Cummins conversion: comments please

A description and pics of your SVO WVO Vegetable Oil conversion, help the next person who gets that model.

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Cummins conversion: comments please

Postby liquid solar » Wed May 29, 2013 5:36 pm

I finally found a clean 98.5 12 valve and she is ready for grease. Been studying Sun's schematic and pouring over the related links. I have a good feel for the design and would love to install Sun Wizards but time is scarce and considering a Greasecar kit that will simplify system install. System must be functional at -20F. I do realize it will cost more..but sometimes you got pay to play.

My possible mods to the greasecar system based on Sun's include: 1) adding a FPHE with ball valves to control flow to heater core and FPHE; 2) adding a ball valve to the coolant supply to tank to control how much heat goes to tank - especially in summer; 3) probably go with the electric valves but manual switches (keep it simple) (GC has option for both).

It seems the attached schematic shares a lot with Sun's with the following exceptions: 1) different entry point for veg return; 2) two valves instead of three; 3) somewhat different plumbing of veg probably due to the use of 2 valves.

First question: any big downsides to the Greasecar approach as outlined? It seems to have the looped return and VEG bypasses the diesel filter and uses the lift pump.
Second question: any additional mods suggested?
Third question: Vacuum vs pressure gage. If I had to go with one, which is better for system monitoring?
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Thanks!
liquid solar
 
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Re: Cummins conversion: comments please

Postby SunWizard » Thu May 30, 2013 8:47 pm

Hi and welcome to the forum. Good to see you got a great truck and are doing research before converting.
liquid solar wrote:First question: any big downsides to the Greasecar approach as outlined? It seems to have the looped return and VEG bypasses the diesel filter and uses the lift pump.

The big downside is the filters and more connections will be under vacuum. This can lead to air leaks which is a very common problem, and is very hard to track down. You also need 2 different filters that are designed to handle vacuum, and the stock diesel filter is not good for vacuum. It also means your filters will need changed more often since the max. vacuum that the pump can pull (-12 psi) is far less than what the strong stock lift pump can push (50 psi pressure.) Hoses can collapse with that much vacuum so you would need to use more expensive and more rigid hoses.
Second question: any additional mods suggested?

No but #1 is a big one.
Third question: Vacuum vs pressure gage. If I had to go with one, which is better for system monitoring?

Pressure is better for my plumbing since it lets you know if the lift pump is good, if the filters are starting to clog, or if there are air leaks. With your proposed plumbing, pressure may still be best if you put it after the lift pump, but I dont know since I never tried that plumbing.
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: Cummins conversion: comments please

Postby liquid solar » Fri May 31, 2013 10:47 am

Thanks Sun for the reply. That helps my understanding a lot. In view of that info I am considering doing your type of system just need to find a 30 or 40g tank.

I thought your tank was steel, then I followed the link and realized it is aluminum. Question on steel tanks (I have found more options with steel): It seems polymerization would not be an issue as long as I heated it gently and not at all in summer months.

For what it is worth I have a greasecar tank with copper heat exchanger in 2003 jetta TDI and poly has not been an issue (over 40k VEG miles).
liquid solar
 
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Re: Seasense valves

Postby liquid solar » Thu Jun 20, 2013 8:28 am

I am ordering parts for the SunWizard 2-tank, 3-valve conversion on my 98 dodge 12 valve.

Issue: I ordered 4 (1 extra) Seasense 1/4" 3-way valves as per SunW parts list and 3 of them were defective, and of dubious quality given that they have an important job in this conversion. Anyone know of a more robust manual valve? One option seems to be a standard plumbing type 1/2" brass three-way ball valve (threaded or sweat) but they lack the long axis/extension on the handle and may not work. Thoughts anyone?
liquid solar
 
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Re: Cummins conversion: comments please

Postby SunWizard » Thu Jun 20, 2013 9:06 am

Quality must have gone downhill on those. Mine have been fine for 7 years of tough use. What was the problem with 3 of your 4?
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: valves

Postby liquid solar » Thu Jun 20, 2013 11:25 am

The connection between the handle and internal plastic "ball" is flimsy and loose. That is, you turn the handle and the ported ball does not respond. So I am looking for a standard 1/2 ball valve (3way) and hoping I can mount that where you advised and still have the handle accessible. If you have any better ideas that would be appreciated.
liquid solar
 
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Pre-LiftPump Diesel Heater

Postby liquid solar » Tue Jun 25, 2013 5:10 pm

SunW, did you bypass/delete your diesel heater upstream of your Lift Pump? It is not shown on your schematic. I saw some pics on M Belbins conversion (97 dodge 12v, modded SunW 2 tank) where the filter was clogged with gelled WVO. I know some folks remove it (it or at least the heater part)but I am hesitant to remove it because I live in Montana and will be using rig all winter. Thanks
liquid solar
 
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Re: Pre-LiftPump Diesel Heater

Postby SunWizard » Tue Jun 25, 2013 5:26 pm

liquid solar wrote:SunW, did you bypass/delete your diesel heater upstream of your Lift Pump?

I kept that stock and it has been fine.
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


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