What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

RV-10TDI Update

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.

So do these, I recommend the lower one :D

hqdefault.jpg


$_1.JPG
 
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.
 
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.

I haven't seen anyone argue against the belt-and-suspenders approach, but I'm a little surprised at the arguments against using new tools to solve old problems. Anyone here still using rotary-dial telephones?
 
I've been looking for existing hardware to solve this problem. Why reinvent the wheel? :)

But as it doesn't seem to exist yet, I'll look into the Arduino. Thanks.
 
Heavier wheel inside the red cube

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.



If the wheel inside the red cube is easily removable, I would volunteer to make a new one for you out of maybe brass or steel or even stainless. I can't imagine it would take too terribly long to do.


Maybe you have already tried this route, but I figured I could suggest it.

Richard from Langaire
 
Research

After a brief research session online, it would appear that the marine industry has potential solutions to your FF issues...I read quite a few data/feature sheets that discussed the pulse issue and momentary reversed flow...Most of the info was on the Maretron site...
 
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):



It passes through the cover, then back through it again to the sensor shown in a previous post.

 
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):

That's one way to do it, I suppose. Works better than the little "warranty void if removed" tape.
 
100 Hours

Approximately one year ago, N104ST made its first flight powered by a prototype CD-230. Today, it passed the 100 hour mark.

Fuel bill for the first 100 hours---$2084.27-----713.2 gallons ------- Price range $2.50 to $3.57
---There are still 33 gallons in the tanks!---

Condition Inspection time is here, so the fun will come to a temporary halt.

Known items to be worked on:
1- enlarge oil cooler inlet duct- oil temps are acceptable but need to be better.
2- CHTs - there is TOO much cooling air.
3- start working on empty weight reduction

I?ll be sure to post any findings from the inspection when its finished.
 
Performance data point

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.
 
Not bad at that low altitude. Should be better at 8 to 10K.

Cool project and nice to see you building up the hours on it.
 
Scott---great job for your perseverance on this project. It was fun helping out!
You have to fly it down to 3J1 when its back up.
Tom
 
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.
 
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%.

Best to compare the diesel against the latest technology and most efficient technique available for the Lyc before drawing any conclusions on actual overall cost savings. Don't forget the price delta either.

That all being said, this is a cool project no matter how the numbers come out. Kudos to all involved with the project.
 
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.
 
Last edited:
On another part of the project, have you had any issues with the propeller, such as surface cracking of the finish near the blade roots ?

Just curious as the power pulses will be a lot firmer than with an IO-540 I am guessing.

I take it the motor is direct drive to the prop.
 
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.:)
 
Last edited:
Propeller

Mike,

It is a direct drive setup. The MTV-9-B-S/198-58B propeller was specifically designed for the CD-230's cousin, the SMA 305.

I have not seen any cracking in the blades. It only recently started throwing a little grease. Sent photos to MT in Germany and they said that was normal for this engine/prop combination. So, its on a watch list for now.

The only other propeller in existence at this time that can be used on this engine is the Kevlar one from Hartzell. I believe it is heavier and was definitely more expensive when I first looked for a prop.
 
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
 
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

Same here. 5 gal is a good round number on average.
 
Tim,

Sorry, I don't have that answer right now. I'll add that to the data I collect when I switch out the -230 for the -265.
 
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.
 
Scott,
I appreciate your hard work along with your willingness to share the good and the bad with us. I hope you find a solution to this because I'd love to follow in your steps!
 
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?
 
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?

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.
 
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.
 
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.

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.
 
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.

Manifold pressure to make the same hp at altitude would remain roughly the same if the intercooler efficiency is good. Delta P increases across the turbine with increasing altitude. This tends to offset the higher shaft hp required from the compressor as pressure ratio increases. On properly intercooled SI engines, hp actually increases at the same MAP at higher altitude.

That being said, with the high pressure ratios the diesel requires, they need massive intercoolers compared to SI engines which operate at much lower pressure ratios. I suspect that the intercooler drag may come close to the engine cooling drag.

Would be fascinating to do a side by side test against a 540 powered RV10 like I did with the Subaru and Lycoming RV6As.
 
Last edited:
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.

I know from the manual that glowplugs are only used for ground starts. They create a localized hot spot in the cylinder to promote ignition. Inflight, they wouldn't have the same effect due to the rapid turnover of the air in each cylinder(my understanding).

The inflight restart procedure is just adjusting thrust lever between 50-90% depending on conditions and may require descent into "warmer" air. With the fuel injection timing fixed relative to a point BTDC, its just a matter of getting the right mixture atomization for auto ignition. Cold weather ground starts are similar in that it may require a thrust lever position between 50-90%, but I haven't needed above 50% and it has always started on the first attempt.

I'm sure there is someone in this group who understands and could explain it better than that.
 
Interesting.

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 :eek:

You also quote high MAP and thus very turbocharger reliant. I trust you wear a chute?
 
I didn't want to contaminate the RV10 speed brake thread. Dan and Scott, from the screen shots, the FF seems very high for the MAP and rpm. Are these valid numbers or do you feel there is some sort of error as Scott alluded to previously?
 
Recall how red cube fuel flow senders are pulse sensitive? Well, the diesel flow provides a plethora of pulsation (go ahead, say it real fast). The fuel system has a high volume return, so there are two senders. The fuel flows are not accurate, and worst at low flow. It's on Scott's punch list.
 
Last edited:
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

David, could you illustrate the reasons the Cessna program was scrapped, and why relights were a problem with the SMA SR305-230?
 
Scott,

Do you have any data on the compressor discharge temps and intercooler outlet temperatures. Curious.

Thanks
 
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.:eek: 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.

An idea to consider. I know that when I encountered this problem with air, the answer was a reservoir to help stabilize readings. I wonder if a fuel reservoir of a decent size between the red cube and injector pump/controller (or whatever device is post-red cube) might not help to take some of the pulsing out of the red cube passages. Clearly, having a diaphragm in the reservoir would make a big difference, but would be challenging to fabricate.

Larry
 
Last edited:
Scott,

Do you have any data on the compressor discharge temps and intercooler outlet temperatures. Curious.

Thanks

Ross,

It has a Bosch T/P sensor that went to the ECU that is no longer part of the system. I am able to read it with an Ohm meter and decode with a table. Not the easiest thing to do but I?ve checked on a 93F day and intercooler out temps don?t exceed limits at max power.

We?re you looking for specific numbers?
 
Yes, specific numbers but don't go to too much trouble with an ohmmeter...

Interested in both pre and post temps in and out of the intercooler. Not sure if you have sensors in both locations though.

Any more updates?
 
OSH trip report

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.
 
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.


So when can I buy one of those engines??!!
 
Back
Top