Chev V8 sweetness

[the4ork]

i love those dragonfly's are those kits still available?

[rv6ejguy]

Originally Posted by the4ork

i love those dragonfly's are those kits still available?

I'm not sure. I have two friends with turbocharged EJ25 powered ones and they really move at altitude.

[rtry9a]

I know several folks who built Dragonflies- VW powered. The kit looks like it is mostly a box of foam sheets that you have to shape/ glue/ glass together, and a set of plans.

The reports are that they are very efficient planes with minimal power (150 mph w/ 60 hp) but slow climbers at normal density altitudes around here.

re Chevy V-8: I doubt that any long throw auto V-8 conversion will last very long at high rpm under full loads. A short throw, big-bore might work, but would likely be excessively heavy. I believe the better high hp solution is probably a 3-rotor wankel, especially if turbocharged. 400-500 hp should be no problem at all, and they would be significantly more durable and reliable, not to mention, much lighter. IMHO, in the IO-360 range, the OEM Wankels are near equals in power:wt; but in larger apps (compared to I-540's+), the prepared Wankels really shine.

[osxuser]

I think the Chevy is actually viable, considering that they are getting a reliable 400ish HP from them with car tunes, if you want a 300HP one for an RV 10 it should be pretty doable. As for competing with a turbine... that remains to be seen.

[Mike S]

Originally Posted by the4ork

i love those dragonfly's are those kits still available?

I have a Dragonfly project that is available. 90% done, only 90% left to do.

They are really great planes, but my wife in not interested in it, she wants the -10 done.

Contact me for more info.

Cell 530-417-1124, or you can PM or e-mail.

[rv6ejguy]

Originally Posted by rtry9a

re Chevy V-8: I doubt that any long throw auto V-8 conversion will last very long at high rpm under full loads. A short throw, big-bore might work, but would likely be excessively heavy. I believe the better high hp solution is probably a 3-rotor wankel, especially if turbocharged. 400-500 hp should be no problem at all, and they would be significantly more durable and reliable, not to mention, much lighter. IMHO, in the IO-360 range, the OEM Wankels are near equals in power:wt; but in larger apps (compared to I-540's+), the prepared Wankels really shine.

Bud Warren has over 700 hours now on his 383 Chev and it is still going strong. Gary Spencer's 360 Ford has around 500 and several LS powered aircraft notably Robinson's have several hundred also on theirs. Not wearing out or failing.

These engines are not being run at high rpm- around 3800-4500 for takeoff and mid to low 3000s for cruise. No harder than a drive on the Autobahn or AutoStrada in Europe at 150-200 KPH-daily use over there.

The aluminum block/ heads available today make these engine more competitive in the weight department today.

The peripheral port 13B Wankels and turbocharged ones running high hp have not demonstrated long life in other applications. Even the Renesis has had checkered reliability and serious oil consumption problems in stock form. I believe that an almost stock 20B is a more suitable engine for RV10 class airframes. Wankels have serious heat concerns when combined with turbocharging, especially at high boost which is why you never saw them raced in that form except in showroom stock. Exhaust system and turbocharger reliability is a question mark at this time due to the high EGTs.

Street ported, running below 6000rpm with all the well known cooling and apex seal mods done and these are reliable for aviation use as proven by many to date.

[TSwezey]

************************************************** ******************************
** Report created 10/19/2007 Record 1 **
************************************************** ******************************

IDENTIFICATION
Regis#: 901RC Make/Model: EXP Description: 350HP
Date: 10/18/2007 Time: 2251

Event Type: Incident Highest Injury: Minor Mid Air: N Missing: N
Damage: Unknown

LOCATION
City: MONTGOMERY State: TX Country: US

DESCRIPTION
AIRCRAFT CAUGHT FIRE, LANDED OFF AIRPORT, MONTGOMERY COUNTY, TX.

INJURY DATA Total Fatal: 0
# Crew: 1 Fat: 0 Ser: 0 Min: 1 Unk:
# Pass: 2 Fat: 0 Ser: 0 Min: 0 Unk:
# Grnd: Fat: 0 Ser: 0 Min: 0 Unk:

WEATHER: VFR

OTHER DATA
Activity: Unknown Phase: Unknown Operation: OTHER


FAA FSDO: HOUSTON, TX (SW09) Entry date: 10/19/2007

[Yukon]

God bless you alternative guys who want to take this kind of risk.

[Pirkka]

Originally Posted by Yukon

God bless you alternative guys who want to take this kind of risk.

Are you considering taking risk when not going for certified aircraft? Alternative engine is as experimental as RV, although RV has been tested more so far by users.

[gmcjetpilot]

Like Yukon said God bless those who experiment and take the risk of test pilot. Despite aluminum heads and block, weight is an issue. However for the right airframe, like a single seat WWII fighter replica, pretty cool.

Despite the sticker HP Chevy advertises, you will not fly around at 6,000 engine RPM's and rated HP. Like a Lycoming you fly typically at 75% or less power but more than ever, with a Chevy V8 you'll need to operate well under 75% power to get any reliability or fuel econ.

To go down the freeway in a car takes, what, 35 hp to 90 hp? (depends on vehicle weight, drag and grade) Despite the +300 hp rating, these engines (LS1) are designed to see peak HP ratings only intermittently (as you wind out the gears, not for minutes continuously). The gear box/PSRU is another story. Obviously you can get along pretty good on say 50% of peek HP for these V8's. However that is less HP than the continuous or 75% HP a 540 Lyc can give which weighs less. Frankly a Lyc can fly 100% all day as long as CHT and oil temp are with in limits. A Chevy V8 would not last long at 100% power.

Fuel burn? No advantage with these big V8's. This is where I say, No free Lunch. Now there are some cool advantages of a big V8, sound being one.

Cost? Really no savings when all cost are added up. The promise of cheap flying is seductive but illusive. The promise of cheap high performance flying is just a fantasy.

Sound? Awwsome, but so is a big radial or RR Merlin. I can't afford any of them either, so I'm going to put a sound track of engine sounds on my iPod and play it back through the intercom. (got to figure a way to make the recorded engine sounds change with the throttle?)

(Sorry to repeat my opinion; however these threads come up time and again and new folks reading this may be distracted from building, spending time chasing a dream. For very few builders this is a good path. It takes a special person to make large deviations from the plans. For most sticking with the plans and a Lyc engine is the path of least resistance with known performance and economics. Not least of which, ease of building is assured with the Lyc. If you are a mad scientist type, you know who you are, alternatives can be great. Most knowledgeable experience alternative engine builder/owner/pilots say pretty much the same thing. You want to tinker, alternative engines are great. If you want to finish and go fly, get a Lycoming.)