100shp bike

[dieselguy86]

Hi gents,

Micro valve driver is now in. It is small and very cool, capable of 2 inputs/ outputs, either together, seperate, or a mix of either. You input a 0-5v signal and it converts it to a pwm signal. Pwm frequency range from 30hz to 500hz (the direct acting pressure relieving valve I ordered has an optimal pwm of 200hz)

Next it has a min setting, this will be my start/ idle setting. Because I'm using direct injection with no preheat, I need the fuel to immediately come in at a certain psi. 
Obviously if there's a min setting, there's also a max setting, aka 100% rpm.

The part I like the most is it has a programmable ramp time, this is how fast it reacts to throttle changes. So I can move the throttle as fast as I want without worrying about causing a flameout.

Programming is done via jumpers and pot in the back of it, there is a gate module that connects to it and uses a wifi signal to allow remote programming via there software. I didn't buy it as it was an extra $200, but I'll probably get it as it's going to be a pain having to move jumpers and guess where to move the pot when adjusting things like pwm min/ max and ramp time. 



Red: +vdc 
Black: -vdc
Orange: +5vdc reference to throttle potentiometer 
Blue: output of pot into the #1 input
Yellow: pwm output to the pressure relief valve

Doesn't get much simpler than that, now I hope it works good. I hate temperamental electronics that don't have repeatable accuracy. 

[ausjet]

I use an adjustable check valve set to 60 psi inline on the fuel side, fitted just before the injector. It allows the injector to snap open and closed way quicker than what’s possible with just turning the pump on/off with the pwm controller.

[dieselguy86]

Pump will be running constant. I'm basically using the same as you, just electronically adjustable.

[dieselguy86]

Hi all, 

Printed my diffuser as it is to date, holding it in my hands gives me a better feel for how it really looks vs on a computer screen. 





Trying to stuff it into a 5" fire extinguisher case, I tried to roughly scale up Gerald Ruttens designs size-wise. His combustor is only ~2.5x's inducer area. I will be right around that, but I think in order to fit all my injectors I'm probably going to have to go up to a 5.5" case. 

[racket]

Hi Joe

Yep , you might be a tad tight at 5" , another half inch will give you 20% more area to play with .

Having a "hard copy" makes it much easier to appreciate whats required , gives us the chance to see if it "looks right" .

Cheers
John

[dieselguy86]

Hi John,

Yea I think going to a 140mm/5.5" case makes sense, not like I don't have the space for it.

I've been thinking on injector placement. I would like to have it spray radially outward just behind the front wall, this will give me the longest combustor.

Other thought was spraying them axially, and making up some "reverse" bell mouth inserts to weld into the front wall to try and "diffuse" and slow the spray down and get it mixed in good. I'm using aeromist nozzles with .012" holes, so should be atomized really good.

[dieselguy86]

Hey all, 

Like usual plans changed, instead of a micro turbine build into a custom bike frame, I pivoted and am building a turbo based gas producer and its going into an offroad kart frame. I chose offroad because I have lots of country around me and I feel it'll get used more/ more fun not being limited to only smooth pavement. 

Turbo will be a journal bearing gt4294 running the same 70mm compressor I was already planning on using. 

Combustor will be reverse flow,case will be 7" fire extinguisher, flametube is 5" outer liner, 3" inner liner, 6" in length. 

Spent the day modeling an intake manifold to try and get a compact way to get the most smooth and efficient flow over the liner as possible. It will be investment cast out of either stainless or regular steel. 

Power turbine is the same modified hp841 freepower unit that will be coupled to the karts cvt fwd/reverse transmission. 

[dieselguy86]

Not related to this build, but I just got in kts wheel #6004, a 122mm x 151mm beast of a compressor, couldn't help but to slip it onto the mixed flow gtb62 turbine.






Cast compressor is 75mm borg warner wheel, the other billet wheel is a 94mm off a gtx5533r. 

[racket]

Hi Joe

Yep , its a nice match :-)

There is an engine being built by a JATO Member using that rotor , thanks to your fortunate finding of that turb wheel .

Cheers
John

[turboron]

All, google does not reveal any path to buy the mixed flow gtb62 turbine rotor. What is sourcing information and price?

Thanks, Ron

[dieselguy86]

Ron,

I found them on ebay, I was lucky to get mine for $250 cause after that they went up to $750.

Spent some time in the shop tonight, I was hoping I could get the kart to start before I tore it all apart, but when it wouldn't start even with ether I knew something was damaged. Stripped the head off and the piston was junk.


So got the engine/ trans ripped out to see what I was working with. I hoped the engine was a seperate casing than the transmission was, it wasn't. I have half a case I need to machine off before I figure out how to adapt the hp841 gearbox to it. 

Then there's the hp841 I have to figure out as well. The output is a 17 tooth starter gear that does me no good. It looked like it was held on by a bolt so I popped it off. Under the bolt is a thick washer, and it does not want to move. I ended up hearing it cherry red and got a chisel to bite into it and it popped off. It's recessed and probably press fit, explaining why it was so hard to get off. 


But that was the easy part, the hard part was the gear. They didn't want it going anywhere. I heated it up to a dark blue and it took several beatings to get it to pop off. One off, here's the output you have to work with...


1" shaft,  18 spline, which is kind of hard to find, but I only spent 15 min browsing. I need to go from that to about a 15mm shaft for the cvt transmission primary clutch. I'll probably end up machining the shaft myself and find a gear cutter that can cut the splines for me. Unless anyone has a better idea. 

[monty]

Mar 10, 2022 23:03:52 GMT -5 dieselguy86 said:

Ron,

I found them on ebay, I was lucky to get mine for $250 cause after that they went up to $750.

Spent some time in the shop tonight, I was hoping I could get the kart to start before I tore it all apart, but when it wouldn't start even with ether I knew something was damaged. Stripped the head off and the piston was junk.


So got the engine/ trans ripped out to see what I was working with. I hoped the engine was a seperate casing than the transmission was, it wasn't. I have half a case I need to machine off before I figure out how to adapt the hp841 gearbox to it. 

Then there's the hp841 I have to figure out as well. The output is a 17 tooth starter gear that does me no good. It looked like it was held on by a bolt so I popped it off. Under the bolt is a thick washer, and it does not want to move. I ended up hearing it cherry red and got a chisel to bite into it and it popped off. It's recessed and probably press fit, explaining why it was so hard to get off. 


But that was the easy part, the hard part was the gear. They didn't want it going anywhere. I heated it up to a dark blue and it took several beatings to get it to pop off. One off, here's the output you have to work with...


1" shaft,  18 spline, which is kind of hard to find, but I only spent 15 min browsing. I need to go from that to about a 15mm shaft for the cvt transmission primary clutch. I'll probably end up machining the shaft myself and find a gear cutter that can cut the splines for me. Unless anyone has a better idea. 

Hi Joe,

If you are lucky, it's a standard spline, and you can buy spline stock...both male and female. Unfortunately in my experience many manufacturers use custom splines to make it more difficult for people to make aftermarket parts.

A rotary broach spline cutter is the least expensive way to make female splines. Still going to be about $1K if you don't have a rotary broach holder. The cutters, even custom aren't too bad: around $200.

What equipment do you have access to?

Monty

[dieselguy86]

Hi Monty,

I don't have access to much, I have a manual lathe is all. Buddy of mine has cnc lathes and mills, I can ask if he has a rotary broach holder.

If I could cut the splines myself that would be great.

[monty]

Mar 11, 2022 8:58:45 GMT -5 dieselguy86 said:

Hi Monty,

I don't have access to much, I have a manual lathe is all. Buddy of mine has cnc lathes and mills, I can ask if he has a rotary broach holder.

If I could cut the splines myself that would be great.

Joe,

This company can make the broach for you.

You might be able to put the broach holder in the chuck and feed with the carriage, or use the tailstock, depends on how long the shaft is. You might also be able to turn this around and rotate the work. I'm not as sure about that.

Monty

[monty]

Looks like you can put the work in the spindle, so you should be able to do this on your lathe.

Monty