Author Topic: Hold on to your Hatz Northern Tool. I`ll buy Chinese!  (Read 8482 times)

Stan

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Re: Hold on to your Hatz Northern Tool. I`ll buy Chinese!
« Reply #15 on: October 30, 2007, 03:27:48 AM »
Wouldn't fuel consumption be more dependent on load than rpm?
Stan

rcavictim

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Re: Hold on to your Hatz Northern Tool. I`ll buy Chinese!
« Reply #16 on: October 30, 2007, 07:36:20 AM »
Wouldn't fuel consumption be more dependent on load than rpm?
Stan

Only at partial power Stan.  As a rule of thumb I figure if you reduce the engine RPM in half you get 1/2 as many bangs in the same period of time.  Now the engine is only capable of half as much full throttle power at 1/2 RPM so you are going to end up closing back on the fuel rack because the engine will not be able to process as much fuel and point of black smoke will occur higher on the go pedal.  At half speed and point of black smoke the engine will be making half the shaft horsepower and will be using half the fuel as at normal speed and at the black smoke point.
-DIY 1.5L NA VW diesel genset - 9 kW 3-phase. Co-gen, dualĀ  fuel
- 1966, Petter PJ-1, 5 kW air cooled diesel standby lighting plant
-DIY JD175A, minimum fuel research genset.
-Changfa 1115
-6 HP Launtop air cooled diesel
-Want Lister 6/1
-Large DIY VAWT nearing completion

rcavictim

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Re: Hold on to your Hatz Northern Tool. I`ll buy Chinese!
« Reply #17 on: October 30, 2007, 07:53:57 AM »
Really interesting thread here!
My question though, if I run a diesel that was designed for 3600RPM at 1800RPM and load it properly will it be likely to wet stack or will other more important concerns exist?
Seems to me that the load will prevent wet stacking, but valve timing, injection timing, etc might create problems that are way over my head.
Would only half rated RPM also indicate only half fuel consumption or is this question too vague or unanswerable because of not having specific engine information?
Vic

Vic,

I honestly do not know if running an engine like these at way below nameplate RPM will provide enough heat to prevent wet stacking.  I am going to find out as i have now made considerable progress in a power plant that will use a 2600 RPM, 6 HP JiangDong at 500-1000 RPM.  My general feeling is that first you must process enough fuel to get the engine block up to and maintained at engine temp, say 190 -200 degrees F.  In a thermostatically controlled engine with liquid cooling this could be assisted at low fuel through-puts by putting thermal insulation around the outside of the engine block.  The second requirement I think is to have a fierce and hot bang evry time the cylinder fires, even if the bang rate is greatly reduced.  A cold bang is probably the reason for wet stacking, not the rate of them per minute.
-DIY 1.5L NA VW diesel genset - 9 kW 3-phase. Co-gen, dualĀ  fuel
- 1966, Petter PJ-1, 5 kW air cooled diesel standby lighting plant
-DIY JD175A, minimum fuel research genset.
-Changfa 1115
-6 HP Launtop air cooled diesel
-Want Lister 6/1
-Large DIY VAWT nearing completion