6/1 w/st5 baseline fuel consumption ?

[mobile_bob]

ok guys here is what i need or would like to know.

most folks seem to run a 6/1 with an st5 using a serp belt
so i would like to know if anyone knows or can report what the fuel consumption
of this combination is per hour with "no" electrical load.

just the engine running at rated speed, driving the genhead at 1800rpm

what i want to know is how much fuel does  it take to provide for frictional losses, pumping losses, sound, windage, vibration
etc,, everything but electrical output.

i am working on building a multi variable formula, and this is one variable i figure there should be some hard data on so i don't have to
guess or calculate.

i would also be interested in other engine/gen combinations as well such as changfa's, petters, big twins and other genheads.

it would be interesting to have a good amount of data to determine if there is a relationship with size, rpm etc.
but at this point the 6/1 and st5 coupled with a serpentine belt is of primary interest to me.

thanks guys
bob g

[oliver90owner]

Isn't this information available on Utterpower?

Regards, RAB

[mobile_bob]

RAB
i would have to scour utterpower to see if the info i seek is there somewhere, but i doubt it.

i can find info on fuel consumption for producing X amount of power from a 6/1 and an st5, but
my hope was to find an accurate consumption number for just the losses of the components running at
rated speed.

it stands to reason that the first kwatt generated will consume more fuel than subsequent kwatts,
i am trying to determine just how much more does the first kwatt consume in fuel compared to the 2nd and 3rd kwatt.

thanks
bob g

[MacGyver]

There's 2 or 3 different pages and/or graphs on the Utterpower site that show fuel consumption.
It looks like the baseline "0 watts output" for a 6/1 - ST5 combo is about 0.1 GPH.


FWIW, in order to search specific words *within a particular site* using Google is easy.

For instance:

I want to search for the word "consumption" within the Utterpower site...
Simply type:

site:utterpower.com consumption  (Note where there's spaces and where there's not... very important)

That will show all the pages with the word "consumption" inside the Utterpower site ( I got 8 ) but no other sites.
Rather handy actually...

[MacGyver]

Once I've got a few dozen or so hours on my 6/1 - ST7.5 combo so I know it's "loosened up" a bit, I'll endeavor to get some accurate numbers on my fuel consumption so there's some data to feed the "6/1 with a ST5 vs ST7.5" aargument.

[mobile_bob]

McGyver:

hey thanks for the heads up,, i have been aware of the google search of a site function, but i guess i am either to preoccupied or lazy to
have given it a go,, maybe it is time i availed myself of this tool?

anyway, i appreciate the info

and look forward to your results with the setup you are running, to see how it compares
what do you think the results might be? i am thinking it might be a touch more than .1 per hour,, but it is hard to imagine it would
be appreciably more. i guess if it turns out to be significantly more, that would make a case against oversizing a head especially if one is going to run
long hours with pump diesel fuel and light loads ?

.1 gallon per hour to cover the baseline losses,, not bad
that is about 13,500btu's to cover the baseline
figuring about 1/3 of that being converted to mechanical power, works out to be about 4500btu's for mechanical work to spin everything.

interesting indeed

thanks again

bob g

[oliver90owner]

i would have to scour utterpower to see if the info i seek is there somewhere, but i doubt it.

Thanks Mac,

The first page I looked at was 'Listeroids' and there it was.  I did not think it was too difficult to navigate Goerge's site.

Bob,

No point in any UK data then?  All 1500 at the head


it stands to reason that the first kwatt generated will consume more

Yep!! and worse still for the calculation of what it costs to produce absolutely nothing!! (the answer is 'infinite', for the less mathematical).

Regards, RAB

[ronmar]

FWIW  my 6/1-ST-5 with an 8 rib serp belt and no electrical load did 477CC or 0.1260101 gallons in 1 hour last night.

Ron

[MacGyver]

Excellent! Some real data!

Errrr... wat did you use use to measure the fuel (or the time!) to that many decimal places? 

Does your 6/1 have a thermostat?  Just curious..

Thanks for the data!

[ronmar]

My 6/1 has a thermostat, and all the tests I am doing are at operating temp. 

I made up an alternate fuel feed that consisted of a 5/16 clear line with a "T" in it to incorporate any fuel returned from the injector overflow port.  To the top of this line I connected a inverted small plastic oil bottle with a hole in the bottom of it to use as a funnel.  Into this I injected 50CC of fuel at a time.  To start I let the fuel level drop down the clear line to a measured mark and started the stopwatch and injected 50CC.  I repeated this process right up untill 60 minutes had ellapsed, but at the end, I added fuel slowley, keeping the level below my measured timing mark.  At exactly 1 hour I closed the rack and let the engine stop, then carefully added fuel from the last syringe untill the fuel was at the starting mark.  This gave me a total to within a CC or so.  The convert program I used converted tyhe 477CC to that many decimals so I included all the info:).  I also noted that it took, to within a second, the same ammount of time, 4min 17sec, to consume each 50CC syringe.

I did 2 more tests tonight, but not full hour runs.  I ran two 50CC syringes thru for each test, and again, it took the same ammount of time to the second to consume that ammount of fuel twice in a row.  The first was for the engine alone, which worked out to be. 0.07477 Gal/Hr(50CC in 10 min 36 seconds).  The second test was with the generator connected, but the field disconnected and the output shorted thru my load bank resistors to bleed off any residual current.  That test showed 0.08693 Gal/Hr(50CC in 9 min 7 seconds).

Next up will be some load tests but I have to get my instrunmentation and load ducks in a row first...

Ron

[oliver90owner]

Ron, and others setting about measuring fuel usage rates,

Two things.

First: Maths dictates that one can never giver an answer to more significant figures than the 'coarsest' input data was measured to. In your case the 477 was the  limiting value, so only 3 significant figures, at most, are really relevant.

Consider the average of 1 and 2. If each figure is only to the nearest one digit, the average must be 2  (ie 1+2 =3;  3/ 2 =1.5;  1.5 rounded to the nearest digit is 1).  Now consider 1.0 and 2.0; now we have values assigned to plus or minus 0.05 (more accurate(?) or precise), so the answer this time will be 1.0.  Much more precise than the first example by an order.  Hope you understand what I mean.

Second : A simple T from the feed line, with an isolating valve in the feed line, and an upright transparent leg to the height of the top of the tank is perfectly adequate for measuring fuel usage, much like you did.

Leak-back can be measured separately or plumbed into the extra upright leg during the tests - but it will be pretty well constant for any fuel at operating temperature as far as simple tests are concerned. 

When the fuel is fed from the tank supply the level in the upright will be at tank height.  When the tank valve is closed the only fuel available is from the upright leg and you can time very accurately, and repeatedly, between two set marks on your upright.  Soon after the level passes the lower mark you do not forget to open the main fuel supply again!

You can measure the amount of fuel accurately between the marks, by whatever means you may wish to provide.  An analytical burette tube (volumetric) as your upright is a good alternative to running off the said amount and weighing on analytically accurate scales.

Really all it saves is filling syringes but does make repeated readings (timings) as easy as possible.

Regards, RAB

[mike90045]

Won't Ambient and Fuel temperature vary the burn rate ?

Did you happen to record those ?

Pump diesel ?  Veg Oil ? BioDiesel ?

[ronmar]

Ambient temp around 70F in the shed.  Fuel was #2 offroad diesel.  I am about 350' above sea level...

Here are the 1KW fuel consumption figures for tonights testing.

I found a 900W heater and with my slightly higher voltage output, it works out to 950W(247V@3.85A).  Add to that the 50W Taco cooling pump and we are there.  At that load, the engine consumed 50CC at a very repeatable 4min 8 seconds with the generator producing 60.2HZ.  That works out to 726CC or 0.1918 GPH.

Hopefully 2KW tests will happen tomorrow night and I can graph some of this stuff.

[Tom]

Fascinating numbers Ronmar. It looks like you are on tract to match the numbers from George Bs web site of .125 Gal per KW. That was with WVO and I've read the number is .11 G per KW on pump diesel.

[ronmar]

2KW @ 59.8HZ:

242VAC@8.30A = 2008.6W.  50CC in 2min 59sec = 1005.59 CC/HR or 0.2656 Gal/HR... That is a little more in line with .125 Gal/KW/HR.

Ron