ESE's works engine tuner

[AndreasL]

Here are some sketches to go with that remark.
Attachment 319566

The radial approach apply to a single exhaust port as well, right?

If not, I have more adjustments to do.

[diesel pig]

Is this a snowmobile sprinter?

No I think it is a quad bike frame make for sprinting. I think the yanks call them sand dragsters.

[peewee]

Is this a snowmobile sprinter?

its a sand sprinter . i havent installed the swingarm and a-arms just yet

[peewee]

I think the yanks call them sand dragsters.

indeed that's what it is in yankee terms. I wanted to make some crankcases and use two ktm 250 or 300 cylinders but that's well beyond the budget. not to mention I wouldn't know where to start in designing them

[Frits Overmars]

The radial approach apply to a single exhaust port as well, right?

Right. But you should concentrate on that second picture (repeated below). The 20° difference between direction angle and position angle means that the outflow is not 100% radial, but this approach should give the optimum between maximum outflow and minimum duct volume.

[F5 Dave]

I've been out on my GG300 all day. A V twin of it would be a well useful engine.

[AndreasL]

Thanks Frits!

The "20* rule" was new to me and why I asked.
Will add it to the todo-list.

[dtenney]

Sent an email to your new email address. Did you get it?

[breezy]

looks like Ruaumoko is stamping his feet again... keep safe ..

[Niels Abildgaard]

I've been out on my GG300 all day. A V twin of it would be a well useful engine.

Jan and Frits has stated more than once that single cylinder two strokes are vibrating themselves to pieces.
The normal cure is a balance shaft that has some mass and eats some power.
As I read their sermons ultimate power from a twostroke is limited by blowdown time area.
If we make two halfsize cylinders the combined limitarea is 1.26 times as big.
The last 125 gave around 55 horsepower and one of the NSR500V 250 ccm cylinders around 80 horsepower and not 110 as one could suspect.
Two small give more than a single big.Surprice.
If the gg300 is nice a V twin with two 120 cylinders will drive just as nice ,be less mass,sound different and will not give driver chronic shaking.
A V2 90 degree twin with the two conrods side by side on a single crank throw have from birth a better balance as a fourcylinder fourstroke inline.
The argument that each cylinder must have sepparate crankchamber is maybe nonsense.When the pipes are doing their work it is surely not true.
This can be a very ligth and narrow engine if the two pipes can somehow be united to one system.Nobody has done it and gain is very beneficial for all mankind.One carb,one crank,two pistons and cylinders and one exhaust will also make unregulated aircraft engines better and safer.
Is there any law that says that buckets shall have one cylinder only?

[Flettner]

Jan and Frits has stated more than once that single cylinder two strokes are vibrating themselves to pieces.
The normal cure is a balance shaft that has some mass and eats some power.
As I read their sermons ultimate power from a twostroke is limited by blowdown time area.
If we make two halfsize cylinders the combined limitarea is 1.26 times as big.
The last 125 gave around 55 horsepower and one of the NSR500V 250 ccm cylinders around 80 horsepower and not 110 as one could suspect.
Two small give more than a single big.Surprice.
If the gg300 is nice a V twin with two 120 cylinders will drive just as nice ,be less mass,sound different and will not give driver chronic shaking.
A V2 90 degree twin with the two conrods side by side on a single crank throw have from birth a better balance as a fourcylinder fourstroke inline.
The argument that each cylinder must have sepparate crankchamber is maybe nonsense.When the pipes are doing their work it is surely not true.
This can be a very ligth and narrow engine if the two pipes can somehow be united to one system.Nobody has done it and gain is very beneficial for all mankind.One carb,one crank,two pistons and cylinders and one exhaust will also make unregulated aircraft engines better and safer.
Is there any law that says that buckets shall have one cylinder only?

No, just must be based on a road or trail engine. Not many 100cc twins around now, also will always be a parrallel twin at that. You may make a V twin but that would take some time and money, so far deemed not worth it. There have been twin cylinder buckets in the past (one had four pistons) and Suzuki twin engines used. I would like to see a tandem twin RV 100cc built, that might win a few dyno races I guess it boils down to time and money, no factory race teams here so the budget will ultimatly control the scope of develoment. Ideas are cheap
Dave, where were you riding the GG300? Aria?

[wobbly]

Got bored and decided to redesign the bypass thermostats I have used for years and just run out of.
They will fit all 2T bikes from 50 to 500cc and the bypass is set to start at 42*.
Up to this temp the water circulates from the pump,thru the cylinder and back to the pump,allowing the engine to get up to temp
on the warmup lap.
You can use the biggest rad you can fit and the temp stays at around 50*C with no tape in the coldest conditions., as the thermostat element cycles up and down
regulating the bypass flow.
I spent alot of time CAD designing the thing to make it real easy to CNC from stock bar, and it can be anodised any colour.
They still cost 200USD from RSC,and I reckon they are worth 1/2 that.
If interest is good enough I will get Flet to hoover up a bunch.

Also working on a speedshift sensor based on the Bazzaz unit as used on Superbike shift rods, with a proximity sensor that plugs straight into an Ignitech.
Those are 230E, and again I would say 1/2 that is reasonable.

[seattle smitty]

Shaking . . . heard a news item this morning, are you South Island guys all okay???

[F5 Dave]

The GG 3hundy will win no dyno day contests, it is pretty tardy in performance terms for a road racer. But a couple in a super light road bike with say 80hp with that lazy unstoppable spread.
Local moonshine ride. Roots tyres but close by.

[Bert]

No, just must be based on a road or trail engine. Not many 100cc twins around now, also will always be a parrallel twin at that. You may make a V twin but that would take some time and money, so far deemed not worth it. There have been twin cylinder buckets in the past (one had four pistons) and Suzuki twin engines used. I would like to see a tandem twin RV 100cc built, that might win a few dyno races I guess it boils down to time and money, no factory race teams here so the budget will ultimatly control the scope of develoment. Ideas are cheap
Dave, where were you riding the GG300? Aria?

Love to see a few more twin 100s they do sound great.
Here's Scotties twin (again) two MB50 barrels watercooled.

Got bored and decided to redesign the bypass thermostats I have used for years and just run out of.
They will fit all 2T bikes from 50 to 500cc and the bypass is set to start at 42*.
Up to this temp the water circulates from the pump,thru the cylinder and back to the pump,allowing the engine to get up to temp on the warmup lap.
You can use the biggest rad you can fit and the temp stays at around 50*C with no tape in the coldest conditions., as the thermostat element cycles up and down
regulating the bypass flow.
I spent alot of time CAD designing the thing to make it real easy to CNC from stock bar, and it can be anodised any colour.
They still cost 200USD from RSC,and I reckon they are worth 1/2 that.
If interest is good enough I will get Flet to hoover up a bunch.

Also working on a speedshift sensor based on the Bazzaz unit as used on Superbike shift rods, with a proximity sensor that plugs straight into an Ignitech.
Those are 230E, and again I would say 1/2 that is reasonable.

I'd be interested in both? Love my current bypass I purchased from you and have two other twostrokes...