still...
I'd rather have the totalizer...that's the beauty of experimental, do what you want and be happy...
I'd rather have the totalizer...that's the beauty of experimental, do what you want and be happy...
The totalizer also can give you estimated fuel left at destination when tied into your GPS (assuming it's calibrated correctly) which greatly assists in making the decision about a fuel stop or push on.
No. GPS is a fundamental change in how you navigate in a radio based environment. (pilotage is not the correct comparison, VOR and NDB are).
In this case a fuelntotalizer and a fuel tank gauge are providing the same service. How much fuel is remaining. Fuel totalizers largely came about because of inaccurate fual gauges. Fuel gauges have historically been inaccurate because of FAA lighting and other requirements constrained possible solutions. We do not face such constraints. So why continue with the bandaids?
Tim
Not really, totalizers don't know how much is left - only how much you've used. For example, if you have a fuel leak or lose a gas cap and have fuel siphoning out of the tank, you could have much less fuel than you would think by only looking at the totalizer. I want (and have) both, gauges and flow, thank-you very much.
Any chance you could use an arduino to do digital to analog conversion?
Have you considered having a heavier wheel made for inside the red cube? Or have a heavier wheel with fewer 'teeth' and larger pulse width made? You would have to recalibrate the EFIS for the smaller pulse count, but that should not be too difficult. Or even remove half of the teeth on the existing wheel in order to help keep it from reversing to the previous tooth.
I had the same idea. Unfortunately, the Cube is designed to make disassembly impossible without breaking a potted wire (seen here at 5 o'clock):
We tend to focus on cruise data when comparing different engines but don't discount the gains available during taxi and climb. The TDI is a close match at cruise but beats the spark ignition engine hands down at full throttle when comparing fuel flow. Will be interesting to watch this project especially the weight loss phase.
The average 7.1 GPH over 100 hours is very good but you gotta wait for the whole story. With 260+HP, the Lycs ROC is likely to be better to medium altitudes so you you don't need to spend so long in the climb. We could shut the fuel right off or almost on an EFI Lyc in the descent too if you wanted and you can go LOP even in the climb if you pull the prop back and get below 75%.
Depends on what you call "medium altitude".
Scott's current engine is a experimental mule with about 230 HP. The long term plan is replacement with a new CD-265 (aka a TDIO-304-A on the TCDS), probably with a prop upgrade.
Flown solo, the 540 should initially out-climb the diesel, based on lighter weight and equal thrust. However, any advantage will bleed away rapidly with altitude gain. The turbo diesel will make full rated power to around 10K, and 90% to about 13K.
So, an IO-540 time-to-climb advantage is unlikely if the plan includes going to an efficient cruise altitude, and the diesel will burn less fuel (about 14 GPH) for the duration of the climb.
Look for a feature in Kitplanes. And yes indeed, Scott is to be complimented for his very professional approach to a new installation.
Agree, but the present engine is 230hp and many 540s being installed in RV10s are 280-290hp these days.
The RV10 climbs very well, from SL to 7500ft, pretty easy to do that climb in around 6 minutes at fairly high weights. That's 1/10th of an hour. Let's say average burn during that climb is 22GPH, that's only 2.2 gal burned in the climb.
I'll certainly look forward to the KP article to find out more.
I havw an RV-10 with a Thunderbolt engine in it, stock compression,and I always check fuel burned at TOC, mostly out of curiosity to see how the flight planning worked. I can usually count on 5 gallons burned from start up, taxi, and TOC to around 8K'-11K'.
Just offering a data point.
Vic
Here you go Ross,
OAT 49F -- Baro 30.13-- 5000ft.
164KTAS-- 152KIAS -- MAP 75.5"-- 2190RPM -- 10.6GPH---200HP (calculated)
This is off a screen shot I have but haven't posted it due to image hosting issues.
I checked the data stream to verify the fuel flow was reasonable to make sure it was not the high or low. FF reading currently varies +/- .5gph due to injection pulses.
Interesting. Most of us would see at 5000'around 177-180HP and 164TAS, and as you would expect about 45-46LPH or 12.0-12.15GPH.
Besides the CR benefits the cooling drag must be an issue?
Scott, I was having a conversation with another guy today about your diesel RV10. We were curious as to what MAP/RPM do you have to maintain on descent to keep the fires lit so to speak? Approx fuel flow at that power setting? Thanks.
Ross,
The factory answer (currently) is 45"MAP and a CHT of 212F until landing on runway is assured. FF at that power reads approx. 4gph.
FF accuracy drops as the rpm falls below 2200rpm so it could be a little less.
To be honest, I only pull it back that far when I want to slow down in the pattern. Descent at 65"MAP is about 500-700fpm and approx. 160KIAS. And to be honest, I have never pulled it back to 45" and maintained cruise airspeed to see what it would do. Will have to check that out sometime.
So far, I have yet to encounter any conditions were it has come close to failing to light. I've flown from downwind to touchdown at idle (32-34"MAP) and it has always responded smoothly. On a 30F day with power at idle from about 500ft on final, only one CHT approached the 212F limit in the flare. There is a small power lag from idle as you would expect in a turbo diesel, but not excessive.
Maybe not a drag thing, turbocharged (after cooled) diesels will increase combustion cycle temps with altitude and the turbo compressor pressure ratio increases too. The temps will tend to increase heat rejection to hot parts, and the pressure ratio yields higher pumping losses, both of which will reduce the BSFC and may throw off his HP estimates. Without a vacuum chamber ($$$$), it is very hard to simulate this on the ground, so a torque meter would be needed in the air to get a more accurate assessment of power.
So, even with fixed RPM & fuel flow, the turbo-aftercooled engines will loose a bit of power with altitude.
Very interesting. Thank you.
Would an in-flight re-start attempt be with the glow plugs? Sorry, never owned a diesel of any kind. I find the differences like boost at idle, fascinating.
Knowing the reasons for the C182 debacle being scrapped I am keen to see how this works.
Relights were a problem for the 182.....but for a whole host of other reasons than the CHT
Charlie,
I actually called the folks at FloScan to talk with them about their diesel systems. The engineer couldn't hang up the phone fast enough when I explained what type engine I was using. It didn't matter that it would be a certified aircraft engine.
Most marine diesel FF meters that would work speak DIGITAL and aviation displays speak ANALOG. The problem aviation version of the FloScan and Red Cube have are that the Bosch mechanical injector pump introduces 3200 pulses/minute(idle) and 8800 pulses/minute(flight) into the incoming fuel stream. Think shockwaves or instantaneous microstops to the incoming fuel. This drives the turbine meter systems nuts. And yes I've looked into digital to analog convertors. I've yet to find one that can work with the few number of pulses per gallon the system would produce at idle. I actually found a system that was designed to account for these pulses, but again, its output was digital.
I knew when I committed to installing this engine, I would be on the cutting edge. I just didn't think I would be the FIRST one, I expected an OEM to get there first.
Scott,
Do you have any data on the compressor discharge temps and intercooler outlet temperatures. Curious.
Thanks
Second year at OSH with the TDI.
-Trip up took two days, three legs and 7.6 hours-After one trip around Rush Lake on Sunday, I went back to Watertown for the night.
-Trip home took 4.6 hours with a fuel stop in DKB.
Total time--12.2 hrs.
Total Fuel burned- Departed home with 64gal, bought 71gal, and have 40gal left in the tanks.---95 gallon burn.
Averages out to 7.8gph--- at $3.15/gallon.