ESE's works engine tuner

[Norman]

Thank you for the replies regarding the ATAC/powervalve. I see there is no really good point in taking any short cuts if one wants to combine an ATAC function with a powervalve blade. The right way is to regulate through a solenoid with a distinct controlled on/off point.

Referring to welding, I asked a professional welder to test the Hobart MAXAL 4943, she usually TIG weld with 4043 (ALSi5). She liked the 4943 better, and it looked good. One of the good things with this material is that it is possible to heat treat to T6, after welding. I have not yet tried to heat treat, and machine it though. We did this try out welding on my RGV cylinder.

[Tim Ey]

I see there is no really good point in taking any short cuts if one wants to combine an ATAC function with a powervalve blade. The right way is to regulate through a solenoid with a distinct controlled on/off point.

Or one may combine it with the fullest opening of a Yamaha YPVS as presumably was done at Proton

I can not imagine what the cigarette-box-alike attached to the YPVS will be otherwise.
Anyone got proof of my thoughts?

(I do not know how you guys deal with the copyright of pictures in this thread - This picture is from facebook. If it is not ok that i post it without a source let me know and I will delete it.)

[peewee]

Looks like KTM tried to do something more sophisticated like they told Neil Hints that they would. But eventually they found that the Kiwis already had a handle on it and KTM copied what was tried and true and already working properly in New Zealand.

long time ago I said there might be spies. figured someone would of snatched wobblys oval port cheetah idea and took it to market for themselves but I haven't seen any turn up.... yet . just a matter of time I suppose

[seattle smitty]

Referring to welding, I asked a professional welder to test the Hobart MAXAL 4943, she usually TIG weld with 4043 (ALSi5). She liked the 4943 better, and it looked good. One of the good things with this material is that it is possible to heat treat to T6, after welding. I have not yet tried to heat treat, and machine it though. We did this try out welding on my RGV cylinder.

Last I checked, the big local welding supplier here was holding off of carrying the 4943 wire (which I was trying to buy), having had some negative feedback from the shipyards. If I can find out anything worthwhile, I'll pass it on.

[peewee]

FWIW, Jeff Henise and I spent the afternoon machining two TZ350 heads to convert them to replaceable combustion chamber inserts for his Bonneville LSR project.

I did a simple program at the mill and machined the first head and everything went along fine -- not as fast as possible (no flood coolant on my mill) but no excitement either.

The second head was a different story. It either at some point got hot enough in use to completely anneal it or that batch of heads was from a different alloy or HT spec from the first. Nasty gummy aluminum, building up on the cutter to the point of making the head extremely hot from rubbing as well as pushing it out of position (4 clamps, the first head had no problem) 2/3 of the way through the cycle.

It would be interesting to know what was going on. The same end mill that worked a treat on the first one immediately went into "I'm not happy" mode on the second one so we're pretty sure it was the head casting and not anything we were doing (same program as the first head). Slowing the feeds and RPM down by about 2/3 took some of the "why is the coolant smoking so much?" heat out of the head but even with that the EM was clearly pushing metal around instead of cutting it.

I guess it is just part of the mystique of old race bikes.

cheers,
Michael

just a shot in the dark here but when I do any heavy cutting with my carbides I run it in candle wax every so often and chews through alum like butter all day. without the wax it smears up the bit in minutes and its a bugger to clean out the teeth. if you cant run a continuos flow of cooling oil then maybe try drastically reduce the feed and bit speed

[peewee]

Looks like an atac valve.
They are just a chamber about the same size as the engines cylinder, and a butterfly valve.
They do work on increasing low end power as long as they are mounted close to the exhaust port.
They have been used in various incariations on Honda CR NS and MVX as well as the BSL500 and Cagivas.


Suzuki and Kawasaki have also used more compicated variations of exhaust chambers.

the this is how they work
note the butterfly is mounted 90' away from how it is pictured here

This was Farmakens DIY effort (maybe not its a twin lol)

I bet you forgot all about ktm's version

[jasonu]

just a shot in the dark here but when I do any heavy cutting with my carbides I run it in candle wax every so often and chews through alum like butter all day. without the wax it smears up the bit in minutes and its a bugger to clean out the teeth. if you cant run a continuos flow of cooling oil then maybe try drastically reduce the feed and bit speed

Stick fat like lard works great to keep cutters and abrasives clear but attracts pigeons and other wild life if you don't clean it up.

[2T Institute]

I think I might have seen those before

How did they go in the end?

Never actually tested I have them at home now. The XR89 Suzuki RGV 500 uses a triple stage PV AND a AEC chamber. The AEC closes first then the PV opens. That was needed to pump up the bottom end to make the power linear.

[Michael Moore]

try drastically reduce the feed and bit speed

I did cut feed/RPM down midway through the second head which did help to reduce the heat in the part, but the metal was still very gummy. The original settings worked fine on the first head.

I've seen old machinists swear by the magic lubricating powers of bacon fat. It has to smell better than regular cutting fluid!

[husaberg]

Never actually tested I have them at home now. The XR89 Suzuki RGV 500 uses a triple stage PV AND a AEC chamber. The AEC closes first then the PV opens. That was needed to pump up the bottom end to make the power linear.

Cagiva combined a Atac with a PV as well, most of the need to do this i assume disappeared with the introduction of unleaded fuels.

[jonny quest]

Why would it disappear with the use of unleaded fuels?

[wobbly]

Most MX manufacturers have had a go at ATAC within the cylinder, or out the side or top.
Usually as the PV blade moves, it closes of a port to the chamber volume.
Fuel quality has no effect on the powerband width.

[guyhockley]

Thank you for the replies regarding the ATAC/powervalve. I see there is no really good point in taking any short cuts if one wants to combine an ATAC function with a powervalve blade. The right way is to regulate through a solenoid with a distinct controlled on/off point.

Not a very good picture, I'm afraid...

[Flettner]

long time ago I said there might be spies. figured someone would of snatched wobblys oval port cheetah idea and took it to market for themselves but I haven't seen any turn up.... yet . just a matter of time I suppose

I guess so, the only plus is being able to say it was seen here on Kiwi Biker first. No, it was TSM first, whatever. I work by myself now, can you tell.
I have to admit this KTM's, YZ injection copy has got me fired up to finish the 360 reverse cylinder engine with the NEW injection layout. Link bless them are looking into supplying an ECU for this project, finally they can see I wan't full of shit after all, well not completely anyway.

[TZ350]

.

Injector Position



Central injector fires through a slot into the underside of the piston.

My favourite low speed injector position has been to fire under the piston. This seems to help enormously with fuel homogenization at lower and off pipe engine speeds.



My least favorite and less successful position has been to inject directly across the crankcase into the oncoming inlet air stream. During periods of air flow reversion fuel gets blown out the inlet. And also at higher speed low throttle there is not enough time for a small squirt of fuel to travel right across the crankcase for even fuel distribution.



Looking at a piston positioned slightly below transfer port opening the two clean spots at the edges look to me like marks left from air/fuel short circuiting from the A ports and washing the carbon away.

When I showed this to Flettner and asked about injector positioning. He suggested an injector in each of the A and B ports.



Flettner suggested the B port injectors should handle the low speed fuel demand leaving only fresh air short circuiting from the A ports.

And any short circuiting is most likely at lower engine speeds before the reverse pressure wave action from the pipe blocks the exhaust port as the motor gets up into the power band.

At higher engine speeds when the motor is up on the pipe, then have the A port injectors chime in. That way with fuel injected into all four A and B ports the mixture should be pretty homogeneous. Flettner's idea sounds better than what I have been doing which is trying to combine two purely air streams from the A ports with two overly rich streams from the B ports and have them properly mix together in the cylinder.

As for problems coming back on the throttle after shutting off for a corner Nath88 suggested that at less than 20% throttle the EFI ECU needs to be able to differentiate between when the engine is firing and the pipe is sucking and creating a higher bulk air transfer through the motor and therefor fuel demand verses when the wave action in the pipe has totally collapsed and much less fuel is required.

The Alpha-N map can’t do this by itself, there needs to be some way for the ECU to tell if the engine is firing and the pipe sucking or not. Nath88 suggested measuring the return positive pressure pulse at the exhaust port. It is a great idea and I like it but unfortunately, I have not found a way to get my Ecotrons EFI software to do that.

Flettner suggested measuring the internal pipe pressure at the dwell section in the middle of the pipe. He pointed out that the pressure must drop when the wave action collapses and that by using a VE table below 20% throttle/load and Alpha-N above that I might be able to train the ECU to recognize when the motor is firing and wave action in the pipe is increasing demand for fuel.

I like Flettners idea of low speed injectors in the B ports and secondary injectors in the A ports that chime in when the fuel demand under full power/load requires all four injectors.



I have ordered more parts from Ecotrons and my next challenge is a lack of room and to figure out how to fit a secondary injector close to the power valve actuator.

When I followed Nath88's very clever idea about using the return pressure wave at the exhaust port to see when the motor was firing. I ran into a problem, my ECU software averaged the low suction pulse and high plugging pulse and arrived at a lower average for on power open throttle compared to closed throttle. Makes sense when you think about it but I could not figure out how to get the ECU to make sense of it. Basically it needed to reduce fuel when the average pressure was higher and increase fuel when it was lower. This is opposite to the way EFI ECU's think.

In the mean time I am going to get this Beast going again and try Flettners idea and see what sort of average pressures are in the dwell mid section of the pipe and if the EFI ECU can make sense of them.