Cooling/co-gen update

[Tom Reed]

After running my engine for a year with the thermostat going through wild up and and down swings I decided to deal with the problem. Also hearing accounts of engines running cleaner at 195 deg than 180, it was time to replace the thermostat. In the old configuration the temp gauge on the inlet manifold to the hydronic heating system would swing from a high of 140f to 60 f.

So I started with a nice new Beck/Arnley 195 degree thermostat that was for the same application as the NAPA 253 unit that was installed in the engine. Since I knew the 1/8" hole was to small I drilled 4 - 1/8" holes around the perimeter of the new thermostat. Removed the old thermostat and found the new unit, while the same diameter as the old one was quite a bit larger in the structure on both sides of the unit and would not fit in the engine or the housing. So after a good bit of die grinder work the new unit fit.

Refilled the system with water and fired it up and.... bummer same problem. A big slug of hot water and then lots of cold. So I put a C clamp on the lower hose and after closing off almost all the flow the outlet temp stabilized. So the cooling system was drained again and a ball valve was added to the lower hose. On the first guess the engine came right up to temp and I could feel just a slight fluctuation in the outlet temp. Checking on the hydronic water inlet manifold showed a nice steady temp of 95f with a 2KW load on the generator. Ran the system until the bats were charged and with no load the input water temp was steady at 85f. Turned on a 1.1KW load and the temp rose to 89f.

Then got the ir temp and measured 191f on the water outlet, 195f on the injector and 450f on the exhaust outlet flange. Things are looking good. Next we need a few cloudy days to see if it will now burn my b100, WMO and RUG blend with out carboning up the injector.

[rcavictim]

Might want to remove the handle from that restrictor ball valve once it is set the way you need so it cannot accidentally get bumped closed.

[fabricator]

I put a 205 degree in mine and there was a very noticeable difference in the amount of carbon on my injector then when I had the 195 in it.

[Geno]

I put a 205 degree in mine and there was a very noticeable difference in the amount of carbon on my injector then when I had the 195 in it.

That's interesting. I burn WVO and have a 195° t-stat. The carbon isn't that bad but I wouldn't mind less. Do you have a part # for the 205° t-stat?

Thanks, Geno

[fabricator]

I saved the box, I'll see if I can find it now.

[fabricator]

It's a NAPA part # 383, I had to do a little work on the housing also, I stuck it in my lathe and used a boring bar to make enough clearance, I just using the stock housing also, I also had to take a die grinder to the hole in the head, there was so much casting flash the stat wouldn't fit, it went quick because the flash was less that 1/16" thick.

[Geno]

Thanks, I had to modify my head and housing as well.

Geno

[playdiesel]

My run time with these engines is nowhere near most others here but the 6/1 we built for use as an grid outage plant and for use at shows to run fans lights etc does have a few hours of run time. All it has is a valve in the lower hose. I set it with a light load so the block runs hot to the touch and figgured to have to mess with it as loads change but that has not been the case. Seems like the thermosyphon regulates itself just fine once the flow is set? Warm up takes a bit longer as flow is not stopped as with a thermostat but it warms up quick enough to suit me. I dont run a gage I just go by the feel method. This is with a tank, My second 6/1 is set up the same except has radiator but I dont have enough hours on it yet to know how it is going to regulate.

[Tom Reed]

Might want to remove the handle from that restrictor ball valve once it is set the way you need so it cannot accidentally get bumped closed.

I actually used a 1" water service valve since that is what was found in the 1" pipe fittings bucket. It has no handle, just a flat blade for a T handle wrench. I also took a sharpie and marked the position on the valve. I anticipate the valve may need to be opened more if the generator is run when the heat is not needed in the house and I want to be able to put it back in the same position afterwards.

I got my thermostat on Rockauto.com and looked for a 205f thermostat for the same application as the as the NAPA 253 that was in there and the best I could find was a 195f. I'll run this for a while and see how it works. I'd imagine that just running at a steady 195f instead of a pulsing 180f - the cold slug should make a big difference.

The system is still setup with the standard tank cooling with the upper and lower lines Tee'ed into for the hot and return lines. Even after a 3 hour run the other day, the tank was barely warm to the touch. I to am amazed how stable the temp is by adjusting the flow in the lower hose. We'll see how stable it stays today as it will probably have an 8+ hour long hard run charging batts.