Ke125

[cotswold]

Well the power just keeps building, what to do?

Stop before it becomes addictive

[prorad]

ill bite why no pictures of the lc cooled one.
Jason has one its on his avatar so why is yours soooo secret?
One of the most successful tuners of production racers in the 50-60s in the UK use to put his wheels offset on purpose, but still in line with each other as they steered better that way. Sid Lawton. Can't remember why?

The wheels were in line! I worked for Syd Lawton at the time, and was involved in sorting the problem out. Syd discovered a discrepancy in hands off steering, when the bike would veer to one side. Measured up in the workshop we found the wheels were parallel but not on the same centre lines. The decision was made to adjust the spokes to pull the rims over. The error was corrected by splitting the difference between the two wheels, i.e pulling the front rim to the left, and the rear to the right. The total error was in the region of 1/8 inch.

[husaberg]

The wheels were in line! I worked for Syd Lawton at the time, and was involved in sorting the problem out. Syd discovered a discrepancy in hands off steering, when the bike would veer to one side. Measured up in the workshop we found the wheels were parallel but not on the same centre lines. The decision was made to adjust the spokes to pull the rims over. The error was corrected by splitting the difference between the two wheels, i.e pulling the front rim to the left, and the rear to the right. The total error was in the region of 1/8 inch.

I will bow to your Superior knowledge.......

in my defense i wasn't of course suggesting the wheel weren't inline with each other when modded but offset from the centerline to improve the steering (likely because the Triumph engine has a lot of heavy spinning things Clutch sprockets chain etc on one side. Can you confirm this?

[kel]

Well I have to admit the motors output is everything I hoped for, and in all honesty what I expected.
The motor design was based on time angle area calculations. Time angle area sets the foundation for how well the motor will breathe and enables matching of port timings. Jennings proposed time angle area back in the early seventies (possibly earlier) but missed blowdown area. The concept of blowdown area was introduced by Blair, at least it was Blairs book "design and simulation of 2 stroke engines" that brought this to my attention. The first dyno run with the KERS was done with a reserved inlet timing in the hope of adding some midrange punch that would benefit kart track racing, it didnt! So I went back to the maths and set the timing to match the other ports. The calculations used for this motor suggested 32 crank hp at 11k, I assumed 15% loses which would be 27.2 rear wheel hp and we have 27.3 at 11.5k.
Of course its not as simple as just time angle area. We are incredibly fortunate with the internet age to have access to fantastic 2 stroke minds such as Jan Thiel, Frits Overmars, Wobbly, etc, etc and of course all the learnings of the ESE boys made available through the epic ESE thread. With the input and advice of these fantastic people it becomes possible for almost anyone to modify something as basic as a farm bike into a (modestly) high power 2 stroke motor. A dyno and an experienced operator helps too .
Big thanks to everyone that has helped both directly and indirectly to deliver this motor, especially TZ350 : Now to get it on to the track

[Bert]

Well I have to admit the motors output is everything I hoped for, and in all honesty what I expected.
The motor design was based on time angle area calculations. Time angle area sets the foundation for how well the motor will breathe and enables matching of port timings. Jennings proposed time angle area back in the early seventies (possibly earlier) but missed blowdown area. The concept of blowdown area was introduced by Blair, at least it was Blairs book "design and simulation of 2 stroke engines" that brought this to my attention. The first dyno run with the KERS was done with a reserved inlet timing in the hope of adding some midrange punch that would benefit kart track racing, it didnt! So I went back to the maths and set the timing to match the other ports. The calculations used for this motor suggested 32 crank hp at 11k, I assumed 15% loses which would be 27.2 rear wheel hp and we have 27.3 at 11.5k.
Of course its not as simple as just time angle area. We are incredibly fortunate with the internet age to have access to fantastic 2 stroke minds such as Jan Thiel, Frits Overmars, Wobbly, etc, etc and of course all the learnings of the ESE boys made available through the epic ESE thread. With the input and advice of these fantastic people it becomes possible for almost anyone to modify something as basic as a farm bike into a (modestly) high power 2 stroke motor. A dyno and an experienced operator helps too .
Big thanks to everyone that has helped both directly and indirectly to deliver this motor, especially TZ350 : Now to get it on to the track

Well done Kel (and the rest of the people behind the scene).
Very impressive and I can't wait to see this out on the track.

[Buckets4Me]

Well the power just keeps building, what to do?

so a new Beast is born this one looks tame and friendly ish

[chrisc]

Nice one kel and co! I'm very much looking forward to seeing this run soon

[kel]

this one looks tame and friendly ish

I dont know about friendly but the tame manner in which the power is made is due to peak torque occuring 2000rpm before peak hp, the falling torque curve should make for a very useable motor. Funny thing is its a result of one of the last "just get it built" compromises. The head has a wide squish and a deep (by todays standards) combustion chamber. It was planned to have this welded up and re-machined but I like the result so much I think I'll leave it. Maybe we'll build a corrected head for faster tracks.
We have added another 500rpm over rev through power jet adjustment, it now hits the rev limiter while still making good hp.
Im finished with the motor until after the GP, it maybe running rich but 27+ hp with a 4.5k spread should be enough to scare a few 4 strokes (Im not even going to mention the weight advantage of bike and rider)

[jasonu]

I dont know about friendly but the tame manner in which the power is made is due to peak torque occuring 2000rpm before peak hp, the falling torque curve should make for a very useable motor. Funny thing is its a result of one of the last "just get it built" compromises. The head has a wide squish and a deep (by todays standards) combustion chamber. It was planned to have this welded up and re-machined but I like the result so much I think I'll leave it. Maybe we'll build a corrected head for faster tracks.
We have added another 500rpm over rev through power jet adjustment, it now hits the rev limiter while still making good hp.
Im finished with the motor until after the GP, it maybe running rich but 27+ hp with a 4.5k spread should be enough to scare a few 4 strokes (Im not even going to mention the weight advantage of bike and rider)

How about a few pictures.

[kel]

How about a few pictures.

do you mean dyno graph pic? Was a page back. Dont have a copy of the later runs.



The bike itself isnt overly pretty to look at, not a matching colour to be found

[Rick 52]

Congratulation Kel, that is fantastic! All that hard work is going to bring you some big smiles once on the track..

[F5 Dave]

You don't know how depressing this is. To get this straight away is phenomenal. Good work you bstd!

[jasonu]

do you mean dyno graph pic? Was a page back. Dont have a copy of the later runs.

No I was refering to pix of the actual bike.
What carb are you using?

[kel]

Shortened and taper bored OKO 24mm with power jet. Still needs the adjustable air correction mod but seems to work OK.

[kel]

How about a few pictures.

Here you go.
Have added riser clip on bars to try and lessen the pressure on the wrist