ESE's works engine tuner

[husaberg]

Very late reply!Husa asked in Nov 15,2011(page 360) if anyone tested the ignition curve from a KTM 50SX iggy,well I did today,,planning to use it on a one off Minarelli scooter engine,so I built a test rig.Sorry to say its a "flat liner",no curve at all!Back to the drawing board...

Chairs, the latest ones i see are are digital now though, so they will have a curve i hope.
They are still a neat little set up, and cheap as chips.

Price:$299.00 + $4.49 shipping
https://www.amazon.com/DIGITAL-IGNIT.../dp/B00CFL5QLU

http://www.ktm-parts.com/mm5/graphic...XS12050039.pdf

For an idea just how big they are for those unfamilar with the little KTM's

[wobbly]

As you have gone 1/2 way and put in the bore/duct radius you may as well go all the way and epoxy fill the B port front wall
as Jan did as a successful test on the Aprilia.

[41juergen]

Thank you guys for the feedback.
Currently I have 3,0 mm distance from the main to the aux ex port, can I go narrower, let's say to 2,0 mm (I remember the 5KE TZ cylinders had a problem there with cracking walls)?
Ok Wob as you say, now I'm already not too far from a good setup I will do that too. The front of the B port has already the right direction at the outlet to the cylinder, but to minimize the lost of energy I will correct also the complete wall.
BTW: when cutting so much on a cylinder is a re-plate a must? As that is my first attempt my idea was to test that setup let's say for about 2-3000 km on the road and then put in all the new stuff (like piston, crank, etc.).

[ken seeber]

I muse maybe for a twin sided disc valve to make a lot more power than a single it would require an intake track with a very large updraft that way some of the airflow would go directly up the transfers on the same side rather than colliding and thus losing velocity in the middle an into the conrod?
I note the kreidler 50 with 2 discs had the intakes facing steeply towards the crankwheels rather than being straight a well. packaging?

Was thinking about this and wondered that, instead of having the two disc valve passages being coaxial or on a plane, have them enter the under cylinder volume semi tangentially.
One could enter under the A passage entry point on one side and the other, on the opposite side, enter under the B passage. This would eliminate any direct collision of the streams, but dunno about the connecting rod impeding the flow over the cycle.
Also, the possible resultant swirl motion above the crank might create some asymmetry to the flow entry into the transfer passages.

[jamathi]

Was thinking about this and wondered that, instead of having the two disc valve passages being coaxial or on a plane, have them enter the under cylinder volume semi tangentially.
One could enter under the A passage entry point on one side and the other, on the opposite side, enter under the B passage. This would eliminate any direct collision of the streams, but dunno about the connecting rod impeding the flow over the cycle.
Also, the possible resultant swirl motion above the crank might create some asymmetry to the flow entry into the transfer passages.

A very good idea, I was thinking about that too..

[wobbly]

The problem with grinding a cylinder is that the main exhaust will then not have the plating going around the corner from the bore into the port.
As the ring bulges outward,and the top/bottom port radi with a chamfer help to guide it back into the groove,eventually the plating will be worn thru to alloy - or chipped away.
You can smooth the edge with a cotton mop to help the situation,but for sure it will last long enough to test the porting results.
The transfers dont give any problems, as they dont need a chamfer at all.

[shnaggs]

was having some fun with my computer these past few days. Still trying to figure out the Ryger and how this design software works

Trying to figure out how to animate the damn thing!

[Michael Moore]

Very late reply!Husa asked in Nov 15,2011(page 360) if anyone tested the ignition curve from a KTM 50SX iggy,well I did today,,planning to use it on a one off Minarelli scooter engine,so I built a test rig.Sorry to say its a "flat liner",no curve at all!Back to the drawing board...

Could you post a photo on your test rig? I need to run a 2015 KTM 250SX ignition as I can't find anyone who has any idea of what the map in it looks like and I don't know if it will be suitable for RR use instead of MX.

thanks,
Michael

[peewee]

was able to finally start it today so thnx to everyone on this site who offered assistance along the way . wasn't tuned real well since I had to steal the carb from my Honda but never the less it runs and there were no immediate mechanical failures. ill put the methanol carb back on and run it again after the mud dries up in a few weeks. probly do alittle more work to the head like install a mechanical compression relief so the crankcase doesn't break at the kickstart area and may lower the com ratio a bit

[190mech]

Here is my backyard(bucket) method,machined a shaft(read bolt) to match the crank profile,install it into cases,add iggy,TrailTech tach,spark plug and timing light,degree wheel or protractor on stator to read curve at different RPMs(not used in my case)Spin it with a DoAll dental drill motor attached to the shaft

Wobbly has a vid of his rig somewhere in this thread that uses a vacuum cleaner motor,waay more hi-tech than my rig!

https://www.youtube.com/watch?v=pA6k...w&feature=plcp

[d2t]

The transfers dont give any problems, as they dont need a chamfer at all.

Even if it's not needed to guide the rings back into place, isn't there still some benefit to airflow? I had always thought sharp edges were the enemy of good aerodynamics.

[jfn2]

was able to finally start it today so thnx to everyone on this site who offered assistance along the way . wasn't tuned real well since I had to steal the carb from my Honda but never the less it runs and there were no immediate mechanical failures. ill put the methanol carb back on and run it again after the mud dries up in a few weeks. probly do alittle more work to the head like install a mechanical compression relief so the crankcase doesn't break at the kickstart area and may lower the com ratio a bit

You gotta love those paddle tires! Sounds pretty good.

[Michael Moore]

Here is my backyard(bucket)

thanks, that's pretty much what I had in mind though making a dedicated housing rather than using the crankcase.

cheers,
Michael

[41juergen]

Even if it's not needed to guide the rings back into place, isn't there still some benefit to airflow? I had always thought sharp edges were the enemy of good aerodynamics.

But you want the flow in the desired direction, that would be (a least a little) influenced by the grinding....
One other point came back into my mind: Wob I think you mentioned some when before that the aux ex ports shall be some °CA lower as the main ex port, otherwise one would loose some significant power in the lower power band. Is that valid also for aux ex ports which are connected to the PV (as the Yamaha drum type is)? If not I can get some more blow down there...

[wobbly]

Transfer ducts with whats called "exit " flow benefit far more from the sharp edges at the bore as the gas that forms the scavenging regime
maintains a much better coherent stream.
With bore chamfers the column edges break up, and eddies or tiny turbulent swirls are formed that compromise the directional contol.
Jan tested this at Aprilia, and i have done a direct back to back on a KZ10B, dynoing at 47.8 Hp with no chamfers, then immediately loosing
near on 1 Hp everywhere after chamfering all the transfer ports - creating a ruined cylinder in about 10 minutes .