ESE's works engine tuner

[jbiplane]

Thik it could be interesting for local comunity?

[SwePatrick]

Well,, I got my TRD250 engine at home finally.
It is an object, not worthy taking pics on yet, rust and corrosion everywhere, but salvagable.

I got this question thou, is it possible that any YZ125 cylinder might fit on it?
The engine is an 1KT/2MA.

Rgds
Patrick

[F5 Dave]

The YZ barrel with no cast in liner of course is small and light. If you don't have the carbs fitted to the TDR engine it should fit just nicely above the gearbox area with little chance of falling off.
No problem, thank me later.

[SwePatrick]

I was looking at -93 YZ cylinders, they had the same bore stroke.
And topdeck surface looks very similar as the TDR heads surface.

They got as std 56/50 bore/stroke
As my classrules says max 212cc i´m thinking about put thicker liners in them and run 50/50 bore/stroke and get ~196cc and a lot of material to bore if needed.

[husaberg]

I was looking at -93 YZ cylinders, they had the same bore stroke.
And topdeck surface looks very similar as the TDR heads surface.

They got as std 56/50 bore/stroke
As my classrules says max 212cc i´m thinking about put thicker liners in them and run 50/50 bore/stroke and get ~196cc and a lot of material to bore if needed.

There was a 400cc TZR 1kt done with DT200 Cylinders and a stroked crank
A lot of work to get it all to fit esp te heads the best cylinders to use are WR200 as they are supposed to be triple EX port.

https://www.kiwibiker.co.nz/forums/s...post1130346885
https://www.kiwibiker.co.nz/forums/s...-tuner/page550

[SwePatrick]

Yes,, but i cant have above 212cc total

[husaberg]

Well,, I got my TRD250 engine at home finally.
It is an object, not worthy taking pics on yet, rust and corrosion everywhere, but salvagable.

I got this question thou, is it possible that any YZ125 cylinder might fit on it?
The engine is an 1KT/2MA.

Rgds
Patrick

Yes,, but i cant have above 212cc total

Okay it was a bit unclear, so why choose a 2 cylinder 250cc engine? and then have to destroke or sleeve 2 cylinders.
If its a 200cc engine in total and you want it to be a twin, i would sugest following TZ350 lead in destroking like he did with his GPNSR100, not ideal, but far less costly mods.
ie no sleeve and replate x2

[SwePatrick]

I´ve got THIS engine now, i won´t buy a totally other one, let´s make the best of what i´ve got.
And i find it very good(and easy) to go down in bore size and make it square.

I have also destroked a KX250 engine with some good results, but i want to test a new way.

[TZ350]

.
One advantage of de stroking a two stroke engine is that it automatically increases the blow-down-time-area for extra power and rpm without having to do any porting to the cylinder.

Shortening the stroke means the crank will rotate through more crank angle degrees going from exhaust opening to transfer opening.

[lodgernz]

.
One advantage of de stroking a two stroke engine is that it automatically increases the blow-down-time-area for extra power and rpm without having to do any porting to the cylinder.

Shortening the stroke means the crank will rotate through more crank angle degrees going from exhaust opening to transfer opening.

No porting...except bringing the exhaust port(s) and the transfers closer together to compensate for the shorter stroke.
Oh wait...that will reduce the blowdown STA...

[SwePatrick]

.
One advantage of de stroking a two stroke engine is that it automatically increases the blow-down-time-area for extra power and rpm without having to do any porting to the cylinder.

Shortening the stroke means the crank will rotate through more crank angle degrees going from exhaust opening to transfer opening.

I´m not destroking this engine.
I was thinking to get more correct bore for the stroke i already have.
This engine is oversquare as oem.
Now i´ll decrease the bore to make it square.

[TZ350]

I got this question thou, is it possible that any YZ125 cylinder might fit on it?

If the cylinder does not bolt straight up and if you wanted to. It is possible to move the stud holes a bit.

We screw and glue a 20mm length of alloy into the old stud hole. Then use the cylinder as a guide and drill and tap new stud holes. Re drill one hole first and use it to hold the cylinder down while you spot the other holes. It can all be done with a hand drill. Nothing fancy required.

Kawasaki F8 350. Re-positioned cylinder studs to fit a Suzuki TS250 cylinder.

Suzuki GP100. Re-positioned cylinder studs to fit a Honda NSR cylinder.

The alloy plugs in the old stud holes can be seen next to the new cylinder studs.

[SwePatrick]

If the cylinder does not bolt straight up and if you wanted to. It is possible to move the stud holes a bit.

We screw and glue a 20mm length of alloy into the old stud hole. Then use the cylinder as a guide and drill and tap new stud holes. Re drill one hole first and use it to hold the cylinder down while you spot the other holes. It can all be done with a hand drill. Nothing fancy required.

Kawasaki F8 350. Re-positioned cylinder studs to fit a Suzuki TS250 cylinder.

Suzuki GP100. Re-positioned cylinder studs to fit a Honda NSR cylinder.

The alloy plugs in the old stud holes can be seen next to the new cylinder studs.

Yes,, i´ve done that procedure several times, but it would be very cool if they mounted directly, if not i might run for some more aggressive cylinders and not having to port them.
Like Roost 100cc or 2fast 100cc

[Haufen]

I´m not destroking this engine.
I was thinking to get more correct bore for the stroke i already have.
This engine is oversquare as oem.
Now i´ll decrease the bore to make it square.

I am not sure I understand. Are you above the displacement limit for your class at the moment and plan to aim for the maximum allowed displacement by decreasing the bore?
Or are you at the allowed maximum displacement now and would afterwards have an engine smaller than allowed but more square?

[katinas]

I am not sure I understand. Are you above the displacement limit for your class at the moment and plan to aim for the maximum allowed displacement by decreasing the bore?
Or are you at the allowed maximum displacement now and would afterwards have an engine smaller than allowed but more square?

The answer is in previous post about SwePatrick new project TZR 250cc 56/50 bore stroke engine.
"As my classrules says max 212cc i´m thinking about put thicker liners in them and run 50/50 bore/stroke and get ~196cc and a lot of material to bore if needed." until max 51.9mm bore for 212cc rules if liner wears out or damaged.