Steve, just a couple random thoughts on intake puffs. Please don’t take them for thruths. They are only feelings and guesses from my part, based on a mix of my own experiences and what others shared.
Different engines behave differently. As far as I know I never had an intake puff on my first two rigs. The third one is another story. Apart from that it seems a few things can worsen the situation.
Leaks, condensation, soot, tary fumes or a combination of two or more of them.
Tary fumes are less likely since your rig is a charcoal machine - unless you happened to feed it brands.
I don’t think dry soot will cause puffs, unless some larger flakes let go and interfere with an intake valve. Soot in combination with condensation makes it stick and can let go when dried out.
Early burning leaks could create condensation downstream in the system (and delutes the gas with CO2), even if the gas is dry to begin with.
Leaks in general delute the gas, but that’s obvious.
I have no experience with charcoal gasifiers, so I won’t go into anything like worn nozzles creating not focused enough heat, ash content in the charcoal, fuel size or anything like that. Just rambling…
Thank you Bob, Don, Goran, Kristijan, Tom, Wayne, and JO. Sounds like it may be the result of a leak. Kristijan and Tom, were a bit more creative in their diagnosis of “leaks.” Ha! Ha! I have already done leak tests on the gasifier. The only thing I didn’t check thoroughly was the gas line from the back to the engine. I was wondering if it could be engine valve problems. I hope not. Other things I can fix. One think I didn’t mention was that when cold weather arrived this fall, I put a piece on the carburetor to hold the choke open. The rash of intake pops occurred after that, but the difficulty starting has been going on for at least six months. I’ll test the gas line and put the choke back like it was and let you know the results. Thanks for your input.
JO described it well. In my experiances, weak gas or lean mix are most likely culprits for puffs. Both the resault of leaks, but dependant on leak position (as JO sayd).
I think SteveU once descriced what causes the popps, fuel burning so slow it still burns at the next stroke or something like that.
I dubt its a valve problem thugh. I had the same problem on my BCS walkbehind, it kept popping and throwing the filter lid off and l culdnt find the problem for weeks. Torn down the engine, polished the valves, no better. Then l found it, a crack in the hot part of the gasifier. A LEAK.
A good practice thugh l learnt from Tone is to pour some oil down the intake just before you kill the engine, if you plan to not run it for a while. Snowmobile guys did it all the time here but l never thod about using that in our feald also.
Update: Today I checked the 18 foot sump pump hose for leaks and found three small holes which I sealed up with electrical tape. Then I tested the 5 foot long, 2 inch galvanized flex exhaust pipe. Turns out that it was held together by rust. That is obviously the source of the toublesome leaks. I have enough flex exhaust to replace it a couple of times, then I’ll need to find something more permanent. The experts unanimous diagnosis was correct. Thanks again for your input. I expect to be “on the road again” next week.
The way the gas line, blower, and filter are arranged, I only need one valve, the air mixture valve which is located on the left side of the T fitting on top of the carburetor.
I will try to upload the latest brochure here. The photos shown above have been included along with some text update, and an updated drawing of the gasifier.
Thanks Steve. Great videos.
We used to have lots of Corollas about that age, but it’s probably the only one I’ve seen with an auto trans. Also, it’s the only one I’ve seen with a charcoal gasifier Very nice build.
Very neat and clean job you have done . If we ever show up at the same place hopefully there will be a barn or bushes to park my old truck out of sight .
I have thought about making some sort of system that would spray more or less water in there proportional to air flow, sort of like a carburetor. Has anyone tried this?
Rindert
I’ve thought about it a lot, but I wouldn’t know where to start on the jet sizing for the water. I’ve modeled up and 3D printed a Venturi big enough for the air intake on one of my flute nozzles, though the original intent was for a gas mixing chamber. I’d either need to cast it in brass and ideally pipe thread it, or something along those lines. I’ve got awfully hard water so I can’t help but feel like the jet would clog over time.
We have hard water were I live too. I regularly use a spray bottle to add water to foundry molding sand. I have worn out a bunch of these spray bottles, but the nozzles don’t clog. I think about those hand pump mosquito foggers they had when I was a kid. Simple. That hard part will be to get it to spray the right amount. Controls: automotive mass air flow sensor plus arduino. Probem: microbial growth. Might have to use windshield cleaning fluid. Come to think of it maybe automotive parts: windshield fluid tank, pump, tubing, nozzle. Then control the 12VDC pump via mass air flow sensor and duino. Don’t ever let it run dry because the pump motor is cooled by the fluid. Just thinking at this point.
Rindert
Thanks JO, Wayne, Giorgio, and Don for your kind comments on the videos. Thanks also to Cody who generously provided the sheep’s wool addition to my filtering system.
I think I’d prefer the mechanical method, and what I should probably do is see exactly what the CFM of flow the flute nozzles is pulling on, because I wouldn’t know what all the system resistance would take away from the engine CFM.
After figuring out an average CFM I’d find a vacuum motor that could do the same and play around with jet sizes until it equals the amount of water over a given amount of time compared to 1-2 drops per second.
The water tank would either need to be on the floor beneath the nozzle, or have a needle and seat with a float going to a bigger tank. I guess to condition the water I could just add a little citric acid to negate the calcium, or just make it so I can clear the jet with a wire every so often.
Our water is so mineral rich, I had a friend with an iron deficiency that would come fill up a 5 gallon bubbler/water cooler jug once a week for himself.
Very nice build.