1993 1st Gen Cummins - Dual Pump Conversion

For discussing the modifications needed for diesel vehicles to run with 2 tank veggie oil conversions.

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1993 1st Gen Cummins - Dual Pump Conversion

Postby sinthome » Tue Oct 01, 2013 1:11 pm

Hi folks. I have been obsessing over a diagram for my DIY conversion and am weighing my options. Here are the things I am pretty set on:
I want to use separate lift pumps for D2 and VO, I am hoping a Walbro FRB-5 is a good choice.
I have a 65 gal aluminum toolbox tank.
At first I was leaning toward a TIH design with a separate, unheated VO return line. But I am worried about stress on the tubing when bombing down a rutted gravel road loaded down with logs. Even unloaded, I can see the play in my truckbed, shaking around 1-2" in relation to the cab. I don't see how aluminum fuel line could last on that setup. Is my bed just really loose or am I missing something?
The major advantage that I see to TIH is that VO can cool in the supply line and will still get reheated while warming up without having to recirculate it. Foregoing TIH seems to necessitate back-flushing all the VO out of the unheated length of fuel line before letting the truck sit overnight. So, after abandoning TIH, I began considering a single VO supply line that would get fully back-flushed with D2 during the purge. But then I read that back-flushing through the VO filter can damage it and is generally not a good idea. Now I am stumped with how to go about redesigning a system that utilizes a single fuel line to/from the VO tank, does not contaminate the stock fuel lines, fully purges the VO out of the supply line all the way up to the IP, but does not back-flush the VO filter. My last attempt removes the third 3-way valve and adds two check valves.. but I am starting to suspect there is a better way and that brings me here. At this juncture, I am hoping that you can either convince me that I can make TIH safe for my rig or re-route my proposed purge cycle for my specific design parameters. Or, just for fun, both!
Here are my diagram attempts-- first the TIH, then the back-flush single supply line, then the single supply with check valves for D2 purge without back-flushing:
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Any advice or links to other diagrams would be greatly appreciated. I am not trying to reinvent the wheel, but I do want to make the best choices on my conversion. Thanks! :D
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Re: 1993 1st Gen Cummins - Dual Pump Conversion

Postby SunWizard » Tue Oct 01, 2013 2:05 pm

Mine uses TiH and yes the bed shakes around 2" since I live on a rough 4wd road it gets it 2 miles of rough per day at least. Its been good for 7 years. The fuel lines are on the frame rail and don't get twisted, just a small flex on a 2' long curved section where it turns up to the tank. The trick is to make sure it doesn't rub anywhere.

My diagram meets what you are asking, and even though mine is a later model, the same diagram should work. But it uses 1 pump because there is no electric pump that even comes close to the stock one on 94-98 cummins. It could easily be changed to add another pump, but electric pumps are trouble for nearly everyone at some point, even with the expensive ones, so carry a spare. There are kits to convert your 93 to the piston pump used from 94-98, thats by far the best option.

See my diagram and full description in the converted vehicles section.
YVORMV - Your veg. oil results may vary.
95 Dodge Cummins 4x4 SVO WVO conversion.
81 Mercedes 300D- stock and happy on V80/D20 blend.
Low fossil net zero house- 100% solar power and heat.
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Re: 1993 1st Gen Cummins - Dual Pump Conversion

Postby sinthome » Tue Oct 01, 2013 3:34 pm

Awesome, thanks for the reply! I had looked at retrofitting to the 2nd gen pump, but I was hesitant since the one tutorial I found involved taking an angle grinder at the engine block.. can you point me to an adapter kit/pump source? Ok.. I am back on board with the TIH.. cheers!
sinthome
 
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Re: 1993 1st Gen Cummins - Dual Pump Conversion

Postby SunWizard » Tue Oct 01, 2013 5:59 pm

Here are complete instructions with part#s and pictures:
http://www.dieseltruckresource.com/dev/ ... ml?t=93722
No grinder to the block but you have to cut the insulation layer above the pump, which looks easy. It is a hard to get at spot unless you put it on a lift.

Even staying with your old mechanical pump is probably better than any electric pump, since they all have trouble with thick WVO.
YVORMV - Your veg. oil results may vary.
95 Dodge Cummins 4x4 SVO WVO conversion.
81 Mercedes 300D- stock and happy on V80/D20 blend.
Low fossil net zero house- 100% solar power and heat.
SunWizard
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Re: 1993 1st Gen Cummins - Dual Pump Conversion

Postby sinthome » Thu Oct 03, 2013 10:27 am

Hmm.. one advantage to the electric pump is that if it fails you can still switch over to diesel and drive home. I might try my luck with a Walbro FRB-5 mounted back in the toolbox section of my tank. It doesn't have to push that much for the 1st gens and then I get pump redundancy and the engine stays closer to stock. I have read that you need to remove the filter screen and the rubber gasket tends to get brittle and fail, but once that is switched to viton they stay solid for a long time.
sinthome
 
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Re: 1993 1st Gen Cummins - Dual Pump Conversion

Postby SunWizard » Thu Oct 03, 2013 11:29 am

sinthome wrote:Hmm.. one advantage to the electric pump is that if it fails you can still switch over to diesel and drive home. I might try my luck with a Walbro FRB-5 mounted back in the toolbox section of my tank. It doesn't have to push that much for the 1st gens and then I get pump redundancy and the engine stays closer to stock.

Its not really an advantage, not failing is always better than failing with a spare. Its not IF it fails its WHEN on electrics. The piston pumps don't fail much, so no redundancy needed, they slowly after 150k miles put out less pressure over a long time. Closest to stock is the stock mechanical pump.
YVORMV - Your veg. oil results may vary.
95 Dodge Cummins 4x4 SVO WVO conversion.
81 Mercedes 300D- stock and happy on V80/D20 blend.
Low fossil net zero house- 100% solar power and heat.
SunWizard
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Re: 1993 1st Gen Cummins - Dual Pump Conversion

Postby sinthome » Thu Oct 03, 2013 12:43 pm

Hmm.. well I did some price checking, looks like I can get the low pressure 2nd gen pump for $110 and the fuel line and fittings for another $80. Not bad. I need to go back and look at your thread again, I can't how you spliced the fuel line coming from the fuel pump. Would it be best to get the stock fuel line fitting or save that money to invest in a braided SS hose with aluminum fittings?
sinthome
 
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Re: 1993 1st Gen Cummins - Dual Pump Conversion

Postby SunWizard » Thu Oct 03, 2013 1:01 pm

sinthome wrote:Would it be best to get the stock fuel line fitting or save that money to invest in a braided SS hose with aluminum fittings?

Yes, braided is better since I just cut the stock line about halfway up to the filter. And that might make it so you don't have to trim the insulation above the pump to make it fit.
YVORMV - Your veg. oil results may vary.
95 Dodge Cummins 4x4 SVO WVO conversion.
81 Mercedes 300D- stock and happy on V80/D20 blend.
Low fossil net zero house- 100% solar power and heat.
SunWizard
Site Admin
 
Posts: 1723
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Location: N. Colorado

Re: 1993 1st Gen Cummins - Dual Pump Conversion

Postby sinthome » Tue Oct 08, 2013 5:11 pm

My 12V also has what I think is the factory optional transmission cooler installed. This runs coolant all the way back to a second radiator that is mounted in front of the driver's side rear wheel. Any advice on how this will complicate my coolant routing? It might only open up with a high temp switch, but I have no idea.
sinthome
 
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Re: 1993 1st Gen Cummins - Dual Pump Conversion

Postby SunWizard » Tue Oct 08, 2013 5:18 pm

sinthome wrote:My 12V also has what I think is the factory optional transmission cooler installed. This runs coolant all the way back to a second radiator that is mounted in front of the driver's side rear wheel. Any advice on how this will complicate my coolant routing? It might only open up with a high temp switch, but I have no idea.

A tranny cooler should only run tranny fluid to it for cooling, so I don't know what you have. My tranny cooler is up front of the radiator, and has no coolant in it. It shouldn't complicate anything since you want to tap into the cab heater lines only.
YVORMV - Your veg. oil results may vary.
95 Dodge Cummins 4x4 SVO WVO conversion.
81 Mercedes 300D- stock and happy on V80/D20 blend.
Low fossil net zero house- 100% solar power and heat.
SunWizard
Site Admin
 
Posts: 1723
Joined: Mon Dec 11, 2006 2:53 pm
Location: N. Colorado

Re: 1993 1st Gen Cummins - Dual Pump Conversion

Postby sinthome » Thu Oct 17, 2013 4:27 pm

Hmm.. I don't know what it is cooling back there, but I swear there is an auxiliary radiator doing something in front of the driver's rear wheel. I will have to investigate some more..

In other news I went for a low pressure version of the 2nd gen piston lift pump and now my fuel routing will look exactly like yours, Sun, with the exception of using solenoid valves.. I think.. unless you convince me not to do that too, lol.

A few more questions! Are the fuel inlet/outlet ports on this lift pump metric? I am trying to piece together all my hoses and fittings, now. I am trying to figure how much it'll set me back to go with Earl's Auto-flex and swivel JIC fittings after the pump. Might be worth it. Before the pump I will have the tank switch (solenoid). Can I run the TIH under the truck and up into the engine bay and straight to the valve (with the proper compression to NPT or whatever)? Or is that too many bends in the aluminum fuel line?
The last thing I really need to figure out is the wiring diagram and how to wire up temp sensor to 160F switch, delay timer, LED indicator panel and on/off switches. Any good tutorials on these tricky bits? Not rocket science, but a tutorial would be amazing.
sinthome
 
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Re: 1993 1st Gen Cummins - Dual Pump Conversion

Postby SunWizard » Thu Oct 17, 2013 8:51 pm

sinthome wrote:Are the fuel inlet/outlet ports on this lift pump metric?

I don't know since I cut the existing steel pipe.
I am trying to piece together all my hoses and fittings, now. I am trying to figure how much it'll set me back to go with Earl's Auto-flex and swivel JIC fittings after the pump. Might be worth it. Before the pump I will have the tank switch (solenoid). Can I run the TIH under the truck and up into the engine bay and straight to the valve (with the proper compression to NPT or whatever)? Or is that too many bends in the aluminum fuel line?

No problem as long as the bends are long radius, >6".
The last thing I really need to figure out is the wiring diagram and how to wire up temp sensor to 160F switch, delay timer, LED indicator panel and on/off switches. Any good tutorials on these tricky bits? Not rocket science, but a tutorial would be amazing.

I don't know.
YVORMV - Your veg. oil results may vary.
95 Dodge Cummins 4x4 SVO WVO conversion.
81 Mercedes 300D- stock and happy on V80/D20 blend.
Low fossil net zero house- 100% solar power and heat.
SunWizard
Site Admin
 
Posts: 1723
Joined: Mon Dec 11, 2006 2:53 pm
Location: N. Colorado

Re: 1993 1st Gen Cummins - Dual Pump Conversion

Postby sinthome » Fri Oct 18, 2013 7:49 am

Ok, thanks. I will just have to do more research!

Do you think I will have pulsing issues with a piston lift pump that delivers approx 12psi?
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