Many elements have been brought forth now.
The most thermal efficient IC engines are now thermal coating the piston crowns. and some the in-head combustion chambers.
Balancing multi-individual power inputs has always been a problem. Horse teams. Dog teams. Human teams. Multi-cylinder engines. One of the valid criticisms to the 1st generation small block Chevy V-8’s was the side by side exhausts. Leading to weird lengths of intake runners. These criticisms were made by fellow GM, Buick-Oldsmobile-Pontiac V-8 designers. Overall simplicity in real work usages always wins out over idealism. And still kept simple; corrected; later in the 3rd and 4th gen Chevy small blocks. B-O-P engines all gone bye-bye.
Always to keep it useable, relevant, real world useable the test will be the work it supplies for a broad base of users. You all.
Why I value W.K’s, J.O’s, KirstijanL’s, Tone and others mobile/using woodgas developments much higher than any Lab-Ratting purity. Sorry. I cannot ever see engine dynoing as any other than Lab-ratting. Drag racing the same ratting. Circle tracks racing the same ratting. The race for Life goes on for years and years. That is the only true test.
Others actually daily IC engine electrical generating and using; are where the real relevant woodgas working knowledge is being expanded also. Different circumstances of only one-two fixed speeds lead to optimizing some engine factors.
Here based on Uncle Tony’s comparison of his experiences with vapor fuels and hydrogen (gaseous methane and to an extent propane too): versus liquids fuels of gasoline, nitromethane (and diesel/heavy oils fuels) I will now be thinking differently.
I will no longer think and say in terms of Fast combustion flame fronts, versus Slow combustion speeds flame fronts.
I will think in terms of Quickly to fully combusted; versus Slower to completely combusted.
So on another topic why I said favor bigger bore, versus shorter stroke engines for woodgas.
Hemi; semi-hemispherical and penta shaped combustion chambers.
Ha! Ha! You can never have it all using existing engines.
And that is the most important lesson. When you can’t have the one you would ideally Love . . . then love the one you got.
Steve unruh
[quote=“Steve Unruh, post:441, topic:6456, username:SteveUnruh”]
I will no longer think and say in terms of Fast combustion flame fronts, versus Slow combustion speeds flame fronts.
I will think in terms of Quickly to fully combusted; versus Slower to completely combusted.
So on another topic why I said favor bigger bore, versus shorter stroke engines for woodgas.
Hemi; semi-hemispherical and penta shaped combustion chambers.
[/quote
You should not be comparing fuels that bring oxygen to the mix like methanol and nitro methane to fuels that bring a large inert component like wood gas
Cooler burning I also would like add
Uncle Tony leaves some things half said
Speaking from personal experience with methanol motors and a little tinkering with nitro
Long rods, long strokes moderate rpm
A slant 6 225 is and excellent engine because it ticks boxes
If you have a knock sensor in your engine that you can go with shorter strokes and rods with higher rpm
What you want to avoid is a situation where the piston is moving faster than your fuel can effectively light and burn and push
Or you can fiddle with your time as you drive you already are adjusting the carb as you drive
And your not going gain much from compression beyond about 10 1
Demissipning returns
There is some valid to what you say Wallace.
Nope I’ve never used any self-oxygenated engine fuels except for E-10 to E-85.
And as tempting as methanol would seem to some woodgassers and has for years. Others actually using this neat in engines say, “Wait a minute. Lots and lots of storage and materials handling downsides to methanol.”
Small bore and long stroke have been used very favorably by many engine manufacturers over the decades 1960’s very favorably. VW, European Fords, many of the Japanese and English engine manufacturers. For gasoline. For pump spec grade diesel.
Remember those long strokes having to cycle the piston up and down farther and so have to have higher piston speeds to complete the cycles. High carbons fuels like gasoline and diesel can make the high-speed flame fronts to long-push. Need the time-in-cycle for as full of complete combustion as possible.
There are valid reasons the big generator companies like Onan and other did use the bigger bore versus stoke engines of Fords I-4’s and I-6’s in their propane and methane generator sets. Even the GM cast Iron Duke’s and later I-4’s were used.
Few to none used the excellent Chrysler slant 6’s in quicker to complete combustion gaseous fueled applications. (The excellence of the slant-6 a whole 'nother topic due to having a long skirt heavier stiffer block; only having five main bearings and overall excellent experienced Chrysler metallurgy choices.)
And the guys actually engine power using true made woodgasses who are static compression boosting are saying true all season broad use performance begins at 11 to 1, and can go up to 14 to 1.
Then ignition timing changes do not have to be so extreme.
Gasoline and diesel fuels in IC engines are boxing round house punches. MMA long sweep high delivery kicks.
Woodgas is a straight on series of lighting punch-jabs. Repetitive quick kicks to the knees. Not fancy, tires smoking, showy. But cumulative wear downs.
Woodgas is an endurance fuel.
Steve unruh
Hmm. Yes your chart. Obviously not done for diesel or heavy oil fuels.
Wallace refer to the in the library here for C/R engine power charts done by the India Institute for Technology; Combustion Propulsion and Gasification Lab for producer gas.
Effectiveness begins at 11 to 1. Gets much better at 13 to 1. Peaking at 17 to 1. These were crankshaft pressures measured at degrees of angle.
Ha! Ha! Hard to keep this topic focused on the Inside an (piston) Internal Combustion Engine. Even for me.
You are correct. Outside, secondary conditions will override and dominate.
You say release the engine of gasifier train flows pumping. Sure. Be very complex and a whole setting up, building, and controlling; then maintaining project in its own right. You are re-creating Mazda’s SkyActive systems.
And I’ll say that the easier seamless way to get more engine power on woodgas is to release the need for extreme ignition timing jacking around by static compression raising.
You know from your racing experiences this is hard to set up a true variable 45-60 degrees ignition timing on single cylinder engine, which were meant to be fixed timing engines. Engines as in small electrical generators.
The V-8 distributor ignition guys fight going past 45 degrees. The V-6 distributor guys fight timing too.
ALL with distributor-less: the guy’s groan having to re-map program ignition timings or are just flat unable. And unable to get any to do this for them.
So . . . pick your battle, for the best result, you can do, says I.
S.U.
I can even tell you what engine they used for testing.
It was an RB33.
I know this because I have a DM10 ( single cylinder version of that engine )
Diesel is apples and oranges you are not going to hot rod it to get the compression up that high.
But you are going to dilute the incoming charge with a lot of excess nitrogen and CO2.
Again boosting is going to get you your power back and not compression.
The factory comrpession ratio of an RB33 is 17:1
Thats as far as they researched.
Now if you ask the folks at Arrow oil field engines about their natural gas version of the Petter and son PH series you might get some interesting insights too.
But that experiment when so bad they don’t even tell you they sell parts for the K series anymore.
The DM10 with the rocker box head and the Petters style injector
The K series.
PROOF you should take Indian engineering and advice at face value.
No way a DM14 can put out enough power to drive a 15 kva head.
Thats a 116 stroke 120mm bore version of the Petter PHW-1 built under a 1947 licence.
That Petters design ( and the RB33 that evolved from it ) has a huge deflector cast into the intake port to cause turbulence ( and a huge cup shaped piston for the same reasons)
It needs a lot of turbulence to get the fuel to burn clean.
The CUB diesel was even worse so Petters changed the injector angle and location ( and KOEL did a third time on the RB series ).
They smoke burn dirty and don’t cold start well.
Add a little propane of in our case woodgas and they improve in both emissions and efficiency because the effect of having a dilute flammable gas in the engine at the same time fuel is injected helps improve combustion.
A different diesel by a different company may not behave the same.
I also want to bring up Arrow not even pretending to support the spark ignition version of this engine running dilute oil field well head gas.
What went wrong here and why doesn’t anyone talk about it?
I cant answer all these questions.
But I can tell you to be wary of data from India…
PJ-30 marine diesel.
I should show a real Petter.
Don’t get me wrong they are a great engine.
Just dirty, not a real nice cold starting machine.
You would curse one in the bush in winter
You will get no dispute from me about India engines “dreams” often going just wet and sticky.
I bought and owned a 12-1 Made(ONLY)-in-India Listeroid clone engine. 6 1/8" bore by the standard 4 1/2" stroke. The British Lister Company only ever took their CS design series out to a 4 1/2" bore, 8 horsepower at 1000 RPM. The piston counter-forces just became too great going larger. Lister then went with multi-cylinders at higher RPMs to get the same power in lighter, less earth-shaking packages.
My point is you are blindsiding yourself with these India based failures engines.
Mitsubishi and Kubota of Japan do make coking plant off-gas fueled piston engines. Landfill off gas engines that work just fine. Neither by any means; pure gaseous fuels with consistency.
Natually aspirated. Higher compressions than your 10 to 1 limit.
Kubota’s were DG672’s and DG1005’s.
Both were widely used around the world. Out of production now as not worth upgrading to the newer lets-force-all-IC-engines-impossible Tier 4 and EU equivalent regulations.
The DG1005 was used a lot on woodgas by Victory Gas Works. I’ve hands-on these.
So just like for gasoline 14 to 1 air-fuel IS NOT the best for power, or economy fuel air ratio; but the sweet spot for HC’s, CO, NOX emissions as conditioned by an expensive rare metal’s catalytic converter . . .
Gaseous and diesel engine manufactures are forced to be the Dog getting regulations Tails wagged a lot. Regardless of the intended fuel type.
Design to comply or be out of the engine manufacturing business.
So again, an outside secondary factor Commands. Overriding what would be fuels use the most direct simplest use solutions.
Fortunately, DIY for just ourselves we can do direct, simple systems. Scofflaws All we be.
Turbo-me-not Steve Unruh
(why? I’ve been the pud having to keep old worn bearings and seals leaking coolant and oil factory turbo systems running. $$$$, or junk out the car, pickup)
I haven’t seen any discussion of dual spark plugs in woodgas fueled engines. Has anyone tried drilling and tapping a second spark plug into their engine head(s)?
The theory behind dual spark plugs in regular engines is that they more completely combust the fuel and with two flame fronts it all happens faster. In regular engines on regular fuel the benefits are slight. High RPM two strokes seem to see some benefit though. But maybe for a slower burning fuel like wood/chargas we would also see an advantage? Especially in terms of a higher RPM ceiling?
Curious if anyone has tried this… higher RPMs is the easiest way to get more power out of a given displacement.
Two relatively wide spread use IC pistons factory engines were dual spark plug.
One of the Nissan four cylinders. And the 90’s Ford Rangers 2.4 four cylinders.
The Rangers have been done on woodgas. And at least one of the dual plug Nissans in a pickup. Dual spark plugs did not seem to have turned them into gasoline equivalent engines.
And some have added MSD modules to their ignitions. Multiple Spark Discharge. It capacitor loads, then coil discharges and refires the spark plug every 20 milliseconds. Smoother running. But still no gasoline equivalent power.
Raised compression ratio, across different IC engine types is what has helped the most.
Some engines like a single cylinder air cooled this is easy, easy to do. Inline water cooled this is easier, possible too.
S.U.
Nissan Z motors were kick ass! 7000 rpm redline.
Yep dual plugs, but the second plug didn’t fire during the power stroke, so that would have to get sorted out.
Nostalgia trip…I had those 720 Datsun FWD pickups here…go anywhere for cheap. I miss them. The kingcab let the seat go back far enough for big people to ride in.
I was thinking about this dual sparkplug just the other day. I too think a woodgas engine might bennefit from it. But lm with Steve. From all l tryed so far, raising the compression helps most. Having more valves per cyl helps too
I have one of those, a ford ranger, 1991. Lost spark system fires in both the power and exhaust stroke. It’s a good system. A lot of magneto ignition engines also work that way.
Some people say you can swap the ignition wires around so that both plugs fire in the power stroke. This is supposed to give better mpg, but I didn’t see any change so I put it back the way it was.
Rindert
I went looking for my Reigels industrial chemistry book, and found my 1940 Dykes Automotive Encyclopedia. Sir Harry Ricardo, apparently, had something going with Waukesha back in the day…what is old is new, looking at you 6.2 Detroit IDI, and IH 6.9 IDI !!!
I just found this in old technical litterature, a engine special built for running on gas made from coal or coke, (gasengines never become popular in Sweden because of no sources of natural gas, all city-gas was made from imported coal.)
Anyway, this engine was made around 1910-1920, by engineer Svedlund (older brother of Axel Svedlund, the woodgas-engineer!)
It seems to prove the theories about long stroke/long conrod, beneficial for woodgas.
Ofcourse, engines of this time had long stroke/ long con-rods, but this seems to take it to the “extremes”, even the description in the book talks about the long stroke of this 4cylinder, 6liter engine.
You are close if @Wayne was asking how much energy the vacuum robbed from the engine.
Scientists define work (W) to be the product of force acting through a distance. For a gas, work is the product of the pressure (p) and the volume **(V)**during a change of volume.
delta W = p * delta V
Once you have work, you can work convert it to foot/lbs, then to HP loss. HP is the rate at which work is being done (or not done in this case).
Guys, l dont know if this video was alredy debated here, but l find it most interesting.
We do burn 20% of hydrogen in our fuel so lm sure a lot about this applyes to us. And l just love this guy, he knows his stuff and throws facts out like no tomorow.
Per instance, what struck me most was the point where flame front stops at a wall. Crazy difference compared to petrol. Woodgas backfires now make a lot more sence to me. And lack of them on my newly polished valves on the Škoda. I think from now on l will include a valve job in any woodgas project.
Secondly, this comfirms my theory of why we see best power runing lean. Because of hydrogens wide ignition range, we bennefit the larger cyl filling ratio more by leting in more air.
