propane injection for a diesel

Biodiesel, Dual Fuel (Diesel/Propane, Diesel/NG), HCCI
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pud
Posts: 28
Joined: Thu Aug 03, 2006 4:11 am
Location: Quesnel BC Canada

propane injection for a diesel

Post by pud »

thought I would post this here as it is more propane related.
Ive been looking into propane injection systems, but theres no way Im shelling out $800cdn when I can buy a complete kit to run an engine on propane for a couple hundred here. Im planning on doing this to an old IDI non-turbo 7.3L. They flow 450cfm at 3500rpm, and 385cfm @ 3000rpm which is all the engine would really see....so what I am thinking here is picking up a kit that has an impco 425 and plugging that into the intake tract, and really leaning it out. I only need like 5cfm of fuel, so my question is can I lean it out to that extent? How?
1996 F350 Powerstroke, Crew Cab shortbox, 5speed -DD-
1990 F150 Extended Cab, shortbox, 5.0L 5speed "Project: Bronco Fund"
1990 Bronco 5.0L, 5speed "Project: Roadworthy"

franz
Posts: 1205
Joined: Thu Oct 07, 2004 7:57 pm
Location: Central Texas
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425 suggestion

Post by franz »

I would take the 425 as you describe and install a model J vaporizer for fuel. You wont need much, no need for the E or L. Play around with the spring in the J secondary (make it MUCH stiffer) so it wont begin to flow fuel until there is a high vacuum demand. I cant tell you how much to stretch it, you're on your own here.

As a guide, install the 425 and measure the vacuum at the fuel inlet (plug it and install a vacuum fitting). The engine should be at the rpm you want (ignore load since the diesel is open throttle anyway). The vaporizer should just begin to open here at that vacuum signal. There is probably some math you can do, the square inches of area of the diaphragm, the at load tension of the spring, the vacuum present in inches of water column, etc.

Franz

pud
Posts: 28
Joined: Thu Aug 03, 2006 4:11 am
Location: Quesnel BC Canada

Post by pud »

conveniently I was over at a friends place yesterday and he is building an F250 for his brother in law. It has the n/a 7.3L diesel in it, and he has 2 full propane kits. Ill figure out what pieces he has, regarding the mixers and vaporizers and post back probably tomorow. Sounds promising tho
1996 F350 Powerstroke, Crew Cab shortbox, 5speed -DD-
1990 F150 Extended Cab, shortbox, 5.0L 5speed "Project: Bronco Fund"
1990 Bronco 5.0L, 5speed "Project: Roadworthy"

C3H8
Posts: 1129
Joined: Fri Sep 09, 2005 11:23 pm
Location: Winnipeg, Canada

7.3 diesel

Post by C3H8 »

We spent quite a bit of time trying to add propane to a NA 7.3. In our case we were not successful at all. Adding even the smallest amount of LPG would actually reduce the power and increased the smoke. With a NA diesel the LPG just displaces the air. Since there is no turbo the volume of air cannot be increased in comparison to the fuel being added. Our results were very unexpected as we felt we would get some improvement in combustion but the opposite was true. You may have similar or better results. If you pursue the project please post your results.

pud
Posts: 28
Joined: Thu Aug 03, 2006 4:11 am
Location: Quesnel BC Canada

Post by pud »

this guy did it on his IDI http://www.members.shaw.ca/k2pilot/Propane article.html says it worked well for him. What kind of set up did you try? Did you try messing with the Injection Pump fuel screw to test differnet mixtures?
1996 F350 Powerstroke, Crew Cab shortbox, 5speed -DD-
1990 F150 Extended Cab, shortbox, 5.0L 5speed "Project: Bronco Fund"
1990 Bronco 5.0L, 5speed "Project: Roadworthy"

C3H8
Posts: 1129
Joined: Fri Sep 09, 2005 11:23 pm
Location: Winnipeg, Canada

LPG diesel

Post by C3H8 »

I can't answer all your questions accurately. The tech performing the work attempted this several years ago. We had done a substantial amount of work on turbo diesels using CNG as a replacement product. We had also done several performance models using core equipment (IMPCO products) and injectors with good success. The 7.3 was just a trial the tech was attempting on a relatives truck. As far as I know he tried different mixers including venturrri style mixers and carried out adjustments to the pump. He wasn't happy with the results and gave it up. We did not have a large enough market to pursue it further based on the return. This doesn't mean it can't be done just that we didn't see enough return in it to spend any more time on NA. The highest number of requests were for turbo's.

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