"Inventing" a "New Multi-Fuel Engine"

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oldMan99

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I just finished reading to the end (Page #2, Post #18) of the thread "Completely Random" where the OP was asking about why/how a multi fuel worked. (For reference, here is a link: http://www.steelsoldiers.com/alternative-fuels/68037-completely-random.html )

While reading that, and especially Wreckermans response where he said, (Loosely quoted) That perhaps in the not to distant future only multi-fuel Deuces would be on the roads. ("Insinuating" that either fuel would be prohibitively expensive or simply not available at all).

That got me to wondering about ..... the reason for this post. I was going to put it in that thread but I was afraid it would hi-jack it so I made this new one.

So....

If you wanted to take a modern engine and build it into a multi-fuel with more or less the same ability to successfully consume the same "Stuff" that the 60 year old Deuce can, what engine would you start with and what wold you have to do to it?

Along those lines we want this engine to remain as "Stock" as possible so that we can get parts for it. This means that we want to use a donor engine that is more or less readily available, not something that is rare or super expensive. For example, we don't want to use a 1980's Mopar. Yes parts are more or less available but you have to look hard to seek them out where as you can walk into anyplace that claims to sell auto parts and get parts for a Chevy 350.

In the process of building this power plant we want to use as many off the shelf parts as possible, and the more common they are the better. Remember, one of the key goals is to be able to maintain the engine for a long time in the future and keep in mind that normal supply chains my be interrupted/intermittent or even no longer operating at all so the more common and easy to find the parts the better.

The first question in the quest to do this would be do we use a gas or diesel engine as the starting point, and WHY? I am guessing diesel. If that is the case, Then I would ask about the feasibility of using the "Pre-computer" Cummins 5.9 or possibly the 4.? (I can't remember what the 4 cylinder size is). There are plenty of 5.9's around, parts are pretty easily accessible and they seem to be pretty solid, durable and should be able to withstand a fair amount of abuse. (I know the 4 cylinder is smaller and lighter, but are the parts as readily available? Would it make a better choice for our project?)

So, assuming that you do want to start with a diesel and that the 5.9 would be a good diesel choice, what must be done to it to get it to successfully, reliably and non-destructively, (It has to last) provide motive power to a 4x4 or 6x6 wheeled vehicle while using all or most of the same alternative fuels that a multi-fuel Deuce will burn??

Now, all of that said, if the donor choice would be gas over diesel, (Again, based on nothing but commonality and parts availability), what about the Chevy 350?

Is there a choice that would for some reason be far better than the 5.9 or 350? If so, what would you suggest and exactly what makes it a far better more easily adaptable and/or longer lasting choice for this application?

Disclaimer: I did try searching for this but either I used the wrong terms, I'm a retard, or there were no threads discussing it or some combination of the 3.

I am hoping this provides some real open discussion. If I get enough info and it seems feasible, I may (eventually) just try it just to see if it can be (reasonably and successfully) done. It would be pretty easy to build a test stand and run it for awhile to see it it really worked powering a generator or water pump and if so, put it in some vehicle just to see how it does on the road.
 
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TexAndy

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I don't know much about it, but I do know part of the reason the LDT-465 series is so successful at burning multiple types of fuel is the very high compression ratio.

How would you change the compression ratio of an engine? Shorter pistons? Can't imagine even doing that would change it by much.

However... I wonder if you could design a new engine based around a new block with deeper cylinders and use or modify components from other engines.

Dunno how you're going to cast the block tho. Casting that much steel is pretty hard for a backyard setup, I think. Maybe if you could cast it out of aluminum...
 

NDT

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You would have to add the two things that make a make a multifuel different from a diesel: the evaporation cup in the top of the piston and the injection stream, not mist, of fuel directed into the cup.
 

dozer1

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This is a related thread that I remembered posting to awhile back http://www.steelsoldiers.com/deuce-modification-hot-rodding/54647-modern-multifuel-redesign.html if someone wanted to check it out. This thread is not the same tho. I like the pre computer 5.9 as a starting point like oldman99 had pretty much figured out. Would make a good size engine that is capable of hauling some stuff in a mad max type of world. Also a super fuel efficient choice for basic transportation would be good as well. Like a VW Rabbit diesel type of thing converted to be a multi. (not exactly a good off the shelf choice there)

I dont know all of what it would take to convert 1 to a multi, but there is many ways to increase compression the ratio of an engine. Domed pistons, shaved heads, thinner head gaskets,even engine boring to name a few.
 

jesusgatos

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You would have to add the two things that make a make a multifuel different from a diesel: the evaporation cup in the top of the piston and the injection stream, not mist, of fuel directed into the cup.
That's how I understand it. Multifuel 12V 6BT would be pretty rad, but then the only thing you'd gain is the ability to burn gasoline and that's really not such a big deal if the whole point is being able to burn everything else.
 

wreckerman893

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Are you doing this execise with the idea of making an engine to drop in as a replacement for stock automotive engines or for a new multi-fuel powered vehicle?

While redesigning the wheel is a pastime of mine I think that it would be hard beat the old multifuels if you were putting them in a truck of comparitive size to the deuce.

Most old diesels can be ran on a mix of flammable liquids if you don't overdo it and mix them with regular diesel. Years ago a trucking company I worked for dumped used motor oil into the road tractors we ran long haul in....this was about the time fuel prices started moving upward.

As for gasoline engines I used to run an old lawn mower I had on mineral spirits mixed with gas....it smoked a lot but it got the grass cut.
 

pacebm

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Increasing compression is fairly easy............getting the engine to hold up under the higher pressures would be quite an engineering problem. Anything can be done with enough skill and money so I will be watching this thread with interest.
 

rchalmers3

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Re-engineering an existing compression ignition motor into a multi-fuel will probably require new heads, pistons, rods, IP, injectors and maybe a bottom end girder if the compression is significantly bumped.

In my opinion, duplicating even 1/2 the success and durability of the White/Continental/Hercules MF will take a lot of time and money.

Perhaps a project worth considering would be to purchase and collect the manufacturing tooling for the MF design so that production of engines and parts is available for decades to come. Then you would have a design that is proven to last a few laps around the block.

Rick
 

motomacguyver

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This is a very interesting thread. (Subscribed, hope I can add a little)

What I know from the Listeroid (slow speed diesel) forum is that mechanical, indirect injection is preferred. I think it has something to do with preheating the intake charge (the indirect injection part). That said, WMO or WVO also have to be preheated to about 250 deg. just to flow well enough to work.

I have read of the 12 valve (5.9?) Cummins and some older Mercedes Benz are working on WMO, WVO. Two fuel tanks are required, one for normal diesel and one for heated WVO, WMO. Once the engine is warmed up you can switch to waste oil. Then to cool down you switch to regular diesel. I would think if you have a setup that would run WMO, WVO you should be good to go with about any diesel like fuel mixture.2cents
 

QuickSilver

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As far as high compression goes, diesel performance enthusiasts, sled pullers, and drag racers use high compression 12v 6bt engines all the time, so I would think it would be a good candidate from that standpoint. The Bosch P7100 used on these engines is also nearly bulletproof, as well as capable of handling different types of fuel. A different piston design as well as a different injector design would probably be the only needed modifications.
 

Hammer

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There is more to it then that.
I have been thinking a LOT about this exact topic for quite some time now.
I figured two setups would be nice to have.
I would like to base one off of the GM 6.2 setup (indirect injection diesels already have a high compression ratio, stupid easy setup, and already have a low pressure setup for the injection.)
And a much smaller engine, like a small VW, or maybe older benz. Thinking here is that they would make EXCELLENT power plants for house hold sized generators.
Think of that, a 5k to 10k (or up to 30k really) that runs on ANYTHING!

The truly hard part is designing a new head. I don't know of ANY other head that is close enough to how our multi-fuel heads are in design.

If one doesn't know.
Stupid simple terms of how our multifuel engines work.
Fuel is SQUIRTED into the cup in the top of the piston. Note the cup even has a cut in it to help the fuel squirt in without atomizing any of the fuel, yet.
Second, and the hardest part, the head is designed so that all incoming air is swirling just right, so that when it enters the cylinder, it is swirling directly into the cup in the top of the piston. The swirling air is what atomizes the fuel, which is obviously a technical feat to do this close to top of the compression stroke.
The high compression ratio is required to ignite the fuel when it is being atomized in this form.
Newer diesels use higher fuel pressure, smaller holes in the injectors, etc. to help precisely atomize the fuel.

So, designing the pistons is easy. Copy what we already have. Then try and find an engine with a head design that closely matches that of our MFs as well.
Also, having an engine that already has a high compression ratio solves a lot of other issues.
 

QuickSilver

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Ok, I can see where the head design would be quite a trick. That sounds like it would involve machining a custom head, which is not cheap.
 

Westex

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Was not the original hypercycle design of the multifuel a German design, by the predecessor to the current MANN line of engines?
 

jesusgatos

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Regarding compression, what's the difference between the static compression ratio and the effect that a turbo has? With a turbo, I guess it's more in/out, but the compression ratio would still determine how much that air is compressed beyond whatever psi it's at when it enters the engine. Is that right?
 

Hammer

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Regarding compression, what's the difference between the static compression ratio and the effect that a turbo has? With a turbo, I guess it's more in/out, but the compression ratio would still determine how much that air is compressed beyond whatever psi it's at when it enters the engine. Is that right?
To a point, but you need the CR to be high to START the engine in the first place.

I think a newer MF would definitely benefit from forced induction. But I think that it should be able to run without it.
 
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