Propane conversion

[Bonaro]

Russ, these are the good 3M UV stable ties and they will hold up for years. I try to not use the automotive style screw clamps as I have been lacerated by them too many times. I use zip ties on fuel lines and other low pressure stuff and turbo clamps (hose clamps with a bolt not a screw) everywhere else. Any hose clamps remaining get folded over or wrapped in tape.

I am not done, I still need to make a manifold to be able to run off of the disposable tanks since I am able to refill those myself.

John, this weekend I plan to go over to a friends house and pump the water around in his above ground pool for a few hours. I will do some performance tests and report back

[Hoser John]

Great ,if you can hook up a jet and hose to simulate a dredging scenario that would be cool. We floated a 8" complete dredge in my buds above ground pool and sure was glad we did as needed some tweaks. Lotza luck on your tests-John

[Bonaro]

Yes, I plan on hooking up the jet. I need to simulate a full load on the motor so I can make the high end fuel adjustment.
I will try to have the disposable tank manifold ready so I can get a run time from a measurable amount.
Propane has about 10% less BTU than gas by volume so the run time should be very similar to gas

[Bonaro]

Yes, I plan on hooking up the jet. I need to simulate a full load on the motor so I can make the high end fuel adjustment.
I will try to have the disposable tank manifold ready so I can get a run time from a measurable amount.
Propane has about 10% less BTU than gas by volume so the run time should be very similar to gas

[Bonaro]

UPDATE:
I ran my test trials this last weekend and all went well. I started out in typical fashion by completely forgetting to load my foot valve
Fortunately I was able to prime the pump anyway.
I hooked up my 2 (new) disposable bottles and the manifold I built.

IMG_1976 (Small).JPG (59.28 KiB) Viewed 5004 times

I ran with this setup because it was a measured amount of fuel and I plan to use this as a backup fuel source so I needed to know if it would work.
I started up and amazingly I was able to prime the pump on the first try.
I ran the motor up to full throttle. On Gasoline the motor is at 3800 rpm under full load at full throttle. On propane I was able to reach 3500 rpm due to the lower amount of BTU's available in propane fuel. A simple adjustment of the governor and I was again able to hit 3800 RPM. I then adjusted the fueling block. This is a simple valve that limits the max amount of fuel that can delivered to the motor under full load.
Then I throttled down to 2500 RPM which is my normal dredging speed and started the timer.

20141207_135907 (Small).jpg (108.61 KiB) Viewed 5004 times

20141207_135956 (Small).jpg (107.56 KiB) Viewed 5004 times

After about 10 minutes I noticed some pretty significant icing on the bottles. I expected this because of the high rate of fuel flow and also because it was 40 degrees outside and about 85% humidity. I figured a quick solution that worked well.

20141207_141138 (Small).jpg (80.47 KiB) Viewed 5004 times

20141207_141259 (Small).jpg (91.32 KiB) Viewed 5004 times

I ran at 2500 for about a hour and 10 minutes when the tanks started going empty. I feel this is a pretty good run time on such small tanks. Each tank holds 16.4 oz. by weight, not sure what that translated into in volume but the original gas tank was 6 quarts and lasted about 3.5-4 hours.
The bonus was that I ended up with ice for a my beverages

20141207_145321 (Small).jpg (93.84 KiB) Viewed 5004 times

I then ran on the larger 20 pound bottle and all went well. I call it a complete success.

I am sold on this. The pros far outweigh the cons.

[Bonaro]

Well, the pics got all mixed up...late...fix it tomorrow

[AuTSaurus]

Looks great, Dan, good job! Are you also planning on using the larger propane tank/s, like the "turn ins" from Home Depot, or Lowes, or do you think they will be too heavy?

Greg

[russau]

yep good report Dan!

[Hoser John]

Cool science in action is so much fun. Looks like next spring will be a different experience dredging. Thanx for all the time on pics-John

[Bonaro]

I will use a standard 20 pound (5 gallon) portable tank. I have not done the math but I figure I can run 6 hours a day for 4 days on one tank. It weighs a little more but since its a 5" dredge it will easily support the weight. It will be nice to not have to pack all those little red cans around.