ESE's works engine tuner

[Lbracing]

Thank you Wobbly for the input ! Much appreciated !

Has anyone heard or even better tested WPC ? Is the so called ''magic'' around it working ? I am mostly interested in it for piston skirts .

[RomeuPT]

Good info about countershaft's!

Does anybody know if a stator/alternator from the road 2stroke bikes causes some drag to the engine if there is no load/demand for power?

cheers

[TZ350]

Good info about countershaft's!

Does anybody know if a stator/alternator from the road 2stroke bikes causes some drag to the engine if there is no load/demand for power?

cheers

If it absorbs energy from the motor it would heat up like a brake does, energy absorbed has to go some where.

[peewee]

Hello everyone ,

My name is Luc from LBracing , I have read the whole thread twice over the last two years and I must say the amount of information is mindblowing . I would also like to thank EVERYONE who contributed to making this happen .

We are based in Canada and build chaisaw engines for speed cutting ranging from 50cc to 140cc and have been for close to ten years now . We manufacture our own pistons , heads , cylinders and carburetors all from billet .

The only limitations are :
cc class
Production based ( mostly look like a production chainsaw except from the pipe )

Wich means we can run any fuel ( usually methanol with 20 up to 30% nitro ) .

We always run the stock ignition coil ( sem AM50 , AM33 (flat line ignition)) but I have been looking to upgrade to something more powerful and reliable . I have been looking at universal PVL and selettra ignitions but I am totally lost as I don't know anything about them . Maybe some of you guys can help me ? ( wobbly , kart ignition ? )

Here are factors to consider :
-Acceleration speed is important for categories where we must start the chainsaw from the ground and then do the usual 3 cuts .
-Low and mid power is unimportant , only peak power is .
-Peak power is ranging from 14000 to 16000 depending on the engine size .
-Ignition must have a low rpm cut in point ( 500 rpm )
-We run R7376 plug in all our engines .
-Compression ratio is usually around 19:1 .
-It usually takes under 3 second to complete the cutting so heating the engine is very unlikely to happen .
-Ignition advance is currently 25-27* .

Thank you for your time !

good to see you here luc. the more 2t experts there is here the better. do the rules only allow 30% nitro or mechanically thats all your engine will tolerate or theres some other reason ? ive just started using nitro in my engine and could use all the help i can get.

what i found out rather quickly is the low throttle position needs richened quit alot , even with small nitro pecentages. i richened the lectron needle as far as it could go , 2.5 turns more than i had been using with straight methanol and it still wasnt barely enough as it had a small run away at idle but ive got a richer needle that will be here in a few days so i hope it can provide enough fuel for about a 20% mix.

recently ive been using only #10 heat range plug and it seems to be doing fine, so ill probly just continue with those unless theres a good reason to use something else

one question i have is about the afr range that nitro is happy with. with methanol it seems to do fine and make good power even when pig rich. leaning it out made no difference in power that i could tell and just caused the water temp to rise rather quickly. does the nitro methanol mix also work fine when excessively rich or it responds better if its leaned a bit ? unfortunatly i dont have a dyno or any other fancy machines so i can only test by seat of the pants and listen for any strange engine noises

my comp ratio is 16:1 (527cc single cyl engine) because originally i planned on only using straight methanol. but in my research about nitro it seems lowering the comp ratio as the percentage increases is the way to go. except in special situations like your largely over sqaure engine i suppose. so im not sure if the 16:1 will some day cause me any trouble or not.

[Lbracing]

good to see you here luc. the more 2t experts there is here the better. do the rules only allow 30% nitro or mechanically thats all your engine will tolerate or theres some other reason ? ive just started using nitro in my engine and could use all the help i can get.

what i found out rather quickly is the low throttle position needs richened quit alot , even with small nitro pecentages. i richened the lectron needle as far as it could go , 2.5 turns more than i had been using with straight methanol and it still wasnt barely enough as it had a small run away at idle but ive got a richer needle that will be here in a few days so i hope it can provide enough fuel for about a 20% mix.

recently ive been using only #10 heat range plug and it seems to be doing fine, so ill probly just continue with those unless theres a good reason to use something else

one question i have is about the afr range that nitro is happy with. with methanol it seems to do fine and make good power even when pig rich. leaning it out made no difference in power that i could tell and just caused the water temp to rise rather quickly. does the nitro methanol mix also work fine when excessively rich or it responds better if its leaned a bit ? unfortunatly i dont have a dyno or any other fancy machines so i can only test by seat of the pants and listen for any strange engine noises

my comp ratio is 16:1 (527cc single cyl engine) because originally i planned on only using straight methanol. but in my research about nitro it seems lowering the comp ratio as the percentage increases is the way to go. except in special situations like your largely over sqaure engine i suppose. so im not sure if the 16:1 will some day cause me any trouble or not.

There is no rule regarding fuel , more than 30% just doesn't add anything from our testing . We see an increase , mostly in rpm , going from 20 to 30% nitro thought .

We run R7376-10 plug in everything and its been working great !

Nitro carrying a healthy dose of oxygen , makes the mix as much if not more rich tolerant . Setting the engine very rich also take care of a lot of temperature and atmospheric pressure fluctuation .

Regarding compression ratio , your application being far from my scope of expertise , I wont advise anything . The idea behind reducing the comp ratio is mostly because of the low octane rating of nitro . As stated earlier in this thread , at high rpm the octane needed lowers trendemously wich is probably another reason why we can get away with such high nitro percentage and comp .

[koenich]

+1 here,
also,I think YZ 125 & 250 are running without a balance shaft,am I right?
Does anyone know balance factor's used there?
Cheers

jep no balance shaft, the new KTM 250SX is the only 2-stroke engine which has one. I don't know the balance factors but from my understanding the "soft" tires and whole chassis sort of distribute the vibrations differently and they don't end up on the handlebar/pegs/seat that much. The MX engines which are used for road racing usually vibrate like sh*t where as in the MX chassis it's totally different...

[speedpro]

MB100s have balance shafts, just sayin'.

MX engines in road race applications are revved harder for longer I suppose and I expect nobody bothers to rebalance them for the application. Pretty stupid considering how easy it is in a single. No maths required, you know which way to go, make a change and test.

[peewee]

There is no rule regarding fuel , more than 30% just doesn't add anything from our testing . We see an increase , mostly in rpm , going from 20 to 30% nitro thought .

We run R7376-10 plug in everything and its been working great !

Nitro carrying a healthy dose of oxygen , makes the mix as much if not more rich tolerant . Setting the engine very rich also take care of a lot of temperature and atmospheric pressure fluctuation .

Regarding compression ratio , your application being far from my scope of expertise , I wont advise anything . The idea behind reducing the comp ratio is mostly because of the low octane rating of nitro . As stated earlier in this thread , at high rpm the octane needed lowers trendemously wich is probably another reason why we can get away with such high nitro percentage and comp .

thanks for the insight. i would be interested in seeing how your carb and fuel system is setup when your able to post photo

whats your thoughts on oil content ? i started using 16% (75% caster 25% synthetic) mostly because i read it should help slow internal wear. since im not racing professionaly i would rather have the piston and bearings last a bit longer

[SwePatrick]

If it absorbs energy from the motor it would heat up like a break does, energy absorbed has to go some where.

No
It can´t absorb more energy than it´s own weight can produce.
It never absorbs energy from the engine, just from it self.
And as there are no friction the heatlosses are very very very very very small, (if there even are any?)
As a rotating weight has the only friction coming from surrounding air or fluid, you have to go faster than a spaceshuttle coming through the atmosphere to build some melting heat
Why faster?
Because it has so small frictionarea compared to the spaceshuttle

[RomeuPT]

If it absorbs energy from the motor it would heat up like a break does, energy absorbed has to go some where.

you are right, should I test the bike running the cdi only with the battery to see if the stator cover gets hot? Or I can be asured alternators don't do any drag without power demand?

[RomeuPT]

jep no balance shaft, the new KTM 250SX is the only 2-stroke engine which has one. I don't know the balance factors but from my understanding the "soft" tires and whole chassis sort of distribute the vibrations differently and they don't end up on the handlebar/pegs/seat that much. The MX engines which are used for road racing usually vibrate like sh*t where as in the MX chassis it's totally different...

I have the SX from 2002, and vibration is insane, is probably the biggest issue of the bike. Can barely take a sit and relax . But still great bike.

[Lbracing]

thanks for the insight. i would be interested in seeing how your carb and fuel system is setup when your able to post photo

whats your thoughts on oil content ? i started using 16% (75% caster 25% synthetic) mostly because i read it should help slow internal wear. since im not racing professionaly i would rather have the piston and bearings last a bit longer

We run pumper carbs because of all the angles we put the saws at and for spacing reasons . I doubt seeing them will be of any help to tune your lectron / float type carburetor .

When running methanol , especially with some nitro mixed in , a LOT more fuel goes thru the engine already improving lubrification trendemously so 16% is excessive for anything but model engines . We run Klotz Original Techniplate mixed with a ratio of 6% .

[RomeuPT]

No
It can´t absorb more energy than it´s own weight can produce.
It never absorbs energy from the engine, just from it self.
And as there are no friction the heatlosses are very very very very very small, (if there even are any?)
As a rotating weight has the only friction coming from surrounding air or fluid, you have to go faster than a spaceshuttle coming through the atmosphere to build some melting heat
Why faster?
Because it has so small frictionarea compared to the spaceshuttle

Thanks!
Then I should replace all lamp's to led lights all over the bike and use a battery smaller has needed so there is minimal drag/load on the alternator!?

[nitro2tfx]

There is no rule regarding fuel , more than 30% just doesn't add anything from our testing . We see an increase , mostly in rpm , going from 20 to 30% nitro thought .

Something is very much not right if you are not getting more power with higher nitro %. Going to higher nitro % does NOT generate diminishing returns it generates greatly increasing returns.

It is best to think of nitro like this : instead of thinking you have methanol with an additive (30% nitro), think of it as you have nitro with a massive % of low powered diluent, that being methanol, (you have nitro tamed with 70 % methanol).

On a 4 stroke NA engine you can expect about 5-6 times as much power on 100% nitro as on 100% methanol under the right conditions. You could do even better than that on a 2 stroke if you ignored the fact that the cylinder pressure had to blow down before the transfers opened LOL, but of course that is something that can't be ignored. As you reduce the diluent (methanol), blowdown becomes an issue, when blowdown becomes an issue so does power, and when blowdown becomes a big issue "crankcase venting" may occur. I think you can see where I'm going with this.

[Frits Overmars]

On a 4 stroke NA engine you can expect about 5-6 times as much power on 100% nitro as on 100% methanol.

Maxim in the office of a dragracing friend: