ESE's works engine tuner

[seattle smitty]

Thanks, Frits; I'll try it. I'll see if I can delete it here (Adegnes, I don't understand what you're trying to tell me).

[2005bully]

https://www.youtube.com/watch?v=AF9nBjgcX3E

The "canoe" in the video appears to be a Taiwan Long Boat.... I have talked to individuals that race these things in Taiwan. Was told its a sport that is kind of off the charts, strictly amateur, but finding huge popularity in some regions. Below is a link with a little more info.

http://www.john-tom.com/Klong16/LongTail.html

Kermit Buller

[Peiter]

Hi guys,

after reading this thread almost daily for more than half a year and seeing so many interesting projects, I really thought I should start sharing my project with you instead of just reading and not contributing .
However, I really don't know where to start so I'll just drop into the middle of it. Together with a friend (who is the driver), we compete in the dutch 150m dragracing / sprint championship 70cc shifter class.

The bike was originally a 2007 derbi GPR which we modified to make it lighter and more powerful. Currently, the weight is at about 47 kg with approximately 27 - 27.5 hp and we are doing the 150m from a stand still in 6.71 seconds.
For next year however, we would like to go faster, therefore (and to learn more about 2 strokes), we are in the process of making our own cylinder.
I have made multiple silicone prints of the transfers and exhaust of a honda 125 a-kit and an RSA and tried to mix it all up with the comments from Frits and Wobbly.
The cylinder has been drawn in a CAD program and 3D printed in PLA after which it was cast in aluminum by using investment casting. At this moment I am machining the raw cast piece and making an adapter plate / head inserts, etc.

For now I think this is enough before my post becomes confusing. In the attachments I have posted a picture of the bike, the cylinder, its mold and the cylinder during the investment casting process and the power curve

cheers,

Peter

[jonny quest]

^^ very cool! ^^

[adegnes]

Hi guys,

after reading this thread almost daily for more than half a year and seeing so many interesting projects, I really thought I should start sharing my project with you instead of just reading and not contributing .
However, I really don't know where to start so I'll just drop into the middle of it. Together with a friend (who is the driver), we compete in the dutch 150m dragracing / sprint championship 70cc shifter class.

The bike was originally a 2007 derbi GPR which we modified to make it lighter and more powerful. Currently, the weight is at about 47 kg with approximately 27 - 27.5 hp and we are doing the 150m from a stand still in 6.71 seconds.
For next year however, we would like to go faster, therefore (and to learn more about 2 strokes), we are in the process of making our own cylinder.
I have made multiple silicone prints of the transfers and exhaust of a honda 125 a-kit and an RSA and tried to mix it all up with the comments from Frits and Wobbly.
The cylinder has been drawn in a CAD program and 3D printed in PLA after which it was cast in aluminum by using investment casting. At this moment I am machining the raw cast piece and making an adapter plate / head inserts, etc.

For now I think this is enough before my post becomes confusing. In the attachments I have posted a picture of the bike, the cylinder, its mold and the cylinder during the investment casting process and the power curve

cheers,

Peter

^^ very cool! ^^

Second that! Great job, looks mean!
I love purpose built no compromise stuff almost as much as frankenbikes!
What's the tape on the front rim for? Aerodynamics?

[jonny quest]

I saw that tape, and wondered the same. ... but really curious as to why you installed drum brakes? Less weight?

[Peiter]

Thanks guys!

Actually Adegnes, years ago the competition started out as street mopeds / buckets.
However, the compitition has progressed and because I'm a mechanical engineer, I love to make strength and weight calculations to gain every possible ounce :d.

The tape in the front wheel is to ensure the optical sensors don't shine through the wheel at the start.
The time registration system was build for original tires which were much higher, therefore the system doesn't cope well with our wheel .

Here is a movie of a test drive
https://www.facebook.com/sprintperfo...type=2&theater

Peter

[MotleyCrue]

On the Ryger maybe its not high crankcase compression at all, maybe there is no crankcase compression. Firing off a 2 stroke with no crankcase compression is not a problem with just a simple addition, and running in the powerband with no crankcase compression is possible (24/7).

But idling with no crankcase compression and a normal 2 stroke exhaust I'm not sure that would work, I'm guessing it wouldn't, but I never tried it. I bet there is a way to do it though. More thought required.

[breezy]

Bosch aux coolant pump found in many Mercs and VWs pumps 25l/min unrestricted @12v, about 1-1.5amp - not bad at all. Don't know how much juice it can handle, but 15v should work, maybe more.

Good call adegnes. theres one on its way to me... had heard of people using the merc window washer motor and bottle. but the auxiliary coolant pump should be better.. thanks.

[TZ350]

Page 1310 .....

After reading some of the content in the ESE thread, I've become really inspired to take a closer look at hydroforming chambers.

Continuing the celebration of other peoples home built bikes.



Kel

Slow progress going on here, but progress none the less.
Crank has been rebuilt (thanks Rob for your time and patience). Unfortunately I ended up having to use the same length rod that was being used previously as the longer genuine Yamaha rod had no slots at the big end, WTF. So the trusty TKRJ 100mm rod has gone back in but with an RGV flat cage big end bearing.

Coated piston is back.
Attachment 309480
Cost $97 for coating to skirt and ceramic coating to crown. Turns out all that's need for the squish band mask is the heavy type of vinyl that sign writers use, oh well we know for next time.

One of the problems with getting real power out of the KE is the inlet area, i.e. the rotary disc is too small.
Attachment 309481
Seems we have solved the problem.
Attachment 309482
Its a custom disc made to the max size for the original disc cover!
The Oring of the disc cover will need to be machined out meaning sealing will just be from sealant around the outer edge of the cover which isn't ideal.
Attachment 309483
Attachment 309484
The mod is worth an extra couple of horsepower, or more to the point the inlet time area can now match the rest of the motors timing.
Still some more grinding to do in the cases but Im getting there.

p.s. This is buckets as it should be; epoxy, grinding, bouncing around ideas with your mates, and some back yard engineering. Not a bolt up kit part to be found.

I've been working hard at trying to manage the motors heat. Wrapped the exhaust, added a 2mm copper spacer under the barrel (replacing the ali one) and formed it into a cylinder shroud. Sand blasted cylinder, head and cases and applied a very thin coat of flat black. Insulated under the fuel tank and the fuel lines and added a ram air to the air box (this added 1hp on the dyno with the fans feeding it).
I grabbed a thermal imaging camera from work to log the race temp and hopefully get some shots/info from the other air cooled 2 strokes
Took the bike to the track and it ran like a pig, a quick jaunt over to team head quarters and all fixed (thanks Rob ) Managed to get back to the track to get a couple of races in but pretty much forgot about the camera

The one lot of photos I took were after a practice session, head temp of 96 degrees
Attachment 293451

So the jury is out on whether all the work has been worth while but the bike was embarrassingly fast and survived a very hot afternoon without drama.

[F5 Dave]

Thanks guys!

Actually Adegnes, years ago the competition started out as street mopeds / buckets.
However, the compitition has progressed and because I'm a mechanical engineer, I love to make strength and weight calculations to gain every possible ounce :d.

The tape in the front wheel is to ensure the optical sensors don't shine through the wheel at the start.
The time registration system was build for original tires which were much higher, therefore the system doesn't cope well with our wheel .

Here is a movie of a test drive
https://www.facebook.com/sprintperfo...type=2&theater

Peter

That is like super iimpressive.

[jonny quest]

I saw that tape, and wondered the same. ... but really curious as to why you installed drum brakes? Less weight?

[Flettner]

On the Ryger maybe its not high crankcase compression at all, maybe there is no crankcase compression. Firing off a 2 stroke with no crankcase compression is not a problem with just a simple addition, and running in the powerband with no crankcase compression is possible (24/7).

But idling with no crankcase compression and a normal 2 stroke exhaust I'm not sure that would work, I'm guessing it wouldn't, but I never tried it. I bet there is a way to do it though. More thought required.

I believe there is a twostroke Kart engine in Perth (you know, Australia) that will sart and run with no crank case.

[MotleyCrue]

I believe there is a twostroke Kart engine in Perth (you know, Australia) that will sart and run with no crank case.

Cool. Anyone have a link or know anything specific about it. Is it competitive?

[TZ350]

Attachment 313908Attachment 313909Attachment 313910Attachment 313905Attachment 313906Attachment 313907

A “ROUGH AS GUTS” EXPERIMENT Part 1

The question is, what happens when you:
1. Get a 100 cc ARC piston port kart engine, essentially very similar and with many interchangeable parts with the Yamaha KT100S kart engine, and connect an A port to atmosphere via a filled in passage to a flanged face. Height of the port is unchanged from the original engine.
2. However, when at TDC, there is a direct passage (something we don’t want, do we?) to the crankcase via the cut-out in the side of a regular piston
3. So we weld a small piece into this side of the piston to block it off and while we are there we’ll drill a series of holes into the rear of piston to vent thru the open piston port inlet so there’ll be no great pressure fluctuations in the crankcase


Part 2 coming

Attachment 313911Attachment 313912Attachment 313913Attachment 313914


A “ROUGH AS GUTS” EXPERIMENT Part 2

4. So there’s no influence due to extraneous cylinder connected volumes in the upper cavities of the blocked off transfer passages (1 * A & 2 * B), we fill these flush with Silastic
5. Then we bolt it all together with a carb, but with no exhaust system
6. Crank it over with a few squirts of oil into the crankcase, check it out and it is all nice and oily, as one would expect with a wet sump.
7. Fill the carb with fuel only (no oil), ignition on and crank it over.

Simple really and I did say “rough as guts”.

WODDAEWESREKKON happens then?

If you keep that direct passage, the transfer windows can double as piston controlled inlet ports and you could feed a rear transfer port from the crankcase.
But since you don't want that, I assume that you wanted to completely exclude the crankcase from the mixture flow. I then also assume that there's a puddle of oil in the crankcase to keep the bearings happy. EDIT: only now did I see your second post: a puddle it is.What's wrong with pressure fluctuations in the crankcase? The built-up pressure that tries to prevent the piston from moving down, will be helping it again on the way up. I anticipate a lot of pumping losses and a lot of oil mist escaping through those drilled holes.
To comfort you, here's a picture to show you that you're not the only one suffering from ludicrous ideas .
Attachment 313915

I think these are the posts.

Here is good search function using google, originally posted in ESE thread 749 page

Follow Muciek's link to Seattle Smittys thread on how to data mine the ESE thread for all the good info.