Micro CoGen.

Quote from: mobile_bob on January 18, 2017, 04:34:27 PM
i personally would not use the drain port as part of the thermosiphon cooling system, the port in my opinion is really not large enough to assure proper cooling, unless you derate the engine loading significantly.

thermosiphon is about as basic as one can get, however it is not all that and a bag of chips,  as with everything there is compromise.

for instance the 195 is basically good for 12hp with thermosiphon cooling at or around sea level and in moderate temperature,  if you are in over 100 degree ambient temps and/or high elevations you will have to derate to maybe 10hp or maybe even less in order to cool the engine properly.

pressurize the system, close it up, put a radiator with temp controlled fan and an electric pump then the same engine is good for about 15hp output in moderate ambient temps and sea level, and the efficiency climbs a couple percentage points over the thermosiphon cooling scheme.

it really depends on what you want to do?  simple = compromised output and efficiency,  complex = higher output and higher efficiency.

had i decided to run longer hours and at part load for most of the time, i might well concur with the simplicity of the thermosiphon design.... but to be honest after learning what i have about a closed system with pump etc i would likely still go that route.

fwiw
bob g

My need is for backup power (MidWest Storms) with changing household loads, the largest are the 3 ton AC @ 30A/240V, 30A/240V Water Heater, or the well pump 20A/240V. 

The ZS1115 is rated for 22hp@2200rpm.  I'm direct driving an ST-10 @ 1800rpm so at most maybe 18hp so I'm already de-rated from an overall work/cooling needed capacity.  I have a new surplus radiator from a 30hp diesel JD tractor, a cooling fan with thermo switch, and a DIY hopper plate with a thermostat.  Another head indicated the coolant drain should be 3/8 BSPT.  I will see what NPT taps I can find locally and drill the block to a larger size.  If that does not work temp wise than I'll add a Bosch coolant pump.  Ideally I'd like to return to the bottom of the block as it would make the overall height more compact. 

Thanks for the info here!!

So what is the consensus on the drain port size being large enough for the coolant return when thermo siphoning?  I made a coolant block off plate with a short dipper pipe for the return but have not run it yet.  Ideally I'd like to return to the bottom of the block as it would make the overall height more compact.  Is the stock size adequate or should I drill and NPT tap it larger and if so what size?  I have a ZS1115 Changfa which should be similar.  I've been collecting parts for years and been sidetracked with having 2 kids.  We had a recent ice storm (luckily no outage) and the generator is back as a priority.

Well I have an "official" Changfa branded ZS1115GM.  So if anyone has some decent specs for mating something to the flywheel hub that would be great.  I have a couple of brake rotors that look like they should be usable.  My plan is to true up a couple of LoveJoy couplers.  Then machine a seat into the hub face of the brake rotor.  Preheat things and then weld the coupler on.  I'll document the process and post up pics here when completed for future use. - JP

Does anyone have some real dimensions for the Changfa flywheel.  The PDF I have shows a diagram but it appears to be a scan of a scan of a scan of a bad 1970s era fax.  I've found someone to machine a drive adapter for me, just need some real specs.

What's your plan for mating the Lovejoy Coupler to the brake rotor?  I'm in the same boat looking to make a direct drive. 

I sourced a cheapo from eBay when these things were more popular, but I don't trust it.  I have a rear rotor from a '96 VW Passat that looks to just be usable with some machining.  There's a snout on the face of the rotor that needs to be removed in order to yield a flat surface to then center and weld on the coupler.  The inside of the hat would need to be machined flat if you were planning to bolt on the coupler.  I also have a rotor from a '02 VW Jetta/Bora/Golf that looks like it could be made to work.  The hat isn't as deep so I'm not sure it will clear the flywheel nut?

I plan to direct drive the gen head and then run the back side of a serpentine belt off the rotor hat to power an automotive DC Alternator and York AC Compressor.