ESE's works engine tuner

[wobbly]

The wasted spark has two compromises , firstly each plug only sees 1/2 the energy generated by the source coils , and secondly one spark jumps from ground to the electrode
the other one jumps from the electrode to ground to complete the circuit. ie one is reverse polarity causing missfires and power loss at high rpm/power levels..
Setting up two independant CDI's gives a huge increase in spark energy , and both are the same.
When making near on 100 RWHp its mandatory , the stock system simply didnt cope at all.

[F5 Dave]

Actually that's a good point. I never got around to buying separate coils for my RZ, must do that some time . . . along with a billion other things and 98.6hp is enough for the road.

[husaberg]

Other than the RDLC what 2 pot 2T bikes actually had a wasted spark std? i cant really think of any?

[katinas]

Other than the RDLC what 2 pot 2T bikes actually had a wasted spark std? i cant really think of any?

Same for other two parallel twins, Suzuki RG 250 and Kawasaki KR 1.
Once for RG 250 we adapted the old racing ignition with inner rotor (stator molded with blue plastic). Weaker spark and jetting became nightmare until, after two race, spark plug gap was reduced to 0,25 mm. From then works and revs fine, even on richer side.

[wobbly]

Same solution to Selettra on old Rotax 250 Tandem Twins. 1/2 the plug gap and it " functioned " just , when tuned properly.
This is where the R7376 plugs would have been a godsend , way less voltage required to ionise the gap.

[Niels Abildgaard]

The wasted spark has two compromises , firstly each plug only sees 1/2 the energy generated by the source coils , and secondly one spark jumps from ground to the electrode
the other one jumps from the electrode to ground to complete the circuit. ie one is reverse polarity causing missfires and power loss at high rpm/power levels..
Setting up two independant CDI's gives a huge increase in spark energy , and both are the same.
When making near on 100 RWHp its mandatory , the stock system simply didnt cope at all.

My BMW R25/3 single cylinder used a a cam on crank and worked very well(sometimes)
My Citroen Mehari (2CV engine) did the same and had a twin coil and worked well( when dry)
I have not imagined the japanese to be such cheapskaters and use one cam,coil and two plugs in series.
Thank You for a clear describtion of reason for and benefits of modifications.

[Niels Abildgaard]

Same for other two parallel twins, Suzuki RG 250 and Kawasaki KR 1.
Once for RG 250 we adapted the old racing ignition with inner rotor (stator molded with blue plastic). Weaker spark and jetting became nightmare until, after two race, spark plug gap was reduced to 0,25 mm. From then works and revs fine, even on richer side.

Thank You for a nice reading session on high power 2 pot 2 strokes 250-350 from the nineties.
I remember seing a Youtube of a RD350 tuner doing 170 km/h on rearwheel alone on a former east german airfield.
What was best V2 or inline 2?
My dream is to have been a rich man and had used life succesfully to prove that a common crankchamber 350 V2 could beat all competing 250 separate crankchambers on the serious values ,power,price,mass, external volume and vibrations
Will do next round on the circuit

[andreas]

Thank You for a nice reading session on high power 2 pot 2 strokes 250-350 from the nineties.
I remember seing a Youtube of a RD350 tuner doing 170 km/h on rearwheel alone on a former east german airfield.
What was best V2 or inline 2?
My dream is to have been a rich man and had used life succesfully to prove that a common crankchamber 350 V2 could beat all competing 250 separate crankchambers on the serious values ,power,price,mass, external volume and vibrations
Will do next round on the circuit

I remember talking to Ebbe at Eptune here in sweden, about a boxer 250 with joined crankcase project he had had high hopes for, but results were disapointing. The reason is best described by Frits, but basically the distribution of gas to each cylinder becomes uneaven and snowballs to the point where one is too starved to make any power.

[husaberg]

I remember talking to Ebbe at Eptune here in sweden, about a boxer 250 with joined crankcase project he had had high hopes for, but results were disapointing. The reason is best described by Frits, but basically the distribution of gas to each cylinder becomes uneaven and snowballs to the point where one is too starved to make any power.

Not to ever be so bold as to go against what frits has said, but as far as i am aware the Swissauto/Pulse/elf/MZ. etc etc was a shared case design i do not believe it was significantly lacking power. Wob would have some idea of what the output was as BSL leased one i believe.
it did appear it was constrained by the design but i don't think it lacked top end output for its cylinder design anyway
the one pic i seen of the upper crankcease looked like it was heavily shrouded to minimise the charge robbing though.ni believe this was absent on the later versions.


i think it was a bit over 100 deg v4

Same for other two parallel twins, Suzuki RG 250 and Kawasaki KR 1.
Once for RG 250 we adapted the old racing ignition with inner rotor (stator molded with blue plastic). Weaker spark and jetting became nightmare until, after two race, spark plug gap was reduced to 0,25 mm. From then works and revs fine, even on richer side.

Cheers for the info

[andreas]

In this configuration there would be a type of seal running on the middle crank web between the two cylinders that are closest, maybe this is what you refer to as "heavily shrouded". Are you sure this is not present in the examples you have given above?

[husaberg]

In this configuration there would be a type of seal running on the middle crank web between the two cylinders that are closest, maybe this is what you refer to as "heavily shrouded". Are you sure this is not present in the examples you have given above?

Positive have a look at the crank.... and the other picture. The shrouded are is where the conrod pokes through.
the two cylinders in the v share a case ,the seal seperates the parrallel cylinders which do not.
the pics are fuzzy but its the best i have sorry

here is a close up of the crank i think wob mentioned 10G

or read the text.

Click on atttachement three times.
the best seal version of what you are attempting to describe would be a ring sealed one was the french v twin Jean bb .... he did with the seal on a disc like a piston ring lab seal. first i seen of these was the DKW v3's

[Niels Abildgaard]

I remember talking to Ebbe at Eptune here in sweden, about a boxer 250 with joined crankcase project he had had high hopes for, but results were disapointing. The reason is best described by Frits, but basically the distribution of gas to each cylinder becomes uneaven and snowballs to the point where one is too starved to make any power.

Makes project even more tempting for my next life.
Two honourable experts claiming it cannot work.
Lovely when I succed.
Nuclear fission was first proven in Germany and Werner Heissenberg(Big Gun) calculated that it could not be selfsustaining(Big Bomb)
Normal aeroplane pratice was to make them stable in pitch.Along came F16 that is not pitch stable in the subsonic speed range and it is a well selling thing.
Some kind of squezing the transfer ports in the offending cylinder can maybe do the trick.According to Frits it takes 50 revs to reestablish resonnance after non ignition.
It dot need to react100% within one rev.

[Niels Abildgaard]

https://www.kiwibiker.co.nz/forums/a...9&d=1643897180

This is technology for separating crankchambers on Outboard two stroke V engines more or less.
Made in very big numbers
I dreamt of something lower mass for an aeroplane engine

https://www.homebuiltairplanes.com/f...-angels.32119/

[philou]

he seems to be very happy with it





http://www.2t-special.it/forum/viewt...hp?f=14&t=4378

[andreas]

Yes Husa, it seems to be as you say it is.