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HP/Fuel Consumption Tests: Saito FA180, FA180CDI, FA180HC CDI BBC

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Old 11-12-2012, 06:23 PM
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SrTelemaster150
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Default HP/Fuel Consumption Tests: Saito FA180, FA180CDI, FA180HC CDI BBC

I finally got an ideal day for testing the power output differences for my Standard compression Saito FA180 on glow ignition, the standard compression FA180 W/CDI & the High Compression FA180HC CDI BBC (FA220 Big Bore Carburetor) All testing W/the same 15% Cool Power glow fuel

For those not familiar W/the high compression FA180HC project, an illustrated write up is available [link=http://www.rcgroups.com/forums/showthread.php?t=1754616]HERE.[/link]

Since the FA180HC BBC was on the test stand I double checked the ignition timing. The timing was set @ 34* BTDC. That will give 34* BTDC @ WOT when running @ high RPM. I'm not sure what the advance curve is, but the 24* retard @ start would give 10* BTD ignition timing @ start & idle.

The 220 Big Bore carburetor has the same bolt pattern as the 150/180 carburetors, it is 12mm bore (the 180 carb is 11mm. the 150 10mm) I bored the updraft portion of the FA150 manifold I had on hand out to 12mm. The horizontal runner where the manifold interfaces W/the intake port was bored out to the standard FA180 ID to match the 180 intake port.

Interesting note: The aluminum intake gaskets that come W/the FA180 are smaller in I D than either the intake manifold or the port on the cylinder head. It appears to be the same ID as the 150 port/manifold. Since I have not had any issues eliminating these gaskets on any of my 150/180 engines, I chose to eliminate it for a smoother transition from the manifold to the intake port.

After fiddling W/the HSN, the FA180HCCDI BBC spun the Dynathrust 18x8 prop @ a solid 8400 RPM flashing 8500, idle was steady 1100 RPM. @ 8450 RPM that generated 3.44HP W/20.44# Thrust.

The standard compression FA 180CDI had the timing checked & set @ the same 34* BTDC.

After tweaking the HSN, the FA180CDI spun the same 18x8 prop @ 8000 RPM flashing to 8100, idle was a steady 1200 RPM. @ 8050 RPM that generated 2.98HP W/18.55# Thrust

The CDI was unhooked, the sparkplug replaced W/a glow plug. The needle setting were opened up to OEM start up specs & the engine started on glow ignition.

After setting the HSN & LSN, the FA180 on glow ignition spun the 18X8 prop @ a steady 7900 RPM, the idle was a rough 1400 RPM but it was reliable. @ 7900 RPM that generated 2.81HP W/17.86# Thrust.

CDI ignition gave an additional 150 RPM, .17HP & .69# of thrust over glow ignition & reliable idle was was 200 RPM lower.

The compressionn ratio increase to 12.77:1 from the stock 9.56:1 coupled W/the 12mm FA220 Carb really brought on the power.

The increase for the standard compression F180CDI version was an additional 400 RPM, HP increased by .46HP (15% HP gain) W/1.89# additional thrust (10% thrust gain) & another 100 RPM lower idle speed.

Comparing the gains from the standard glow ignition FA180, to the FA180HCCDI BBC, HP went from 2.81 to 3.44, .63HP gain, (22% HP gain) thrust increased from 17.86# to 20.44#, a 2.58# gain (14% thrust gain) W/300 RPM slower dependable idle speed.

This puts the FA180HCCDI BBC squarely in the power output range of the FA220 W/much better fuel economy & less weight in a more compact engine package. I am very pleased W/the results.
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Old 11-12-2012, 06:33 PM
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Default RE: HP/Fuel Consumption Tests: Saito FA180, FA180CDI, FA180HC CDI BBC

a 450 rpm gain is significant
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Old 11-12-2012, 07:11 PM
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Default RE: HP/Fuel Consumption Tests: Saito FA180, FA180CDI, FA180HC CDI BBC

Quote:
ORIGINAL: w8ye

a 450 rpm gain is significant
From the standard glow ignition FA180 I gained 550 RPM W/the high compression version running CDI W/the 12mm 220 BB carb..

The 12mm 220 Big Bore carb really woke up the high compression engine. It seems to be much snappier when the throttle is blipped. At 1st it didn't seem to gain a lot on top RPM, but the ignition timing was about 22* BTDC. I had been monkeying around W/it when I did my previous tests & got it a bit retarded. I checked it & advanced it to 34* BTDC & that really livened things up.

The 28* initial settings for CDI are tailored to gasoline. The slower burn rate & higher octane of methanol needs more agressive ignition timing to get all the potential power out of the alcohol fuel.

I now set all of my glow fuel burning CDI @ 34* BTDC.

I think I might have .035 taken off the case deck of the standard FA180 to bring it up to 12.77:1 CR. That's the easy way. One thing is for sure. Once you do that, it's stricly a CDI engine as it is downright nasty to live W/on glow ignition. I will stay W/the 180 carb/manilfold. There's way more power than needed anyway.

I needed a carb for the FA180HC. The old 150 carb from the doner engine was pretty sad. FA180 carbs were on back order & I wanted a crankcase pressure fuel pump/regulator so I opted for the 220 BB carb that came W/the pump check valves & regulator. Since the standard 220 carb is the same as the 180 I knew ithe BB carb would bolt up to the 150 manifold.

The 3.44HP FA180HC CDI BBC ought to be outrageous on the 73" CAP 232 I plan to mount it on. Maybe too much. If it is, I'll put it in my 89" Dynaflite PT-19 & see how much vertical I can get out of a 16# airframe W/20+# of thrust.

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Old 11-12-2012, 07:37 PM
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Default RE: HP/Fuel Consumption Tests: Saito FA180, FA180CDI, FA180HC CDI BBC

Well done!
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Old 11-13-2012, 04:59 PM
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Default RE: HP/Fuel Consumption Tests: Saito FA180, FA180CDI, FA180HC CDI BBC

I picked up a quart of O'Donnell Speed Blend racing Fuel today. 30% Nitro, 8% oil.

WOW! 8850 RPM, corrected for the 50*F ambient temperature, the 18x8 prop @ 8850 RPM generates 23.21# of thrust. The engine is making 3.95HP W/the 30% nitro!

I even saw some 9K+ flashes on the optical tach, but 8800 was the base flashing back & forth to 8900.

So much for the myth of no power boost from increased nitro W/CDI.

From the 15% Cool Power setting, I had to open the HSN a bit less than 1/4 turn, the LSN was opened 1/2 turn to get a good idle/transition.

I am definately going to reduce the deck height on the standard compresssion FA180 to get to 12.77:1 CR

I won't need the 220 BB carb & 30% fuel for the CAP 232, the standard 180 carb & 15% Cool Power should be ample power for a plane < 10#.

23# of thrust in my 16# Dynaflite PT-19 ought to make for crazy vertical!

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Old 11-13-2012, 08:03 PM
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Default RE: HP/Fuel Consumption Tests: Saito FA180, FA180CDI, FA180HC CDI BBC

That's some serious power!
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Old 11-14-2012, 04:11 AM
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Default RE: HP/Fuel Consumption Tests: Saito FA180, FA180CDI, FA180HC CDI BBC

Quote:
ORIGINAL: Kmot

That's some serious power!
Yep, over 40% more HP than a glow ignition FA180 on 15% nitro!! [X(]

The sound is amazing. It hits max RPM almost instantly. The added torque revs up the heavy Dynathrust prop effortlessly.

If I get time today I want to do a test run of the standard compression FA180 on 15% Cool Power for run time on 8oz of fuel @ WOT.

Then, a test run can be done W/the high compression engine on 30% Speed Blend @ a throttle setting that will yeild the same RPM as the SC 180 @ WOT W/15% nitro. Since it will take less throttle, reducing fuel consumption, comparing run time on 8oz of fuel will give me a better gauge of the cost of running the high nitro fuel.
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Old 11-16-2012, 07:23 AM
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Default RE: HP/Fuel Consumption Tests: Saito FA180, FA180CDI, FA180HC CDI BBC


Fuel Consumption Tests

Yesterday we had another decent day to do some more testing. It was a bit chilly, but but there was no wind & the temperature remained stable long enough to get several test runs accomplished.

I added my FA150/CDI engine to the fray for a baseline. It was a bit overpropped W/the 18X8 DT prop, but it still allowed for a comparison W/approximately 12oz of fuel @ 7600 RPM. The FA150/CDI was within 100 RPM of WOT maximum power. All engines were using C&H Synchrospark CDI set @ 34* BTDC.

I will start W/the poorest fuel economy results 1st. Some of the results were fairly close as far as the time it took to drain the fuel tank. These results are not difinative, but they do show a trend, & the most effiecient combo might surprize some of you.

The fuel tank was filled to a point where the "air bubble" @ the top was observed in relation to a mark. The tank was tilted down @ the raer so the mark resulted in fairly cosistant fill volume.

The engine were started @ a high idle speed, the stop watch was started, & @ 30 seconds, the throttle was advanced to attain 7500-7600 RPM. When air bubbles were observed in the fuel line and/or the engine started to surge. The stop watch was tripped.

Again, the FA150/CDI engine was very near to WOT @ 7500-7600 RPM.

Here are the results starting W/the worst fuel consumption results.

The 1st test was W/the FA180HC/CDI/BBC engine running on O'donnell Speed Blend 30% nitro, 8% lube. This is the 12.77:1 CR engine (HC) W/CDI & the 220 big bore carburetor. (BBC)

FA180HC/CDI/BBC, 30% nitro: Run time W/12oz fuel @ 7500-7600 RPM = 8 minutes

All of the following tests were done W/15% Cool Power glow fuel. While there was a significant inprovement in fuel consumption W/the lower nitro content, over the 30% notro fuel, the differences in run times W/15% nitro in the various configurations were not all that significant. They did, however tend to show a trend toward better fuel economy.

FA180HC/CDI/BBC, 15% nitro 7500-7600 RPM = 10 min 22 sec

FA150/CDI, 15% nitro 7500-7600 RPM = 11 minutes

FA180HC/CDI (OEM 180 carb) 7500-7600 RPM = 11 min 44 sec

FA180/CDI (standard 9.56:1 CR, OEM carb) 7500-7600 RPM = 12 min 10 sec

The stock FA180/CDI showed significant fuel economy improvement over the FA150/CDI. This is probably due to the fact that while the FA150/CDI was operating @ near WOT, the FA180/CDI only needed a bit over 1/2 throttle to achieve the same power output.
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