ESE's works engine tuner

[Frank S.]

The best process is using the EN36B and doing the correct rough machine, stress relieve , finish machine , then case harden with masking to 58-60 Rc.
But 4140 can be finish machined in one go then Nitrided on the pin bore and journals only , works just fine for cranks that will only ever get rebuilt a few times.

Yes, the machining in one go of the prehardened 4140 makes the part cheaper.
And nitriding is done at around 500°C, that makes less warping in contrast to 800°C+ at case hardening with carbon.
That is how we do most of our highly stressed parts

[ApolloMotoMoto]

Re the crank wheel press fits.
The best process is using the EN36B and doing the correct rough machine, stress relieve , finish machine , then case harden with masking to 58-60 Rc.
But 4140 can be finish machined in one go then Nitrided on the pin bore and journals only , works just fine for cranks that will only ever get rebuilt a few times.

Yes, the machining in one go of the prehardened 4140 makes the part cheaper.
And nitriding is done at around 500°C, that makes less warping in contrast to 800°C+ at case hardening with carbon.
That is how we do most of our highly stressed parts

Well now you are speaking my language...

We have two different development paths that are being worked "in parralel".

There is the race program development which is being used to "find" the failure points in the 'as prodcued' engine from the manufacturer. To understand these failure points and develop solutions that will allow us to push to the "next step" of power output and (ideally...) dominate on the track.

There is also the stock engine manufacturing development program that must take these solutions from the race program and find some way of applying them to the manufacturing evironement back in China as it currently exists. With the ultimate goal of "production engines" leaving the factory from China with the power level and crucially the "Power Range" to be the exciting/competative/reliable race engine packages for our racing series. Long, LONG term goal is to have "race level" engines (for our series) available directly out of China from multiple vendors, at a price point that allows us to fill the race-grid with bikes.

The "problem" we currently have, is that in order to have a competative race engine, you have to "know a guy"; or you have to be enough of a guru yourself to roll your own.

Beyond that, the parts required to sustain competative power levels in the top classes are not publicly available, and largely kept a secret when they are produced (not really suprising, eh?).

The stock engine manufacturing development program is making a lot of progress in this regard; we finally have a partner factory in China that is working directly with us as a team partner, supporting the races, and apply the changes we ask for as needed.


A 4140 (42CrMo is what it looks like they will actually be, as that is the closest 4140 equivalent that is locally available) material that can be final machined in one pass with no required stress relieving is exactly the process we need for the stock engines. As it stands right now, almost no-one ever services these cranks. The parts are so cheap, you just buy a new one. Racers are the only users who ever pop the cranks open, and that is only to install up-rated rods and bearings scavenged from scooter/motocross engines of similar displacement. Thankfully the stock rod development is actually much further along than the crank webs; double forged 20CrMnTi (equivalent to JIS SCM439) at HRC 35 through the beam, copper masked and carburized/case hardened to HRC 60 at the bores. With these new rods, we are anticipating we shouldn't have to immediately replace the stock rods in order to "go racing".


Thans all for the advice!

[SwePatrick]

Season is in it´s startingblocks.
One need to start making our engines ready for some racing.

I start here, i also set a goal, i´ll try to reach 90whp in my old TZR250 engine(1kt)
It is heavily modified ofcourse, running methanol.

Ported 3xv cylinders, blocked ypvs(there isnt any room to make them work, i tried)
Lectron 39mm(i bored out a couple of HV versions that had only 34mm venturis, now the venturi is 39mm, A-6 rods
V-force 4r with polini 0.4 petals.
Home made intakes
+5mm rods
Woessner yz125 pistons
Carbon clutch. with eight springs.
Pipes designed and built by me.

Earlier best result is 88.7whp at 11780rpm

So, does it perform aft sitting for about 4-5months?

Have a look:

[SwePatrick]

Dynoday2
Is it one of the hottest 1kt engines out there?

This years updates is only:
New reedpetals
New sparkplugs
Added electronic controlled powerjets(controlled by maxxecu)

I haven´t even opened the engine since last fall. *lol*
But compression is good, ~205psi.

Engine is running on Methanol.

Can i claim world record?
(At least worldrecord in a Yamaha 1kt engine)

https://youtu.be/9qPhcKbNhBU

[wobbly]

Sorry Patrick but you are nowhere near achieving any records at all.
With 90 RWHp @ 12,000 , that is, using your new, suddenly agreed to loss rate of 15% to the crank, equals 103.5 Crank power = 51.75 Hp/ cylinder.

But if we now conveniently take off 15% due to the increased performance from running Methanol ( easily achieved ) then you are back to 45 Hp Crank on Petrol.
This is a bmep of 13.44 bar @ 12,000.

The EngMod result of a 3YL TZ250 ( virtually a V configured 1KT ) using the same 3XV cylinders that bolt straight on, is 54 Crank Hp @12750 = 15.2Bar bmep.
Take off 15% gives 46 RWHp / cylinder on LL100 petrol.
The rpm increase is easily achievable as both engines have the identical short stroke- big bore configuration.
That is only 22M/s @ 12750 rpm.

So how you interpret your personal best result on Methanol, as being in any way world beating ( unless you consider where you live as " The World " ) like Mericans do, is beyond my limited intellect.

[Vannik]

I need to fill B-ports that were cast with too big a hook - it blows the mixture straight out of the exhaust port. Somebody posted here about an epoxy that they successfully used to fill the B-port passage by positioning the cylinder at a required angle and then poured the epoxy into the port. I tried searching for it but the search function does not agree with me. Does anyone have a recommendation?

[Frank S.]

I need to fill B-ports that were cast with too big a hook - it blows the mixture straight out of the exhaust port. Somebody posted here about an epoxy that they successfully used to fill the B-port passage by positioning the cylinder at a required angle and then poured the epoxy into the port. I tried searching for it but the search function does not agree with me. Does anyone have a recommendation?

https://www.kiwibiker.co.nz/forums/s...post1131229504

There it was, Devcon B

[TZ350]

.
My Suzuki RG50. Not world beating or even close but it gets me around the track.



Blue line is with the power jet tube connected and Red line is without the power jet on the 24mm OKO carburetor.

My Ignitech ignition can map and pulse a power jet solenoid.

Now to find a way to have a solenoid effect the switch over.

[lodgernz]

https://www.kiwibiker.co.nz/forums/s...post1131229504

There it was, Devcon B

A bit before then...
https://www.kiwibiker.co.nz/forums/s...post1131224551

[41juergen]

I need to fill B-ports that were cast with too big a hook - it blows the mixture straight out of the exhaust port. Somebody posted here about an epoxy that they successfully used to fill the B-port passage by positioning the cylinder at a required angle and then poured the epoxy into the port. I tried searching for it but the search function does not agree with me. Does anyone have a recommendation?

Hey Neels, that's what I use on my engines:

https://jbweld.co.za/

[wobbly]

The Devcon B Liquid Epoxy is actually manufactured in Australia. I searched around and found that it is about 1/2 the price there of the same product from other countries.
I also found that most retailers dont have it in stock , even though they advertise it for sale , they have to get it in.
Sadly I could never find out how to buy it from the actual source.

[F5 Dave]

Rob. All very noble endeavours. But I question to what extent you have optimised the main jet and the outlet position of the pv tube.

I made a bolt on tube with a solenoid from KX carb. Intention to ignitech off to extend the over rev. Didn't finish my experiment. Didn't get to eat my free lunch. Mal never did either.

[ken seeber]

The way I see it is that Devcon B is a steel based epoxy and Devcon F is an aluminium based epoxy. Surely, in an aluminium cylinder, the F would be the way to go as it would have a thermal expansion approx the same as the cylinder.

We have used the F on crankcases and cylinders.

https://www.blackwoods.com.au/adhesi...00g/p/04124908

Expensive, but you've gotta help Australia's ailing economy.

[TZ350]

I question to what extent you have optimised the main jet and the outlet position of the pv tube.

Stepped the main jet down from 125 to 100 in small increments and optimised the ignition curve a degree or two at a time until I had the Red line. The Blue line is the same settings as the Red line but with the Power Jet.

I think you are right, the power jet tube could be better placed but it is what comes standard with these 24mm OKO carbs. At a later date I am looking to change it, so it is lower and closer to the slide cutaway. I would like to start the power valve enrichining earlier. I think this will get rid of that dip. The dip was not there before with the larger 125 main jet.

I made a bolt on tube with a solenoid from KX carb. Intention to ignitech off to extend the over rev. Didn't finish my experiment. Didn't get to eat my free lunch. Mal never did either.

Its a bugger about missing the free lunch.

I am going to try an air solenoid that the Ignitec activates to bleed air into the power valve suction line. So as to collapse the vacuum sucking fuel in through the power jet.

Anyway, may get to see how that goes tonight.

[TZ350]

Blue line = PJ. Red line = No PJ. Green line Ignitec switches a solenoid to swap between PJ and No PJ. The solenoid admits air into the PJ suction line.


So the concept works. How about that....