Full load test on a 6/1

[veggie]

I did some full load testing today on the new 6/1. (Driving an ST5 head)
As I increased the load to 3kw I was expecting a lot of grunting and some black smoke.
Neither happened.
The engine note changed, but she just kept chugging along and cranked out the 3kw as if it could do it all day.
I don't have the ability to test 3.2kw or 3.5 kw so my question to other 6/1 users is....
How much can we get from a 6/1 before it becomes overloaded.?
What kinds of loads have you pulled (intermittent and continuous).?

Here's a video of my unit putting out 3kw...
http://www.youtube.com/watch?v=hHebEYSsfeo

PS: Does the ignition knock sound excessive ? or is that normal for the "roids" ?

cheers,
veggie

[Ronmar]

Well my first question would be How exactly did you determine you are loaded to 3kw?

Unless you are measuring voltage and current to the load, you really don't know.  Those heaters being a fixed resistance only consume their 1.5KW at 120V input.  Knowing that the harmonically excited ST head experiences voltage droop under load, I would hazard a guess that you are not even loaded to a full 3KW...  As an example, I use a 2KW and a 1.5KW baseboard heater as dummy loads.  I have raised the output of my ST slightly to compensate for line loss getting to my house. With both loads on, I droop right to 120v per leg at the loads.  I am getting close to the full 3.5KW and it is a little excessive for the engine.  It has a pretty good exhaust thump and quite a lot of black smoke.  That is a good indication of reaching the maximum engine capacity, when the smoke shifts from blue to black.  Another good indicator is RPM/frequency droop.  With the utterppwer governor mod, I set RPM to get 62HZ unloaded.  It droops to 58HZ at a full load of 3KW.  It does this very consistently. 

It is hard to tell on a youtube video audio track, but your engine sounds OK in that video. 

[veggie]

Hi Ronmar,

You're right about the crude method of measurement.
About the only thing I can add is I ensured that the rpm of the engine was 650 and the gen head was 3600 under full load.
I adjusted the governor to meet the required speeds once the 3kw was applied.

veggie

[mobile_bob]

my take on this subject is the 6/1 is typically overrated, and generally more like a 5/1 at elevation

reasoning being 6hp equates to a bit over 4.4 kw mechanical

if the st head is 80% efficient, and the drive eats up 2%, the aggregate is 78%

4.4 x 78%= 3.4 kwatts, that should be the full max load
and i would expect some dark smoke, but not billowing black smoke, and
it should hold at least 58hz without falling off, also the rack should not be stuffed to full throttle.

diesels lose 3% for each 1000ft of elevation above sea level, so at 3k ft elevation one might expect 3kwatts max output
with some smoke and a stable 58hz.

also i agree with Ronmar and his assessment of the heaters used as a load bank, their load shifts all over the place
with every shift in rpm, and ever draft that blows over them.

i about went crazy trying to get an accurate load reading, watching volt and amps, logging every shift, averaging etc
is very difficult to do, along with timing the event, and keeping track of fuel weight of volume,, takes about 6 eyes, many hands, and
more brain computing power than i have to track it all.

that is why i got so excited about the GE kw/hr meterhead, it can be set to measure and readout in watt/hrs, and does the whole thing
very well, it doesn't care about shifting loads due to volt/amp/rpm/breeze/phase of the moon or whatever,, it measures and calculates on
the fly quite accurately.

all i do is verify that my rpm is as close to 60hz as i can maintain it, stabilize the load, temps and then run the test which measures
fuel used for each 1000watt/hrs generated. i just mark off at each 1000 watt/hrs generated by start/stop fuel weights, and continue
on until i have done 3 steps for each load level, this spreads the fuel weight over the scale on the scale.

then it is a simple matter of punching in the results into the spreadsheet program, and a graph is auto plotted

now i get nice clean graphs, that are based on repeatable results

before my data points were all over the place, making rough graphs, and also hard to replicate testing,, which always left me very
uncomfortable.

consistent and replicable data is very useful in relative results, accurate data that is also consistent and replicable is a quantum leap
ahead in my opinion.

bob g

[veggie]

Bob....

You know some parts of India are actually BELOW sea level.?
Maybe that's where they do the dyno testing and stamp it as a 6/1. .... instead of a 5/1 like the Dursley engines.

cheers,
veggie

[Ronmar]

Do you have a kill-a-watt?  IMO no one who makes their own power should be without one.  That would allow you to set the correct output freq and monitor output voltage.  It is only good for about 1.8KW of thruput, but would allow you to determine exactly how much of a load one of those 1.5KW heaters actually is on your set at 60HZ...  Harbor freight tools has them in their stores and on their website.  Probably the best bang for your buck as far as power monitoring test equipment is concerned.

If I recall correctly the dursley 5/1 was rated at 600 RPM...

[veggie]

ronmar,

Will pick up a kill-a-watt ASAP !

thanks,
veggie

[wrightkiller]

ebay.com
the-parts-powerhouse/   good prices on kill-a -watt

http://cgi.ebay.com/P4460-P3-Kill-a-watt-EZ-Electricity-Meter-Usage-Monitor_W0QQitemZ120513633617QQcategoryZ294QQcmdZViewItemQQ_trksidZp2773.m263QQ_trkparmsZalgo%3DSIC%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%26otn%3D12%26po%3DLVI%26ps%3D63

[mobile_bob]

Bill Rogers explains how to make a simple modification to the kill a watt so that its useful range is dramatically extended
using a current transformer or two.

iirc it is outlined over on utterpowers web site.

fwiw
bob g

[Geno]

I use Bills method. Works great! The new KAW's have a memory and are programmable for your electric rate.

Thanks, Geno

[cujet]

Rocketboy's 6-1 running at 730 RPM produces 4,600 watts maximum with plenty of exhaust smoke. It is not capable of any more. It produces 4,000 watts with ease and no exhaust smoke. We have not run the engine at a lower RPM, due to pulley configuration.

[mobile_bob]

you can hardly call his engine a 6/1 anymore as it is more closely an 8/1 is it not?

bob g

[Ronmar]

my take on this subject is the 6/1 is typically overrated, and generally more like a 5/1 at elevation

reasoning being 6hp equates to a bit over 4.4 kw mechanical

if the st head is 80% efficient, and the drive eats up 2%, the aggregate is 78%

4.4 x 78%= 3.4 kwatts, that should be the full max load
and i would expect some dark smoke, but not billowing black smoke, and
it should hold at least 58hz without falling off, also the rack should not be stuffed to full throttle.

I definitely agree with 3.4KW electrical being about the limit.  At 300' above sea level, My full loadbank is just a little shy of the 3.5KW as I am just a little under 120V per leg at that point, but it is pretty close.  With that much load, the frequency has started to fall off and is around 57.5HZ  This is of course is perfectly normal as a mechanical governor tied to engine RPM must have a decrease in RPM in order to increase the throttle.  The trick is to set it a little high unloaded so it droops across your desired frequency at your typical operating load.  Starting at 62HZ warm and unloaded, it settles at right around 60HZ at 2KW.  It is also very consistent.  Because of this I can tell the state of engine load from inside the house using the Kill-a watt displaying frequency. 

With nearly 3.5KW, the exhaust is altered,  containing much more grey/black smoke.  It will maintain that much load, but you can tell it is working to do so and has a much more pronounced exhaust whump.  I use this much load to test my heat recovery/cooling system mods as it never really sees this much sustained load in operation.  It only sees anywhere near this load when the wellpump, reefer and freezer have the audacity to cycle on all at the same time.  Been keeping my eyes open locally for another  4'/1KW baseboard heater...  Or my next order with surplus center will include one of those, as they usually have baseboard heaters in stock.  They make excellent loadbank loads...

I also agree with Bob IRT Rocketboys trailered single.  It is a wonderfull piece of machinery craftmanship, but is probably closer to 8HP than it is to 6 IMO...