Addictions are horribly $$$$'s draining alright.
Opportunities passed up never to happen again.
Good people loving you shouldered aside, having to move on with their lives. Normal in-balance people.
In-recovery adrenaline junky am I. The rushes from pushing to almost dying. Nothing like it.
Ha! Happy to talk big block. We have 2 454s here and a 366.
I was thinking that the ideal wood gas engine can be divided into two theoretical parts. The first part is making the best air pump possible. One has to make the easiest possible route for the air and gas to fall into the cylinders. No restrictions. That means all these screens and filters have to do their jobs without pressure loss. No 90° sharp bends (bad Farmall, bad!). Tuned intake runners and vacuum pulse exhaust. Yep power band.
Some notes to remember…it’s not high vacuum that makes a gas producer work well, it’s high gas throughput. A high gas velocity to impinge that ash off and keep that carbon white hot ( or at least orange, in the case of the tar makers).
Vacuum is a tricky thing. We forget there were originally two types of internal combustion speed controls. Charge governed and throttle governed. Hit and miss engines are charge governed. They get a full charge into the cylinder for each power stroke. When they reach a certain RPM the governor opens the exhaust valve and stops the ignition, and the engine coasts back down to a speed where the exhaust valve is closed again and the ignition turns on and it gets a full air fuel mixture charge in the cylinder. There is very little vacuum.
Throttle governed engines use a plate or a slide to literally cut off the air to the engine. By giving the engine a partial charge control of the RPM is achieved. The downside of this that no one thinks about, is that saying you have a 12 to 1 compression ratio is only true if you have no vacuum. The dynamic compression ratio of an engine depends on how closed the throttle plate is and how much of a charge the engine gets. Seeing as most automotive engines cannot run wide open throttle for more than a few minutes without overheating (looking at you Cadillac 472 and 500!)
So, knowing all of the above, the question becomes do you need more power than what your engine provides at full throttle. So if you’re going down the freeway and you’ve got the throttle mashed to the firewall and you don’t have enough speed, then you should start looking at turbos and supercharging etc. But if you’re only using half throttle, all the rest of this stuff is ridiculous. I say that because everybody on this wood gas list that’s driving a vehicle powered by wood, brags constantly that they are using free fuel. So you really don’t give a crap about efficiency as long as the fuel is free. That’s why we still have the b-52s with the original engines.
So, the first part is having the best air pump you can make so the volumetric efficiency is at max. That’s the low hanging fruit.
The second part is the chemical reactor part…stay tuned for part II…
I keep posting this graph because it is absolutely fascinating.
The first thing to notice, that blows me away…the middle graph shows the piston speed maxes out at ~80° or just before halfway down the cylinder. I always visualized the speed maxing out at the halfway point.
What does it mean? It means the chemical reaction, the burning of Woodgas and oxygen, has to be happening fast up to 80° because the piston is accelerating away, expanding the volume, releasing the pressure, cooling the burning.
Right about at that 80° point, the crank shaft leverage is at its most favorable. Also the piston acceleration goes to zero. (F=MA, with A going to 0, the force opposing the flame expansion becomes undefined.) The weird thing is, at this point the piston begins decelerating, shedding speed, allowing the flame front to sort of catch up, just when it’s starting to peter out.
What of all this? Steve is rolling his eyes! It means that whatever burning you are going to do, you better do it from top dead center until max piston speed @~80°, after that it would be nice to have a lot of pressure to move the piston the rest of the way down.
So all you cam people, and spark advance people need to cook up the best way to have the max amount of mixture in the cylinder burning at max flame speed by top dead center. If not, the mechanism is fighting you.
Does the ideal Woodgas engine have an old school T head? Or like a flat head? Move the spark plug away from the intake valve, so you can start the fire while the intake valve is still open, and the incoming charge is ramming in from momentum? Think slower flame speed, so you have time.
The one thing we have to unthink is detonation. Yay! The eighties are gone and this fuel will not detonate ever, and if it did, so what! It just more force.
I am thinking short stroke. Look at the top graph. The longer the stroke, the longer the flat acceleration period, where the mechanism is useless, while the period where the acceleration is changing rapidly, is very short and vicious. The faster the piston falls away from the flame, the less power you make.
The long stroke on the Farmall gets by with this because the engine maxes out at 1000rpm.
Imbedded in this video description is a Wolfram offset slider crank demonstration. I think you can download it to your computer and play with various crank offsets and connecting rod lengths, which would allow you to find the optimal setup for wood gas flame speed.
Ps I have Wolfram on my raspberry pi, so not sure about you non Debian people.
Nope BruceJ. I am mile wide smiling.
I have these same engine books . . . mostly.
I somehow lost track of a “High Performance Motors Fuels” book that covered this all better than the engine books.
Fellows, cursor sweep over his graphs, and they name to explain.
You are right. A rapid pressure building up milliseconds whoosh into an expanding space. (Actually, that part of it is the same as in a primer liting off the cartridge power burn started the pressure pulse building up pushing against a bullet that must get moving making an expanded combustion space to limit that pressure from going excessive.)
In the IC engine the applied combustion burning increasing pressure force versus effective crank angle is critical. Give way to moderate the pressure.
Effnecnecy engine use up crank turning most of the pressure with just enough residual to assist getting the gases out of the cylinder.
Max power engine over fuel to maintain a real blow it out pressure. Jack up the rpms to get back to another power push asap.
Back to the poor firearms comparison the magnum revolvers blowing out the barrel still burning powered kernels.
Woodgas I agree short stoke, but LONG rod. Hey, hey, your Old Ford FE’s you love.
Not so much a Ford 302 short stroke short rod.
But Bruce increasing the static compression ratio speeds up all fuel combustion speeds rates. Then as proven, woodgas ain’t so “slow” anymore. A dynamic factor.
We goona’ get to piston crown shapes and combustion chamber shapes too? Yes. Yes. Please. Please.
Hmmm, oh boy, hmmmm…and a C-6…brb…I gotta go study.
What are your thoughts on the piston shapes?
The big boy gaseous engine manufactures all use a flat cylinder heads with four valves. The actual combustion chamber is mostly in a deep cupped piston crown. Minimizing heat lost transfers I figure. Heat making gas expansion is the name of the game. Heat losses into coolants, oils, exhaust count against.
The Kubota DG672 and DG1005? factory methane converted engines retained the diesels three scooped injector spray swirling piston crowns and have a very shallow combustion chamber in their labeled “Special Methane cylinder Heads”. ~11.5/1 liquid cc measured c.r.
Realize these are all fixed RPM applications.
Mobile rpm is dynamic, changing the game some.
Like the Kubota conversions we will be locked in a lot to pre-existing.
I, being the “if it ain’t broke don’t fix it” kind of mechanic, have never actually looked at the FE/FT specs…a 360 is just a short stroke 390.
I bet, back in the day, I had some of those bigger engines too. I have two in a boat, I want to retrieve as well. I was told they turn in opposite directions…how to tell them apart? Hmmm
360 versus 390? I’ve been told by the block height. Like the inline 250 versus longer stoke 292. That’s easy. The V-8’s I could never develop, the knack.
CW versus CCW? The way the vacuum advance stick out of the distributor. If the marine even have vacuum advances. Failing that pull the starters. The drive gear teeth entry angle and overrunning clutch will be reversed. One starter running back wards.
Hey William we drifted on you. We do that. Interesting thing show up in those rabbit holes.
Here are some previous 454’s gasifed out to running and using.
So been done successfully:
The next read for maybe what to avoid:
A few more in the DOW archives but either never completed or light weight 1/2 ton or cars not really applicable for your heavy fast towing wants.
There were a few Ford 454 builds on DOW about 10 years ago, Then people got more interested in Dakotas. There were discussions of big blocks on the yahoo groups back at the time.
Is this what you need to put a car manifold on a tall deck BB Chevy?
My 366, has a Rochester 2G.
When you first showed me those diagrams I didn’t know what they represented Bruce. Good to hear the further explanation even if most of it goes over my head. I do want to talk about piston shape. I still say that without some visual means to see how wood gas actually burns in a cylinder we lack sufficient data to determine optimum piston shape. We know, from the project farm demos, that less volatile fuels tend to ignite and then spread relatively slowly across the surface of the piston building pressure as they ignite. When you add oxy into any fuel it will burn faster with more pressure. It seems to me that it is much harder to move more oxy into wood gas than almost any other fuel. Less oxy, less power. That’s why cylinder volume becomes important. Bruce’s bigger bore. In my mind, the issue with bigger bore is that a low power fuel that tends to burn in a path across a piston takes longer to reach maximum pressure. A crowned piston further increases that surface area the flame path must follow unless you are using a hemispherical head where the ignition point is center of the piston crown so that burn is equal down both sides of the piston slope. Firing that spark at any other point in that combustion chamber and you sacrifice a lot of power. I’m totally open to other views and never have had the chance before to discuss things like this with knowledgeable people. I’m still leaning toward longer stroke, smaller bore. I’m thinking that a punch from a fist is better than a slap from an open hand.
Tom, and all,
Please believe me when I say I am from the “run what you brung” camp. I only talk about building a hypothetical engine. In practice, I would use existing parts to build a Woodgas-ish engine. The hard part is going back to the fundamentals. In my studies, the work just prior and during world war one by sir Harry Ricardo, surmises what we have today. Prior to that, the internal combustion engine WAS predominantly running on producer gas. I believe we have to look there to how best to build or adapt a modern engine.
I think we have to start here, with tetraethyl lead.
“…General Motors patented the use of TEL as an antiknock agent and used the name “Ethyl” that had been proposed by Kettering in its marketing materials, thereby avoiding the negative connotation of the word “lead”. Early research into “engine knocking” (also called “pinging” or “pinking”) was also led by A.H. Gibson and Harry Ricardo in England…”
Every automotive engine that ever burned gasoline has been designed around detonation. Too much compression, the wrong spark plug placement, having a hot spot in the combustion chamber all made detonation. Detonation is interesting. It is the near simultaneous rise in pressure through out the combustion volume. This pressure wave, when involving gasoline and oxygen, is considered an explosion. Some detonation is the clashing of two simultaneous pressure waves meeting. No matter how it happens, when gasoline (with 89 times more power then dynamite) detonates, it will destroy an engine in a very short time.
Woodgas will not detonate. Look at it’s composition. The air/fuel ratio is 1/1. The woodgas is 40% nitrogen, and the air is 77% nitrogen. Most of the gas in the charge is inert. So the combustion has to sneak around these blocking nitrogen molecules. They are N2 (diatomic) and are just as big as carbon monoxide molecules.
I say we should revisit how we think about arranging the piston shape, combustion chamber shape, and spark plug placement, inorder to encourage detonation (extreme rapid burning).
As Tom says, high compression is expensive. It’s also costly in pumping losses. I think there are many other low hanging fruit to be picked first.
Just being involved in this discussion is making me as happy as a puppy with two peters.
Hang in there WilliamW. , this will all come back to your core choice, which-one-to- woodgas decisions.
TomH and BruceJ great post you put up.
On engines, combustion chambers, piston crowns shapes, bore/stroke & rod length/crank throw ratios every engine designer taking it out to manufacturing first must select a primary favored fuel.
Once that is prioritized then they are stuck, just as us, with the basics adapting it to another fuel type. The initial compromises they had to make, pale compared to the fuel adaptation compromises they then have to accept later.
Ha! For gasoline fuel Hemi-combustion chamber the best? Or turbulence inducing reduced quenching area Wedge combustion chamber? Or?? Tom you gonna’ piss stones reading this one . . . the weirdest, rarest of the bunch in the GM/Chevy small kidney with an intentional sharp shear edge?? Pulled a sisters Chevy-Geo Metro cylinder head. What!? A Chevy kidney combustion chamber! Where is my “better” Suzuki hemi-head? Ha! They both made power and mileages alright. The Chevy-kidney had lower unburned hydrocarbons in the gasoline fueled exhaust.
So mainline engine manufactures still promoting, and making as better, these different overhead valve combustion chambers .
Nobody. Nobody, makes up new designs valve in block T, I flat-heads anymore. Limited c.r.'s possible before you choke even off worse the flows. Torturous, long convoluted flows pathways. Just too much heats robbing not-directly over the piston surface areas in those.
Chevy sixes ditched out of those in the 1920’s. Even many for the better farm tractor engines like Case iron wheeled moved on to much better overhead valves. Why on into the late 1950’s (Rambler sixes) flatheads. Costs to redesign and retool.
Three approaches to selecting a better to be woodgases engine.
No replacement for displacement.
WayneK first did some big block Fords. 1, 2, were 460’s. He wanted more towing power. Him an avowed Ford guy, studied and then swithed over to the large displacement Dodge V-10’s. Kept his ohv, pushrods, rocker arms, cam-in-block simplicity. Got a surprise that the Chrysler/Dodge distributor-less was giving him no hands ignition timing changes.
He still recommends Ford 460’s. Chevy 454’s. Dodge 440’s. Dodge 318’s and 360’s in the smaller, better, hp-to-weight ratio hyway speeds rigs.
The replacement for displacement is higher compression ratios.
All of the historic make-better woodgas literature , those 1930’s and 40’s guys knew if they could just get above 5 to1, 6 to1 flatheads compressions to oooh-wow 8 to1, 9 to 1 compression ratios they’d zoom-zoom up in woodgas performances.
Wellie, well, well. These were the common factory compressions by the 1960’s and on.
Better even. Unbelievable to them back then of 10 to1, even 11 to 1 factory engines compression ratios factory made and sold.
The third approach - forced boosted induction of air and woodgas. When the 1940 and 1950’s gasoline racing, and military power engine guys wanted for-any-cost power that is what they did. Watch some of the military airplane guys on youtube and see this. late 1930’s, early WWII single boosted. By 1943-44 most all US, British, German and Soviet fighter aircraft were double boosting.
A fourth way not really viable. Practical. Or able to wide spread emulate. The dedicated gaseous single fuel engine approach. Idealized.
Tom you don’t know this. BruceJ can remember, think back to the 2007-2012 woodgas trying era and know that was me, and a bunch of others. Oversized 950 pound Lister design clone engines made in India. Or, cute as a bug little German design origin - tech transfer to thier ally 1940’s Japan Occupiers in China, left behind, copied/improved new-made Chineese clone engines. Changfa’s.
Boy was I ever dumb. One near $2,000 to get bought and shipped here. The literal running hopper needing a true 2200 pound, one-ton base to keep it from hop-walking away.
The other relatively inexpensive as third-hand, load into my trunk for $300.
Hey! Factory electric start. The wife would even turn key start it, stand within 10 feet of it.
No bloody parts available. No more 2nd, 3rd engines allowed imported, available for back up, and spare parts boning. Thanks Greens. Thanks EPA.
Yeah. I was sure dumb.
So Willian go for the 454 you already own, with readily available parts. Hotrod parts, and systems galore for it.
Added to my no-more never-again, of no-more flatheads; no more under-flywheels ignition points, is now no more large engine carburetors. The 1984 Ford F150 with the 300 cid feedback carburetor I gave away to a local 14 year old wrench turner. He got the older 74 Ford F250 camper special pick up 360/390 too. Towed away.
He had stopped wanting the 1994 Ford F150 302 as a preference; and would have given real cash money for it. No. No. That big bore, short stoke SEFI is mine. Mine. Half dead computer, it still starts and runs, ok, acceptable, still. And these been proven easy woodgased now.
I agree that in 36 posts we have beat Williams thread into the ground. Hell, that’s just how we roll. Can’t apologize. As far as optimum wood gas designed engine without access to a foundry or machine shop I am shifting back to the idea of creating a spark fired engine from maybe Marcus’s buddies 12 valve Cummings. It has everything you need except a way to sequentially spark the fuel.
I’m sure Steve’s got a cure for that one I bet you!
but yes William I believe your motor will be just fine on wood, but the only way to prove it is start building!
Look up Francois Pals working project pictures for the industrial engine off-shelf ignition systems, in-use. Individual coil-near-plug.
Altronic; MOTORTECH; Heinzmann; HOERBIGER; Gill Instruments for starters.
I think I see a new feature that should be added to this board. We need a “Select All” button for the little heart thingys. LOL. Every reply was appreciated and full of useful information. Thanks to all of you for being such a welcoming crowd!