Vegetable Oil SVO WVO waste cooking oil as biofuel

[mike_belben]

i read sunwizard's cummins thread over and over for a year while collecting parts and trying to rationalize ways to reduce the components. over and over i was convinced to leave the setup alone. schematically, mine is identical with the exception of an added bleed port and a valve to isolate the grease side from the veggie side at the final tee, for the sake of troubleshooting. i dont believe you can design a simpler, cheaper or more dependable system than his. Big thanks to SW!

here is sunwizards schematic


this is mine, still works the same, but the schematic accounts for physical layout of the components within my 97 dodge 3500. i do not show coolant flow for simplicity, only fuel. intersecting lines are separate unless they meet at a dot. colors are more or less arbitrary to help distinguish each segment of tube/hose.



i arranged all of my 3 way valves in a single row. i used SeaSense brand valves for about $12 each. they have 4 positions and will spin 360 degrees, meaning only two positions work, and two dont. make sure you are very aware of how the handles are supposed to be BEFORE you mount them. buy all the same size so that you only need to keep a single spare in the tool box. there is only one stock 3/8 metal line in the truck, the rest are 5/16 and the 5/16 hose fits over all of them snug. 3/8 fuel hose will work but i recommend USA stainless double hose clamps on the pressure side. i used 30R7 fuel line.


valve connections


i sharpened the end of a thin plumbing pipe, heated it with a torch and hammered it into the carpet/insulation where valves and bolts needed to go through the floor. worked excellent.




the carpet is 3/4" thick with a heavy plastic mat


packed fiberglass around the valve stems to keep noise down


all 3 levers toward the tail lights = diesel. all 3 levers up = grease.


this is the space youve got to work with on the tranny tunnel. looking straight up from the ground. tight but adequate.


this is the .090" sheet that eventually became my 65 gallon L shaped veggie tank.




it was a LOT of tig welding


bored through my brass fittings.. .385" ID for .3/8 tubing.


heater loop







sits ontop my backrack rails, under the toolbox, and runs over to the stack.




coolant in, coolant out, veggie out, vent


sight tube


tank drain and tee for eventual expansion to underbody tank as well.



tube in hose




with stock diesel filter housing in place


without diesel filter housing


i cut my return line and removed the metal tubing to reroute with rubber hose in an easier access position, there are two fasteners on the tube.


pay close attention to the heater/strainer as it has 2 common failure methods


burned up heater element, sucking air at plug


check often, never know whats in there



gelled veggie


cut injector drain


double banjo bolt that needs to be sealed.


machined aluminum spacer installed



3/16 hose on the drain line


to a tee down by the tranny


return hose and nylon boost line to guage


my FPHE has been moved to the area above the exhaust manifold to make use of free heat. insulation and shielding will be added.



heated filter


1/2" rigid copper sweat fittings for tapping into coolant hot side. ball valve controls flow to heater core, bleed port is high point for getting air out. 5/8" heater hose fits perfectly.


1/2" rigid copper tee soldered to stock steel return line


fuel feed into injection pump




coolant returns from veggie loop back to hardpipe through copper sweat fittings


machine aluminum block serves as the Tee between veggie and diesel just before the injection pump, and has 1/8 npt ports for temp and pressure senders. ball valve is to isolate the two systems for troubleshooting, and the shraeder relieves air trapped here in the systems highest point.


remove valve core and use hose to bleed.. either with vaccuum pump, or by cranking from one tank then the other. works phenomenally well.


i primed with a vaccuum pump and clear hose into jugs of fresh diesel




jug on the left is what went in. on the right is what came out, one pass through brand new hoses and filter, i swear.


this jug came in very handy for filling the stock diesel filter without having to remove the canister from under all the lines.

[SunWizard]

Looks good. Be careful with all those hoses near the turbo and exhaust, they will quickly melt or harden and crack unless you add lots of shielding. Some of those pics must have been hard to get!

[mike_belben]

i just stuffed the camera under the brake master and took 20 pictures at a time, then narrowed down to the best. couldnt really see any of it by eye.


ill be slipping a second rubber hose cover ontop the grease line and insulating with self adhesive foam with silver foil backing from lowes. id have made it a hardline but changing the veggie and oil filters are much easier if you can lift the veggie filter head out of the coil and rest it off to the side.

[mike_belben]

drove it today, IR thermometer shows 180F on outside FPHE, and 165*F grease temps on gauge just before IP, was 30*F. i still have to insulate more lines, and fab a heat shroud to sit over the FPHE. i expected the coolant line into the tank to be just warm, but it almost burned me, 130*F without insulation.

still troubleshooting a fuel pressure issue, 99% sure its the overflow valve.

[mike_belben]

i put a new overflow valve, replaced the rotted rubber elbow from strainer to lift pump, ditched the leaking fuel heater and still had low pressure. it ended up being the lift pump, which was a carter brand and not the same as the cummins unit.. broken main spring inside.

went on a 2500mile roadtrip from mass to tennessee xmas --> new years, and a 300 mile trip yesterday. only issue seems to be on the suction side of the lift pump. in below 20F weather, on long climbs i can dip fuel pressure to nothing and start getting dead pedal. switching the tank valve (only) back to diesel INSTANTLY boosts fuel pressure back above 10psi even if i stay WOT,, or itll go to full pressure if i lift off. this response on the gauge is immediate, there is zero chance that the engine is drinking diesel because it would have to empty the filter and FPHE of veggie. the pressure is shooting up because its struggling to draw grease from the tank. once i added a few gallons of ULSD to the 60 gallons of veggie, the pressure came up a few psi and dead pedal was eliminated. down in tenn during 50+ weather, fuel pressure was fine on either fuel. i think the solution would be a bigger heated loop inside the veg tank, as mine is very minimal. my veg pickup tube might not even be close enough to the heater loop to have an effect.

other than that, its been great. saved me what i paid for it in the first trip.

[veggietruck]

Looks good. Be careful with all those hoses near the turbo and exhaust, they will quickly melt or harden and crack unless you add lots of shielding. Some of those pics must have been hard to get!

I will just say this....I have been running WVO in my 97 cummins for over 6 yrs now. this system is WAY TO COMPLICATED! all you need is one valve...that is if u just take the fuel return line back and tee it to the fuel pickup line ahead of your ONE VALVE.
This does many good things:
First...you stop manufacturing water in your tanks...you see when hot fuel hits cold fuel in a tank it instantly condensates. (my water has gone to ZERO!!
Second:....the fuel retuning from the motor is hot in just a few seconds, my truck idles for about 5 minutes then i switch tanks even if its 5 degrees!
Third....SAFETY!...less is better...all one needs is for a line rupyure under that hood to burst and buy buy truck...ever had a VO fire on hot manifolds?
My truck has over 500HP and will smoke most BMW's on this system
Oh and Forth: IT'S Cheaper to do!

[mike_belben]

how bout a schematic? what are your fuel temps on grease and on diesel?

[SunWizard]

I will just say this....I have been running WVO in my 97 cummins for over 6 yrs now. this system is WAY TO COMPLICATED! all you need is one valve...that is if u just take the fuel return line back and tee it to the fuel pickup line ahead of your ONE VALVE.
This does many good things:

That has many big drawbacks. Looped return all the time means a 20 minute purge instead of 20 seconds. Any air after a filter change is trapped and causes trouble. A shared filter is trouble too since if it clogs you are stuck instead of simply flipping a switch and continue on.

First...you stop manufacturing water in your tanks...you see when hot fuel hits cold fuel in a tank it instantly condensates. (my water has gone to ZERO!!

I don't understand how you are "manufacturing water", but with this design there isn't any WVO going back to the tank except for a few seconds at purge time.

Second:....the fuel retuning from the motor is hot in just a few seconds, my truck idles for about 5 minutes then i switch tanks even if its 5 degrees!

The fuel temp doesn't help heat the engine any quicker, so makes no difference to switch quicker. You still have to warm up the engine.

Third....SAFETY!...less is better...all one needs is for a line rupyure under that hood to burst and buy buy truck...ever had a VO fire on hot manifolds?

I agree, its best to keep all fuel lines away from the manifolds for safety.

Oh and Forth: IT'S Cheaper to do!

Yes but you lose money in the long run due to much more diesel burned during the 50x longer purge times.

[veggietruck]

I will just say this....I have been running WVO in my 97 cummins for over 6 yrs now. this system is WAY TO COMPLICATED! all you need is one valve...that is if u just take the fuel return line back and tee it to the fuel pickup line ahead of your ONE VALVE.
This does many good things:

That has many big drawbacks. Looped return all the time means a 20 minute purge instead of 20 seconds. Any air after a filter change is trapped and causes trouble. A shared filter is trouble too since if it clogs you are stuck instead of simply flipping a switch and continue on.

First...you stop manufacturing water in your tanks...you see when hot fuel hits cold fuel in a tank it instantly condensates. (my water has gone to ZERO!!

I don't understand how you are "manufacturing water", but with this design there isn't any WVO going back to the tank except for a few seconds at purge time.

Second:....the fuel retuning from the motor is hot in just a few seconds, my truck idles for about 5 minutes then i switch tanks even if its 5 degrees!

The fuel temp doesn't help heat the engine any quicker, so makes no difference to switch quicker. You still have to warm up the engine.

Third....SAFETY!...less is better...all one needs is for a line rupyure under that hood to burst and buy buy truck...ever had a VO fire on hot manifolds?

I agree, its best to keep all fuel lines away from the manifolds for safety.

Oh and Forth: IT'S Cheaper to do!

Yes but you lose money in the long run due to much more diesel burned during the 50x longer purge times.

where do you think the waters comes from in most diesel tanks, only a minute amount comes by way of the fuel station.
what happens is when the hot bypassed fuel from the motor mixes with cooler fuel in any tank condensation happens 100% of the time..that is how our rides manufacture water, and it is much worse in cold weather..thus gelling problems. (Many big rig drivers re-rout the return line to there filters now for that reason)

as far as purge time goes...i push fuel at 150 GPH and 60psi, with a P pumped cummins complete purge takes about one mile of driving at 35 mph...i know this because i only use one SS cleanable filter and have checked the filter in my driveway to see. (I have a 125 gal VO tank, and only use around 5-6 gals diesel per tank..aprox. every 1800-2000 miles)

and i have not changed a filter in 4 yrs since i went with the cleanable one.

Didn't mean to rub u the wrong way, but your system is far from simple.

one thing i forgot to mention is i do have a HOT FOX fuel pickup in my VO tank.

And i do agree with the other guys post...thats a lot of stuff around your turbo....keep a halon fire extinguisher handy.

[mike_belben]

eventually im going to move all of it over to the driver side area around the brake master cylinder. also going to run bigger lines.. 1/2" after the pump, 5/8 before it. had a lot of trouble with thick fatty grease this winter.. ive been putting a few gallons of diesel in my tank to thin it out but still have low fuel pressure sporatically. im just about certain its from fat blobs clogging the siphon tube but i dont want to add more heat to the tank and advance the poly. bigger tubes will solve the issue and ill have a very happy system. i found 3/4" 3 way valves, gonna put them much closer to the front and use push/pull rods.

im really happy with this system. its very dependable with a ton of adjustability and everything on it is only a few bucks to replace, not one expensive part. ive had the truck stall in traffic while working out my grease bugs and been able to switch back to diesel, crank and get moving again before the light changed. try that with a shared filter and a little gel.

[mike_belben]

another change im gonna make, instead of siphoning from the top, im gonna draw from slight off the bottom through my drain bung. like a standpipe sticking an inch into the tank. that'll cut out 4 feet of tubing and be assisted by the pressure head rather than require the pump to lift 30 inches.

[SunWizard]

where do you think the waters comes from in most diesel tanks, only a minute amount comes by way of the fuel station.
what happens is when the hot bypassed fuel from the motor mixes with cooler fuel in any tank condensation happens 100% of the time..that is how our rides manufacture water, and it is much worse in cold weather..thus gelling problems. (Many big rig drivers re-rout the return line to there filters now for that reason)

Water comes in mostly from humid air entering the tank as the fuel is consumed. That moist air can condense on a cold tank wall. Hot fuel returning would make less condensate since that requires a cold tank wall and its heating it up.

Water in the diesel tank isn't much of a problem since it separates naturally and is removed by the stock filter system, and you get a simple warning light that you need to hit the drain button on the bottom of the filter to fix it. I still have never gotten any water in the diesel filter in 5 years, and I haven't heard many complaints about it.

as far as purge time goes...i push fuel at 150 GPH and 60psi, with a P pumped cummins complete purge takes about one mile of driving at 35 mph...i know this because i only use one SS cleanable filter and have checked the filter in my driveway to see. (I have a 125 gal VO tank, and only use around 5-6 gals diesel per tank..aprox. every 1800-2000 miles)

150 gph is the rate at high rpm and stock full return to tank. With a looped system like you have, the diesel flow rate is limited to whats burned by the engine: 1 gph at 20mph or less (20mpg/20mph=1gph), like at idle where most purging is done. So at that rate, at the end of 20 minutes purge, you have added 1/3 gal. of diesel to dilute the ~1 gallon looping around in the filter, lines, and IP. That means you still have a 66% VO blend in those places after 20 minutes. Lucky the cummins is strong enough to start on blends but its not good in <20F weather and can't really be called a purge.

and i have not changed a filter in 4 yrs since i went with the cleanable one.

That's mainly because they don't filter much out, they have a bad micron rating, and can't hold much of even the large particles before plugging. Have you looked at its ratings compared to a stock filter?

[veggietruck]

where do you think the waters comes from in most diesel tanks, only a minute amount comes by way of the fuel station.
what happens is when the hot bypassed fuel from the motor mixes with cooler fuel in any tank condensation happens 100% of the time..that is how our rides manufacture water, and it is much worse in cold weather..thus gelling problems. (Many big rig drivers re-rout the return line to there filters now for that reason)

Water comes in mostly from humid air entering the tank as the fuel is consumed. That moist air can condense on a cold tank wall. Hot fuel returning would make less condensate since that requires a cold tank wall and its heating it up.

Water in the diesel tank isn't much of a problem since it separates naturally and is removed by the stock filter system, and you get a simple warning light that you need to hit the drain button on the bottom of the filter to fix it. I still have never gotten any water in the diesel filter in 5 years, and I haven't heard many complaints about it.

as far as purge time goes...i push fuel at 150 GPH and 60psi, with a P pumped cummins complete purge takes about one mile of driving at 35 mph...i know this because i only use one SS cleanable filter and have checked the filter in my driveway to see. (I have a 125 gal VO tank, and only use around 5-6 gals diesel per tank..aprox. every 1800-2000 miles)

150 gph is the rate at high rpm and stock full return to tank. With a looped system like you have, the diesel flow rate is limited to whats burned by the engine: 1 gph at 20mph or less (20mpg/20mph=1gph), like at idle where most purging is done. So at that rate, at the end of 20 minutes purge, you have added 1/3 gal. of diesel to dilute the ~1 gallon looping around in the filter, lines, and IP. That means you still have a 66% VO blend in those places after 20 minutes. Lucky the cummins is strong enough to start on blends but its not good in <20F weather and can't really be called a purge.

and i have not changed a filter in 4 yrs since i went with the cleanable one.

That's mainly because they don't filter much out, they have a bad micron rating, and can't hold much of even the large particles before plugging. Have you looked at its ratings compared to a stock filter?

my filter is 10 micron absolute...not nominal,(does not really matter i centrifuge to at least 5 micron) will not let anything larger than 10 pass..it does not bypass either, my filter has nearly 400 sq in. of filter area, and holds almost a gallon....yes it was pricey over $500.00 but worth every dollar..it has never gelded, it can't because i am pumping hot fuel into it from the fuel return line in fact when i get off the interstate it is very hot to touch.

[fivelessonslearned]

Great set up man, I have a quick question for you about the shraeder valve, as well as the ball valve you use to isolate the systems. You note that both are installed just before the injection pump at the highest point in the system, and I have to assume they are installed on the WVO line before it tees into the diesel line, right? And just out of curiosity, why not just install another three port valve switch instead of the tee if you want to isolate the systems, assuming it's possible to get a valve switch that has settings to allow for only WVO, only diesel, and both lines to be open simultaneously?

Also, you say that you "remove valve core" and use a hose to bleed the system. What do you mean by that? And any advice on what kind of hose that is you're attaching to the shraeder valve and where I could find it?

[mike_belben]

i used those parts because they are what i had on hand and i had to troubleshoot major fuel system issues that had accumulated from a bucnh of rotted hoses, leaking heater, etc. the schraeder wasnt part of the initial plan.

the hose was just a brake bleeder canister hose, nipple and can for bleeding that day. any auto parts store sells them.

ive since machined an aluminum block that is bolted to the IP via the feed port/banjo bolt. its got several passages, all with NPT threads and acts as a junction. diesel and grease each have their own port in the block that lead to the banjo bolt and into the pump. fuel pressure guage has the 3rd port, and the 4th is a bleeder outlet with a brass tee valve, the needle and seat style that typically are used to tap water lines for refrigerator ice makers and stuff. all i have to do is unscrew the needle seat and fuel goes to a permanently mounted catch can via pushlock hose. basically i can bleed the pump with no tools or mess, just open a valve and crank, it spits the air and fuel into a jug on the fenderwell.

close valve, fire up and go.