special V8 multifuel vehicle

[dustyfirewalker]

hey oil pan

i have thought about using coolant but im afraid i wont get the fuel and air entering the motor hot enough to vaporize heavier liquids, im pretty sure coolant would be perfect for alcohols and other lighter flammables, from what ive seen it looks like most of the old kero tractors and such had a section of intake manifold connected to exhaust, similar to a v8 cross over but bigger area and a sharp turn to ensure atomized fuel will hit the hot spot

i just found pics of those egr cooler heat exchangers those are neat, i also just the other day found diesel grid air intake heaters i believe for cummins that look very similar to what i was fabricating before,

the little experience i do have with heat exchangers (calculating fluid mass and q exchange in thermo, and building a fuel line pre heater with coolant), the one thing ive noticed is that the hot and cooler mediums mixing together usually dont ever reach the same temperature. for instance in my case with 700 deg f exhaust gas heating a 100-200 deg f air and fuel charge in a heat exchanger the exiting exhaust will be cooler, but the vapors routed to the engine wont hit 700, maybe more like 500, and with less than adequate surface area to transfer the heat the exchange is less effective, so temp will go down further, i havent taken heat transfer systems yet, so im not exactly sure how to go about finding the right surface area to transfer the heat trough a particular substance.

im hoping someone could point me in the right direction, alot of what ive found is just "maximize surface area for best heat transfer" but i dont have a whole lot of room in my engine bay

when i get some more down time (about to go work) ill post a sketch of how i plan to get fuel and air from the q jet to the exhaust area and back to the intake,


keep modding!

[oil pan 4]

Only the most largest and slowest flowing heat exchangers are any where near 100% efficient.
Diesel intake heaters and flammable materials do not go together, diesels with intake heaters have warning stickers stuck all over the inside of the hood warning not to use starting fluid.

I figured you also might want to pre warm some or all of the air with coolant before it reached the carb. I had to retype my post yesterday because of my lousy internet connection and forgot to retype the part about preheating the air with coolant.

[JRMichler]

Originally Posted by dustyfirewalker

i havent taken heat transfer systems yet, so im not exactly sure how to go about finding the right surface area to transfer the heat trough a particular substance.

im hoping someone could point me in the right direction, alot of what ive found is just "maximize surface area for best heat transfer" but i dont have a whole lot of room in my engine bay

I'll take a stab at calculating heat transfer area. Some assumptions:

Exhaust gas temperature 1500 deg F.
Exiting heated mixture temperature 700 deg F.
Counterflow heat exchanger.
Heat transferred 113 Kw.
Heat transfer coefficient 5 BTU/hr-ft2-deg F

Estimate average temperature difference between hot and cold side is 700 deg F. Then the heat transfer rate per square foot is 5 BTU/hr-ft2-deg F X 700 deg F = 3500 BTU/hr-ft2.

The total heat transfer rate is 113 Kw X 3412 BTU per KwH = 386,000 BTUH.

Then the heat exchanger area needed is 386,000 BTU/hr / 3500 BTU/hr-ft2 = 110 ft2. This seems large. If the real heat transfer rate is larger, the required area will be smaller.

Another source of error is the average temperature difference. I just made a SWAG. If you feel ambitious, calculate the heat capacity of exhaust gases resulting from 500 ACFM into the carburetor, then calculate a more correct average temperature difference.

[dustyfirewalker]

yeah 110 ft^2 is alot of surface area now that im looking into heat transfer coefficients im getting alot more relevant heat xchanger info.

one thing i think is weird, based on engineering tool box, Liquids and Fluids - Specific Heats

alot of hydrocarbons have a very close to equal specific heat, obviously there is some variance, but its very close to equal across the board

im going to run some more numbers, anyone else that wants to give it a stab feel free!

ill post some more sketches and numbers when im done thanks

[sarguy01]

Any updates?

I know this might be against the Bronco's purpose, but how about removing the added things, like the chains on the bumper, to help reduce aero drag? No matter the fuel that ends up running the Bronco, you'll end up using less of it if the Bronco is a little bit better aerodynamically.

Good work so far!

[dustyfirewalker]

hey thanks for the check in sarguy.

yeah the chains are heavy, I'm looking into HD tow straps, much lighter, and possibly synthetic winch line. I'm also thinking about the best soft top for reducing drag co. a tonno or something else...

my laptop touchpad just went out and I'm on a friends so ill be quick

i got the body lift done. lots of room in the engine bay, still planning on the multi fuel experiment, and looking at smokey yunicks ideas,





ill talk more about that later, i do have some pics of the stereo with the body lift and LED light bar installed. I'm going to fiberglass the wood with kevlar fiber mat then als liner them to match the truck. i have all my circuit breakers and solid state relays I'm about to lay out harnesses and start getting all the electrical done right.


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I've just been busy lately ill keep taking pics and get them up when i can

[sarguy01]

Are you planning on using a turbo?

In that second diagram, it looks as if gasoline would be the fuel, but it goes into the engine as a vapor rather than in droplets. So, the engine's hot coolant preheats it and it gets further heated via the non-intercooled turbo charger?

[dustyfirewalker]

i am considering the benefits of using a draw through turbo set up.
the q jet could just get a fat set of secondaries and that would be most of the carb tuning its has great partial throttle response right now.
i have wanted a heat exchanger and a rise to ensure vapor is whats being burned, hopefully the intense heating in the bottom ensures oils and various other flammable liquids are vaporized and then combusted.
i can just imagine what a 100k rpm turbine could do to a fuel air mixture.
because the turbo sucks on the carb, carb icing is possible, thats the coolant heat exchange and air preheat
the turbo sucking on the carb also means running a carbon seal on the compressor turbine.
in my intended uses i think i would be better suited with a fast spool up and max boost at 7-9 psi, while only ever using 5 max. a large waste gate is needed.
since I'm talking about a boosted engine with milled heads and zero decked block and trying to run god knows what i try to test in the fuel tank, i think a water injection kit with variable boost and exhaust gas temp / wideband O2 is needed.
smokey said he could run 87 octane, i figure since i don't know if he was running a low CR or his camshaft selection,thats why I'm planning on water injection.

I'm still weighing all the possibilities. worst case i wind up with a e85/pumpgas 400-500 horses and same/worse mpg. I'm really shooting for ensuring anything the carb spits into the intake will be a flammable vapor. so I'm looking at compressor maps and price quoting the whole deal. water injection with heavy oil fuels reminds me of articles about the old rumely oil pull tractor engines. its been done with kerosene and tvo

again my computer is still broke, I'm going to work on the truck all day tmrw so might have some better pics.


anybody know the best shape for a soft top on a bronco? i imagine it looks similar to what one people here have done to pickups..

take it easy

[dustyfirewalker]

so i got a new computer, and then before i got my pics off my phone it got soaked in water :/ so i have made a lot of progress(but no pics right now), and have a few buddies helping me now.

this is where the project is headed:

im building a smoky yunick inspired intake and exhaust system. (im convinced thats what it takes to get usable power from low octane fuel substitutes, oils, and mixers like ive been describing in this thread) it will involve a draw through turbo, and it will use two heat exhangers (coolant and exhaust) my nice q jet, and water injection. i have a 9.5 gal tank for the water/methanol injection to match my 27 gal of fuel capacity. ontop of water injection i have the coldest set of plugs autolite sells, a wideband O2 sensor, "LilKnock Meter" , and i will be locking out my distributor since ill be seeing boost.

ive been looking at compressor maps, and i have a few turbos im thinking about, i would like to see a max of 10 psi boost, i have been using the compressor maps as they are intended, but im wondering...
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since a turbo map has a pressure ratio on the Y axis and a volume/mass flow rate on the X axis, does a draw through turbo set up cause the pressure ratio to sky rocket? there is a vacuum on the inlet of the turbo so the pressure ratio isnt on the map, right?


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i have all my other numbers calculated, i would like to flow between 42 and 50 pounds of air max throttle. thats what the formula says at least. but i cant decide if my pressure ratio numbers are correct since there will be a vacuum on the inlet side of the turbo in this configuration

anyways, thats all thats holding me back from choosing my turbo, i have a bunch of nice copper, aluminium, steel, and stainless steel to fabricate my "experimental smoky yunick inspired fuel system. i also have a whole other 460 efi engine to build this on for the perfect fit, and as soon as i get the rest of my parts i will build it.


i have tested out my stereo, it needs the speaker panels to be coated with bedliner. this bronco BUMPS!

i have a wicked ARB onboard air set up im installing they boast 3cfm at 90 psi, (air tools) my rear bumper will be the air tank and my numbers say 4 gal of air capacity.

im looking for a massive power inverter, i would like to be able to have 30 amp service 120v ac on the truck.

im replacing my spool in my 10.25 rear end with a posi, and adding a traction bar, it already has new tires and bearings and disck brakes.

i bumped my AC condenser and the line broke, so i have looked into how to get a "high performance " air conditioning system. i will be using all new lines and compressor, along with a R134A condenser (for maximum surface area) and the ford red orifice tube (smallest orifice available) this with R12 as the charge should give ice cold air anytime

i have been doing a TON of wiring. the dash is about to go in and final connections will make everything work!


anyways, ill have some pics soon ttyl

[H-Man]

I'd run R134A unless the system started life as an R12 system because R12 systems seem to a PITA to keep running (around here at least) due to the fact that almost anyone that will spend money on AC has a car running R134a and thus almost nobody carries anything for R12 systems.
I manage cold air in my prizm (air coming out of the vents is 90-100F colder than the condenser so when sitting it ends up being 60F below the outside air temperature and it only stops there because the compressor cycles off) and it is a very crude R134A system (they barely changed the design from the R12 system, I'm not even sure if my condenser has a higher FPI.)