher is easier than grinding down.