Van's Air Force
Don't miss anything! Register now for full access to the definitive RV support community.
409 for an RV-10
- Thread starter AC Aero
- Start date
I suspect that the 409 at 100 lbs lighter will play hack with your weight and balance. I would suggest that you first talk to Ken Kruger at Van's Aircraft about the effect of putting a 100 lb lighter engine on the front of an RV-10 before doing so.
People who have put a 100 lb heaver engine on the front almost always have to add 100 lbs of weight in the baggage compartment to get the WB right, but there is no way to take off 100 lbs from the tail to counter act the loss of weight up front.
I put an MT prop on my RV-10 and that small weight reduction changes the landing trim to max trim with full flaps.
People who have put a 100 lb heaver engine on the front almost always have to add 100 lbs of weight in the baggage compartment to get the WB right, but there is no way to take off 100 lbs from the tail to counter act the loss of weight up front.
I put an MT prop on my RV-10 and that small weight reduction changes the landing trim to max trim with full flaps.
Mike S
Senior Curmudgeon
I suspect this will be far enough forward to also need a new cowling.
Tom Martin
Well Known Member
On the RV10 that I worked on we moved the battery to the firewall and required 50 pounds in the baggage compartment when flying solo. This was not a big penalty as it greatly improved the aft loading capability when traveling and we also saved quite a bit of weight with the forward mounted smaller battery. I suspect that this lighter engine with the prop in the same location as the standard engine and perhaps a heavier battery on the engine side of the firewall would be just fine. Aside from that I am other then the net savings in weight I am not sure if I would want to give up that 20 or 30 hp going from a 540 to this 409 engine. It would be an interesting project.
I don't know about instillation in a -10 but it sure sounds like a nice engine option for the RV-14. It is 13lb lighter and has 20 more HP than the I0-390. 
Last edited:
pierre smith
Well Known Member
I don't know about instillation in a -10 but it sure sounds like a nice engine option for the RV-14. It is 13lb lighter and has 20 more HP than the I0-390.
My thoughts exactly. nevertheless, with the battery on the firewall, a 409 powered -10 would be close to correct CG..after all, you're moving a full sized battery 10 feet (I just measured it on my airplane).
Cosola and Associates in Albany, Ga. build engine mounts and could probably fab one for this engine.
At 75% power, I'm making around 182 HP on my IO-540 and running 200 MPH or better, so I'd think that the lesser horsepower may not be noticed much in cruise, but rather in takeoff and climb performance.
Best,
As I have understood it from a few people that fly the RV10, they have said the CG is a little too far forward. That was the reason for my comments and my original question as to see if anybody is interested in working with us to develop a firewall forward kit.
As to performance @ 75%, I think we should consider the power to weigh ratio, with the 540 (there are lots of flavors so I have taken the IO-540-D4A5 @402 lbs) it is 2.06 lb/hp and with the 409 it is 1.76 lb/hp
I suspect that in the real world you would not actually see much difference.
Regards
Andrew
As to performance @ 75%, I think we should consider the power to weigh ratio, with the 540 (there are lots of flavors so I have taken the IO-540-D4A5 @402 lbs) it is 2.06 lb/hp and with the 409 it is 1.76 lb/hp
I suspect that in the real world you would not actually see much difference.
Regards
Andrew
I believe that if you talk with people that are truly using their RV-10s in a manor that is utilizing the full utility they are capable of, they will tell you that the C.G. is perfect.
If you ask someone that fly's it as a two place airplane a large percentage of the time, they probably would say it is nose heavy (as does someone with a C-182 in the same situation).
If you ask someone that fly's it as a two place airplane a large percentage of the time, they probably would say it is nose heavy (as does someone with a C-182 in the same situation).
pierre smith
Well Known Member
Well said..yes, it feels nose heavy with two up and full fuel but nevertheless, truly solid airplane and I don't add any weight in the rear to compensate because it's not really necessary.
Best,
Best,
Wayne Gillispie
Well Known Member
I added 25 lbs of aux bat/wiring/contactor/fuse block at same station as main battery. Everything else per plans and stock. I love the balance solo, but I have to watch the aft limit. There is plenty of room in rear footwells to distribute the weight. Every flight since 25 hrs has been with a full load and it is fine. I would not want 100 lbs off the front and all of the additional modifications, less power and less climb rate. Yes, you could install firewall reinforcment for battery mount, main battery-PC925, contactor, #2 ga wire up front around the heat/vibration and balance would be very close. I also like having plenty of working room up front. If one likes to build more than fly, go for it.
With my aft full size battery and lighter MT 3 blade prop on the front the CG is perfect for almost all loads EXCEPT 4 adults and 100 lbs of luggage, which means that I have to be very careful when I get in the airplane or the tail will go down hard. I make sure that I am the last one on board so that I can do a last minute walk around and check everything before boarding.
My CG with 4 adults and 100 lbs of luggage is still within CG limits but absent moving the battery to the firewall reducing the weight of the engine by installing a 409 engine would take it out of the design CG limits.
My CG with 4 adults and 100 lbs of luggage is still within CG limits but absent moving the battery to the firewall reducing the weight of the engine by installing a 409 engine would take it out of the design CG limits.
Thanks for the confirmations guys.
The airplane was specifically designed to carry 4 true adult sized people and bags ( the reason some think it a bit nose heavy if the fly with just two). As already mentioned, if you are flying with just two, it is easy to compensate.
Hmm, Vans spec for 260 hp engine is 201 mph at 75% with only 2200lbs wt. 197 at gross. My calculator says that is 195 hp. Either your airframe is super slick or you are making more power than you think you are.
pierre smith
Well Known Member
Yeah, I multiplied by .7 instead of .75.
Best,
Best,
twisted-wrench
Active Member
_________________________________________
Who is Andrew - AC KK? What company? Where? Contact info?
