DUROPOWER 3500ES UPDATE!
I have "frozen" the design of my DuroPower 3500ES LPG/remote start conversion.
Here's the goals I started with:
1) LPG conversion
2) Remote start conversion
3) Suitable for a receiver hitch mount on my fifth wheel, keeping unit potentially able to remove easily and install on a new trailer should I trade in the future
4) Maintain a compact, quiet design that does not require setting up any additional/external sound enclosure
Since I was trying to keep as much of the regulator, muffler, solenoid, etc., "on board" and enclosed, I intially abandoned the Professor's GM trunk solenoid/primer design as it made the regulator difficult to fit in a confined space. I elected to try a bypass solenoid primer that is apparently commonly used with LPG zero-demand regulators. After much angst trying to get reliable starting without misfiring, etc., I gave up and mounted the regulator in the vertical plane, but rotated 90 degrees and went back to the Professor's
trunk solenoid! This gives reliable starting (a dead cold engine usually starts on the second cranking cycle attempt, a warm engine starts on the first cranking cycle) and the engine runs smoothly without misfiring.
Here's what the internals look like now:
This picture shows the regulator mounted vertically and rotated 90 degrees. The GM trunk solenoid is on the extreme right and activates the horizontal lever that depresses the primer button on the regulator. The blue box will be a junction box to bring in the +12v from the FW to power the remote start, the starter, the cut-off solenoid, and the supplementary fan.
Here's another view:
This shows from left-to-right: the primer solenoid, the cut-off solenoid attached to the regulator, the feed block, and the Beam micro-vac switch. You can barely see it, but the adjustable temp switch to activate the supplementary fan is mounted on the cylinder just below the feed block.
Looking the other way:
The "mailbox" looking thing is an insulated enclosure for the muffler. I initially wrapped the header, muffler and exhaust with header wrap, then decided to insulate and enclose the whole thing for further heat reduction. The disconnected wires seen go to the supplementary cooling fan in the "lid". The fan is a 500 cfm that hangs down from the lid to suck hot stagnant air from the genset - the bottom of the unit is totally open as originally designed. You can also see the 1/4" Hardiebacker panels that are attached to the foam-lined metal enclosure panels that originally came on the DuroPower. I glued them to the foam lining with 3M 377 adhesive - this lets them "float" and seems to help with sound abatement. The black umbilical in the center of the picture is the harness going to the waterproof remote start box on the other side of the panel.
One more shot externally:
This shows the open remote start box and the genset's control panel. I intend to eventually put a water-resistant cover over the control panel, so I ditched the key-start switch since it protruded too far out of the panel. I replaced it with a heavy-duty push-to-start switch and a separate "on/off" switch. It is wired so that a low oil level, loss of vacuum (engine died), manual select of the "off" switch or a button on the remote will break the ground to the cut-off solenoid and stop the LPG supply to the engine. The 30A outlet was not a "RV" outlet, so I pulled out that outlet and wired a RV pigtail (you can see it hanging from the bottom of the genset - this is temporary - I intended to eventually wire the 30A circuit into the FW with an automatic transfer switch). I took the duplex 20A outlet and put a single 20A outlet (the white outlet on the panel) where the 30A used to be. I'll probably mount a digital thermometer where the duplex outlet is blanked off. One other detail - I added the aluminum angle end pieces to the metal panels. The enclosure metal is thin and if you over-tighten a mounting bolt, it bends the edge of the panel. The angle reinforces the edge of the panel and distributes the pressure evenly. I also lined the inside edges with foam gasketing both to allow more even sealing pressure and also cut down a little more on sound abatement.
I still have to fashion a "lid" to divert water and form a duct for the cooling fan - hopefully, I'll get that done soon. Then all I have to do is bolt it to the FW's mount, connect the +12v, and if time permits, extend the FW's LPG piping so I'll have a quick-connect on the rear of the FW to plug the genset into. For now, I have a regulator with a quick-connect on a 20 lb bottle.
Regards,
John
I have "frozen" the design of my DuroPower 3500ES LPG/remote start conversion.
Here's the goals I started with:
1) LPG conversion
2) Remote start conversion
3) Suitable for a receiver hitch mount on my fifth wheel, keeping unit potentially able to remove easily and install on a new trailer should I trade in the future
4) Maintain a compact, quiet design that does not require setting up any additional/external sound enclosure
Since I was trying to keep as much of the regulator, muffler, solenoid, etc., "on board" and enclosed, I intially abandoned the Professor's GM trunk solenoid/primer design as it made the regulator difficult to fit in a confined space. I elected to try a bypass solenoid primer that is apparently commonly used with LPG zero-demand regulators. After much angst trying to get reliable starting without misfiring, etc., I gave up and mounted the regulator in the vertical plane, but rotated 90 degrees and went back to the Professor's
trunk solenoid! This gives reliable starting (a dead cold engine usually starts on the second cranking cycle attempt, a warm engine starts on the first cranking cycle) and the engine runs smoothly without misfiring.
Here's what the internals look like now:
This picture shows the regulator mounted vertically and rotated 90 degrees. The GM trunk solenoid is on the extreme right and activates the horizontal lever that depresses the primer button on the regulator. The blue box will be a junction box to bring in the +12v from the FW to power the remote start, the starter, the cut-off solenoid, and the supplementary fan.
Here's another view:
This shows from left-to-right: the primer solenoid, the cut-off solenoid attached to the regulator, the feed block, and the Beam micro-vac switch. You can barely see it, but the adjustable temp switch to activate the supplementary fan is mounted on the cylinder just below the feed block.
Looking the other way:
The "mailbox" looking thing is an insulated enclosure for the muffler. I initially wrapped the header, muffler and exhaust with header wrap, then decided to insulate and enclose the whole thing for further heat reduction. The disconnected wires seen go to the supplementary cooling fan in the "lid". The fan is a 500 cfm that hangs down from the lid to suck hot stagnant air from the genset - the bottom of the unit is totally open as originally designed. You can also see the 1/4" Hardiebacker panels that are attached to the foam-lined metal enclosure panels that originally came on the DuroPower. I glued them to the foam lining with 3M 377 adhesive - this lets them "float" and seems to help with sound abatement. The black umbilical in the center of the picture is the harness going to the waterproof remote start box on the other side of the panel.
One more shot externally:
This shows the open remote start box and the genset's control panel. I intend to eventually put a water-resistant cover over the control panel, so I ditched the key-start switch since it protruded too far out of the panel. I replaced it with a heavy-duty push-to-start switch and a separate "on/off" switch. It is wired so that a low oil level, loss of vacuum (engine died), manual select of the "off" switch or a button on the remote will break the ground to the cut-off solenoid and stop the LPG supply to the engine. The 30A outlet was not a "RV" outlet, so I pulled out that outlet and wired a RV pigtail (you can see it hanging from the bottom of the genset - this is temporary - I intended to eventually wire the 30A circuit into the FW with an automatic transfer switch). I took the duplex 20A outlet and put a single 20A outlet (the white outlet on the panel) where the 30A used to be. I'll probably mount a digital thermometer where the duplex outlet is blanked off. One other detail - I added the aluminum angle end pieces to the metal panels. The enclosure metal is thin and if you over-tighten a mounting bolt, it bends the edge of the panel. The angle reinforces the edge of the panel and distributes the pressure evenly. I also lined the inside edges with foam gasketing both to allow more even sealing pressure and also cut down a little more on sound abatement.
I still have to fashion a "lid" to divert water and form a duct for the cooling fan - hopefully, I'll get that done soon. Then all I have to do is bolt it to the FW's mount, connect the +12v, and if time permits, extend the FW's LPG piping so I'll have a quick-connect on the rear of the FW to plug the genset into. For now, I have a regulator with a quick-connect on a 20 lb bottle.
Regards,
John
The "new" CPE 46538 model with electric start/remote control will have a suggested retail price of $479. I would imagine it will be discounted by Costco. For comparison, the 36540 manual start has a suggested retail of $399, an average discounted price of $349 and now a special 6 month price of $299.00.
The 2000 watt digital will have a suggested retail of $599. Again, I would expect the "street price" to be lower.
The 2000 watt digital will have a suggested retail of $599. Again, I would expect the "street price" to be lower.
Some preliminary test data on my much-modified DuroPower 3500ES!
I put the Hardibacker "lid" where the gas tank used to be and cut an 8" hole over the end with the insulated muffler enclosure and the generator (figuring that's where the heat is most critical ... the engine has forced air cooling and it can take care of itself!) The ProComp 500 cfm fan is mounted to the underside of the Hardibacker and is sucking accumulated hot air and blowing it out. The bottom of the genset is completely open as originally designed. Originally there were a few vents in the enclosure panels on the sides and my Hardibacker lining has closed those off, so I'm trying a top power vent to account for losing the vents on the sides. The reason you see carpet on the outside of the top panel is that I intend to enclose the top of the genset frame with an opening out the left end - the carpet will help sound abatement inside the duct. I'll line the "lid" that will enclose the duct with carpet, too.
Here's some preliminary temps once the engine had stabilized after about 30-40 minutes: (This is under "ideal" conditions - no load, inside a garage in the shade, ambient air temp about 75 degrees.)
1) Passive heat rising through the fan opening (fan not running): 128 degrees.
2) Generator exhaust air: 148 degrees
3) Air temp approximately 2" above cylinder and avoiding exhaust cooling air from cylinder: 138 degrees
4) Oil temperature: 188 degrees
The 500 cfm fan in the "lid" was connected to a 140 degree switch approximately 2" above the engine cylinder fins and not in the path of the forced air engine cooling. The fan never came on throughout the run. About 5 minutes after shutdown, the sensor got heat soaked enough to run the fan for about 5 minutes - the fan then shut down, waited about 5 minutes, ran for a minute or two, and the repeated the cycle one more time after about 3 minutes and that was it.
Although these are very ideal conditions, it encourages me that the genset never got hot enough to activate the fan while it was running. It'll be interesting to see what happens outside with about 85-90 ambient and running the A/C on the fifth wheel!
Regards,
John
I put the Hardibacker "lid" where the gas tank used to be and cut an 8" hole over the end with the insulated muffler enclosure and the generator (figuring that's where the heat is most critical ... the engine has forced air cooling and it can take care of itself!) The ProComp 500 cfm fan is mounted to the underside of the Hardibacker and is sucking accumulated hot air and blowing it out. The bottom of the genset is completely open as originally designed. Originally there were a few vents in the enclosure panels on the sides and my Hardibacker lining has closed those off, so I'm trying a top power vent to account for losing the vents on the sides. The reason you see carpet on the outside of the top panel is that I intend to enclose the top of the genset frame with an opening out the left end - the carpet will help sound abatement inside the duct. I'll line the "lid" that will enclose the duct with carpet, too.
Here's some preliminary temps once the engine had stabilized after about 30-40 minutes: (This is under "ideal" conditions - no load, inside a garage in the shade, ambient air temp about 75 degrees.)
1) Passive heat rising through the fan opening (fan not running): 128 degrees.
2) Generator exhaust air: 148 degrees
3) Air temp approximately 2" above cylinder and avoiding exhaust cooling air from cylinder: 138 degrees
4) Oil temperature: 188 degrees
The 500 cfm fan in the "lid" was connected to a 140 degree switch approximately 2" above the engine cylinder fins and not in the path of the forced air engine cooling. The fan never came on throughout the run. About 5 minutes after shutdown, the sensor got heat soaked enough to run the fan for about 5 minutes - the fan then shut down, waited about 5 minutes, ran for a minute or two, and the repeated the cycle one more time after about 3 minutes and that was it.
Although these are very ideal conditions, it encourages me that the genset never got hot enough to activate the fan while it was running. It'll be interesting to see what happens outside with about 85-90 ambient and running the A/C on the fifth wheel!
Regards,
John
