ESE's works engine tuner

[TZ350]

I take it you mean 32 degrees at the start of the ignition curve with it retarding with higher revs other wise the cooling ability of methanol is amazing.

Back in the day I had a Suzuki twin on Methanol and straight line ignition. One day I advanced the ignition a crazy amount, I mean real crazy amount and the engine pulled like a big four stroke until it started coming onto the pipe. Then it pinked like crazy. No ignition curves back then. I never forgot the possibilities of that experiment. Now that you can get ignitions with variable curves I am going to re-visit that experiment.

I was expecting the EngMod-2T suggested 32 until it started getting on the pipe. Then steeply retarding to 18 which is the std timing. EngMod suggested 32 everywhere.

Working in 2 deg steps I am well over 18 in the power band now. By test on the dyno the Kawasaki seems to like heaps of advance everywhere.

Methanol is strongly resistant to detonation especial if it has a dash of water in it, but it's a bit vulnerable to pre-ignition. Acetone at 10% helps with suppressing that pre-ignition tendency and running rich helps here too.

I still have lots of work to do to get the fueling right and finalizing the ignition curve. I will post the fuel, carb spec and ignition curve when I am finished.

[husaberg]

Back in the day I had a Suzuki twin on Methanol and straight line ignition. One day I advanced the ignition a crazy amount, I mean real crazy amount and the engine pulled like a big four stroke until it started coming onto the pipe. Then it pinked like crazy. No ignition curves back then. I never forgot the possibilities of that experiment. Now that you can get ignitions with variable curves I am going to re-visit that experiment.

I was expecting the EngMod-2T suggested 32 until it started getting on the pipe. Then steeply retarding to 18 which is the std timing. EngMod suggested 32 everywhere.

Working in 2 deg steps I am well over 18 in the power band now. By test on the dyno the Kawasaki seems to like heaps of advance everywhere.

Methanol is strongly resistant to detonation especial if it has a dash of water in it, but it's a bit vulnerable to pre-ignition. Acetone at 10% helps with suppressing that pre-ignition tendency and running rich helps here too.

I still have lots of work to do to get the fueling right and finalizing the ignition curve. I will post the fuel, carb spec and ignition curve when I am finished.

i would think the addition of the acetone should helps keep the oil in suspension plus decreases the need for huge amounts of advance.as well as making it easier to start.
Grump wanted me to post this video on go kart engine balance factors.

[wobbly]

Way back when we could run Methanol in Open karts I did a bunch of testing on what was the best setup.
This was water cooled mind - but it ended up that the optimal ignition on petrol was exactly the same on Methanol , but instead of 15.5 com ( on Avgas ) it went to 18.5 and the fastest fuel mix was with 10% Acetone and 10% Avgas.
Straight Methanol , or any more petrol was alot slower , and needed drastic jet changes to keep it alive.
Very similar scenario on another project just finished was a TD2 Yamaha Aircooled , that had an Ignitech with a curve I would consider dead normal petrol suitable ie 28* under the pipe dropping to 15* at peak power
then another 5 drop to the rev limiter.
That happily ran 16:1 com with the same 10% AvGas/Acetone mix.

[Vannik]

I was expecting the EngMod-2T suggested 32 until it started getting on the pipe. Then steeply retarding to 18 which is the std timing. EngMod suggested 32 everywhere.

Please see in the Engine Dialog Box where you specified peak engine power will be - EngMod2T should not predict a straight line.

[TZ350]

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I will have a look and see what I have done. No surprise if I have messed it up.

[Frits Overmars]

A question for Frits:
I seem to remember that you had a major hand in writing the rules for the Freetech 50 class.
I wondered why you effectively eliminated cast iron cylinders or cylinders with a steel liner, by allowing no overbores past 50cc.
Even the first oversize on a Honda NSR50 (39.25) puts it over 50cc. Was that deliberate?

It is true that I was solely responsible for drafting the original regulations, which were accepted by the Freetech50 board without amendment.
Nowhere in the regulations is there a prohibition against enlarging the bore. You may enlarge it as much as you want, as long as you ensure that the maximum allowed engine capacity of 50cc is not exceeded.

In the past I have drawn up regulations for other competition organizations at home and abroad, always striving to make the rulebook as simple as possible and to create equal opportunities for everyone, regardless of the size of their wallet, and I had noticed that allowing an exceedance of the prescribed cylinder capacity was abused by some wealthy participants to have their nikasil-plated cylinder bores enlarged to the maximum, which only exacerbated the disparity against their less fortunate opponents.

Anyway, the technical level in Freetech50 has currently reached a level where a cast iron cylinder or a sleeved cylinder is thermally overloaded to such an extent that you do not stand a chance, whether that cylinder may be overbored or not.

[diesel pig]

Very interesting posts about the methanol ignition curves, I wonder if engine mods cals is saying in a round about way that on methanol the Kawasaki has way to low compression ratio and one could get away with 32 degrees all the way though ?

[TZ350]

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No, I may have cocked up and put in incorrect numbers while exploring possibilities. Easy to make changes with EngMod to see what the affect is. I don't always keep good notes on the effects of my changes.

I have re checked the base timing of the Ignitec, it was Ok. So the ignition map timing generally reflects the actual timing.

I have some idea of where I am headed and now I have to do the work and see what the dyno has to say.

[wobbly]

The huge advantage of running Meth in an aircooled engine is that effectively the high latent heat is so good at cooling it makes the cylinders performance able to be equivalently tuned
to that of a watercooled.
There is no barrier to making too much power , that usually overcomes the cylinders ability to reject heat , and thus you get high thermally limited drop off even with very mild tuning.
Adding large amounts of petrol simply degrades this huge technical advantage for no logical reason imho.

[F5 Dave]

And presumably you are running a higher than usual comm Rob?

[TZ350]

And presumably you are running a higher than usual comm Rob?

250cc single at 18:1 swept.

Something I found on the net by Bell about plugs:- https://www.strappe.com/plugs.html

[wobbly]

18:1 in an aircooled 250 is only going to work reliably if you have a very modest bmep tune , and are using the com to generate a fairly large part of the power increase.

[TZ350]

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Getting better. Red line is where we are now.

[TZ350]

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Those cylinder base nuts have started loosening again.

It has become obvious that before I can ride this thing I will have to tear the engine down and change the balance factor.

I am also suspicious about the initial ignition timing setup. I am having to wind in way more timing than expected. Maybe the base advance is wrong or the Ignitec's "Auto" trigger point shifts???

Others with more experience than me suggest that with methanol advanced down low and tapering back to normal petrol timing at peak torque is the expected way to go for methanol.

Also the com ratio is probably best closer to standard as the dynamic compression ratio with the cooling effect of methanol is much greater than with petrol. So I don't need to go to my current high 18:1 com lengths that you generally see in methanol four strokes.

We will see where we get too with a bit more dyno work then I will tear the engine down for a re balance and a com check/adjustment.

Ignitec set for Auto polarity trigger pickup.

TDC position of ignition rotor. Rotor marked at 15 deg before TDC relative to the center line of the trigger. Anti clockwise engine rotation.

Rotor photo'd at 15deg BTDC. This is what I expect to see with a timing light and a 15deg ignition straight line at any rpm.

Base advance.

Base advance adjusted by having a 15deg straight line ignition map and adjusting the base advance until I could see the 15deg BTDC rotor mark align with the center of the trigger using a timing light at 2,000 rpm.

By coincidence the actual base advance turned out to be 15 deg, It could have been anything from 30 to 0 to get the 15deg BTDC mark on the rotor in the right place.

After this setup any point on a real ignition map should be reflected in an actual real life ignition event relative to crankshaft position. I.e. if the map says 28 deg a spark will occur 28 deg BTDC.

One lobe, one pickup (only one Ignetec pickup input used). Ignetec DCCP2 Race with both channels going to the one coil.

Any advice here would be welcome.

[wobbly]

The only time I have ever seen base and or head nuts winding out is due to detonation - even if its not enough to create piston issues , constant background deto puts huge shock forces on the fixing studs/nuts.
Ive seen this in a big bore 1150 Seadoo that had the wrong fuel poured into it , and one of the early tests I did on a TM125MX kart where I tried 20:1 com on Methanol - it did 4 laps and the cylinder simply " fell off ".
The other one was a 250 KTM on Methanol where some idiot in a wheelchair measured the com at 16cc to the top of the plug , instead of 16cc + 2.2 of thread , it rattled like mad in the mid , and all the nuts unwound.
I would suspect that at 18:1 in an aircooled 250 the com is simply way too much.
My take would be 15:1 com would give a good combination of cylinder cooling Vs power production from the Methanol.


EDIT - and of course you know the easy way to check base timing is to set the piston at TDC and use a marker on the stator/rotor to put reference lines.
Set the timing in the Ignitech to zero , and spin it over on the dyno with the plug sitting on the head , and strobe the marks.
From memory it fires on the base timing up to 300 rpm , over that the programmed values.
If the lines dont line up past 300 rpm, then the base timing is wrong.