New Eggenfellner Performance Numbers
 

Jan has just posted the results of testing the new H6, belt drive, James cowling and 4 blade carbon prop on Tom Moore's RV7A. 175 knots TAS on 8.9 gals./hr. at 8500 feet, 2100 prop rpm and 21 inches MP. I think this is pretty impressive. :)

http://www.eggenfellneraircraft.com/...mance Page.htm

Good info
 

Engine 5376 RPM! Hooche Moma! 201 mph at 8.9 gal/hr is not bad.

I guess a typical cruise mode will not be at full throttle:
prop 1800 rpm
eng 4608 rpm
eng 21.0 map
eng 8.2 FF
tas 190 mph

To put that into perspective a 160HP RV-7A at 75% cruises at 190 mph.

Fuel flow should be around 8.5 ga/hr at 2,400 rpm (ref. Lyc diagram IO-320 B,D part throttle fuel consumption). So the H6 is getting 0.30 gal/hr better fuel econ from my rough numbers @ 190 mph.

A Sam James cowl on the Lyc, would go faster (or burn less fuel) than Van's stock cowl. Assume max gain for SJ cowl on a Lyc RV-7A is 8 mph, in cruise say 4 mph. The Lyc with electronic ignition gets you 4% decrease in fuel flow, down to 8.1 gal/hr, plus a mph or two. The SJ cowl would be a notch up on speed (4 mph) and efficency, but with the stock numbers the H6 compares favorable with the 160 HP Lyc in cruise.

However interestingly enough at full RPM, 5376, even if you would not fly that way all the time the 201 mph at 8.9 gal/hr is like a 180 HP Lyc at 75% power at 9.2 gal/hr. Interesting. Again this is a stock Lyc and cowl. It appears the H6 is producing about what a 180HP Lyc is making and slightly better spacific consumption at full RPM. Again a EI would give the Lyc the same FF and the SJ cowl gets you a slight speed edge.


What does that mean? The new drive is doing good from these prelim numbers. :-) It looks like the H6 is a true 180 HP engine (equivalent Lyc at the prop). It also looks like it is getting similar speed and fuel burn. In fact the burn to stock Lyc numbers from charts is slightly better. However with EI and SJ cowl the Lyc will have a slight advantage in both speed and econ.

Good for Eggenfellner. The big question is would one want to cruise at 5376 RPM. Also weight was not reported but suspect it is hefty affecting stall speed, takeoff/landing dist and climb rate.

I would like to know the empty weight of the H6 set-up on the RV-7 with the new prop and reduction.

Good info thanks George

22.5 mpg at 201 mph
 

That is pretty impressive. 22.5 mpg at 201 mph. My car gets about 20 mpg at about 70 mph.

"QUESTION: How much does the firewall forward package weigh?

The H-6 engine has the same firewall forward weight as the IO-360. The total is 350 for the engine and 420 for the firewall complete package. Add 30 lb to this for a supercharged H-6 model."

http://www.eggenfellneraircraft.com/FAQ.htm

I was wondering also....

Thank you
 

I hear you Ward, however I have doubts. Why?

I asked Jan this and that was what he said, about the weight of a IO360. He also said the H6 weighed 40 lbs more than 2.5L, but in the same breath he acknowledged that 1140 lbs was a typical RV-7, 2.5L empty weight. The two don't jive.

If you look at the empty weight of Eggenfellner 4 cyl 2.5L installations, they already weigh the same or more (by quite a bit in some cases) than a IO360 (200HP). So I think the H6 is going to come in at least 40 lbs more than IO360's, since the 2.5L already weighs what IO360 RV's weigh.

If you go to Dan C's excellent W&B tabulation of finished RV's you will see that the eggenfellner (2.5L) RV's weight compares and even exceeds RV's with the heavy IO360. http://www.rvproject.com/wab/

That is the same conclusion I came to. One Egg/MT prop RV-7 weighed 1140 lb. Of two RV-7's and two RV-7A's with IO360's, their weight came in at 1103 to 1141 lbs.

Now take an extra 40 lb plus another 30 lbs for supercharged, that is quite a bit more. It will be interesting to get the actual empties. The supercharged version lets say will weigh 1210 lbs. That leaves 590 lbs for payload+fuel. That is under 400 lbs for pilot/pax + bags. Of course there is the time honored method of arbitrarily upping the max allowed gross. Dual aerobatics will be a bit of an issue. You can't fudge with that weight. G

Actual innovation
 

I think it is interesting to point out that Eggenfellner is trying to take an interesting and innovative tack in the small piston market, and that is the "slow" turning prop. Notice that max speed here is with the prop spinning at 2100. A nice cruise has the prop at 1700 or less.

I don't know how this will eventually work out, but I have to commend him for trying out this kind of fairly radical idea in our marketspace.

It would appear that all numbers are at WOT (21 inches) and that only rpm was varied via prop pitch. On an auto engine there is a significant change in hp with rpm. Bottom line here is that the new H6 configuration is competitive in speed and fuel flow to most O-360 powered -7As that I'm aware of. Anyone else doing over 175 knots TAS on less than 8.9 gallons hr. in real life?

Weight wise it would be interesting to know however this prop is at least 30 lbs. lighter than a Hartzell C/S.

?? don't you mean "any" engine (of the rotating variety)? hp=tq x rpm/5252


diesel Velocity. 6.7g/hr@180ktas. but that's another story. Jan is doing well with the H6.

I agree. SMA did this on their diesel using large MT prop (direct drive). The engine ran full power at 2300.

Any info on the specs of that prop on the Egg? I suspect he'd be even faster with large diameter 2-blade in the 76" range since tip speeds are not an issue at 2100. 80" would be ideal but ground clearance becomes a factor above 76".

Reality Check