Yeah… It ran at 3.2 kW for half an hour… It was a bit of a struggle, but we think the carb valve is too small. We’ll be bumping up the carb valve to double the size (with cold air intake filter too), and I think we can get a little more juice (maybe 4.0-4.2kW). But that’s with this engine… With a 14kW generator, we’re pretty sure it’ll do 7-8kW.
Bill,
It’s the same TIG cup nozzle system we’ve been using… no changes there. We haven’t adjusted the timing on the Honda yet, but with the H2 we think we’re producing, we might get more efficiency by retarding the timing a bit.
We are directly connected to the air intake on that Honda… Flanged. We’ll add the carb back on in a modified state next week. Yes, we went up to 3.2kW with an undersized ball-valve carb… it was a bit of a struggle.
With the right valve, some timing adjustments, I think we could do 4.0-4.2kW, sustained load… Give or take…
We’ll see 
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very nice! glad to see your latest work, so thanks for sharing.
what size of air inlet valve are you currently useing? i’ve always used 2 hp per Kw, and don’t expect more than that… looks to me like you’re in the ball park. Keep up the good work.
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Arvid, the nozzle is a 1-inch pipe with a TIG cup size 8 (which means 8/16", or 1/2"). The carb is a 3/8" ball valve, and I think we’ll be going up to a 3/4" valve with cold air intake filter.
I’d be happy at 4kW sustained load on a 7kW engine. Although H2 doesn’t really give us more power, so to speak, we get enough of it (I’m speculating) that we can start to retard the spark timing significantly on engines because of the flame ignition speed.
Lots of testing and tweaking still to come… Thanks!
yup, I would have suggested a 3/4" air inlet… looks like you have a plan. Keep it up.
Troy, how do you hold the TIG cup on to the 1 inch pipe?
Troy,
What Don said - but also, there are different types of size 8 cups, for different TIG torches. Specifically, what part number are you using to fit the 1" pipe?
Bottom graphic, first cup… 54N14-#8
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Don,
NPT threads… Easy peasy…
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Troy,
Not so easy - yet.
My #8 54N14 is too large for 3/8" NPT, too small for 1/2" NPT, and gets swallowed up by 1" NPT.
Also, local welding shop says that threads-per-inch (TPI) for TIG torches ranges from 16 up to 32, depending on the diameter.
NPT TPI is 14 for 1/2" and 3/4" pipe, and 11-1/2 for 1" pipe.
What am I doing wrong?
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Aughh, don’t say that Alex. Mine are on the way somewhere.
One minor clarification -
57xxxx series cups appear to be the correct diameter to fit a 3/4" pipe, but, as stated, the cup is designed for machine threads, rather than pipe threads.
I suppose you could cut a piece of unthreaded pipe and tap machine threads onto it.
Continuing to persevere . . .
Big apologies guys… I just spoke with Jared (fabricator), and you are correct… They are machine threads. We had the pipe threads machined at a machine shop.
Since I moved down to Mexico, and am not in the shop any longer, I am not on top of the fabrication details as I once was. I should have remembered this though, and with our first prototype, I bought an NPT to machine thread adaptor because of this very problem.
Again, apologies to anyone who spent money on what I said earlier… Sorry Don and Alex.
Apologies accepted Troy. We don’t let little things like this stop us! 
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No apologies needed, Troy. We appreciate and admire your work on this. I’ve been looking for an excuse to buy a tap and die set …
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I brought the cup I had in to Fastenal. They found the threads on mine to be metric machined threads.
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New Crossfire gasifiers are being shipped with an outer jacket air pre-heater / gas cooler… This modification was done to cool the gas, but we were very cognizant that the heated air might increase (or make more efficient) the water gas shift, by reducing condensation prior to the nozzle, and (perhaps) even help carry the atomized vapor across more incandescent carbon surface area…
Will keep you all posted on our findings…
We’re excited to be partnering with a seasoned electronics expert that will be building out our automation package. We’ll also (finally) have the resources, tools, and talent to capture more information and test various data points.
We’ll be building the automation package on Raspberry Pi (Linux)…
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Gone quiet again.
I have been watching you for a while now.
Since the open source days.
Very inspiring work.
You made mention of retarding timing.
I don’t think you want to do that.
If this was a normal gasoline engine I would play with the heat ranges and start looking at the the ground strap and shell electrode to tell me what sort of combustion chamber temperatures you are dealing with. The ground electrode in particular can tell you a lot about how much timing your running and if you need more or less.
You want to see some heat and discolouration in the elbow of the bend on the ground strap.
This would indicate to me you have about the right amount of timing.( for a gas engine this is uncharted territory but I would follow convention as a starting point )
Exhaust gas will tell you a lot about timing too.
If before you hear a ping you will start to see exhaust temperature drop
This is because the heat of the combustion is in contact with the inside of the engine longer than needed and the heat is starting to transfer to the cooling system
The ideal time is to have complete combustion ending just after TDC before 90 after TDC.
The place in crank angle is complicated, but you want most of your combustion done before 90 so you have maximum cylinder pressure at the best crank angle.
After 90 the pressure drops off fast and little power will be extracted from the expanding gas
My suggestion is get a timing light and some keys cut in 2 deg increments and run the test again watching you power output AND exhaust temperatures.
I think you are running a GX390 there too.
Options for that are a big bore Clone kit 440 with the stock head for more power and compression to get back to the name plate rating.
Usual speed shop tricks, improve the exhaust and do a mild port and polish.
Carefully consider your air inlet and gas mixer for the best flow
Swirl might help too, what you loose in a restriction might make for a more efficient engine at lower power levels.
If you are running a generator at less than the name plate rating you are wasting energy.
You want to be at rated power for maximum efficiency.
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Wallace, you may want to see my new post… Open Source is back on, and will be my sole focus. Thanks!