Hello all,
Warning : long post !
I am a newbie in the aviation world. I don't claim to have knowledge on anything. Just searching and learning. I dream that one day i will fly my OpenEz.
I have been investigating my engine options and narrowed down my choices to the following :
Rotax 914
Pros :
Light
Supercharged
Certification (not that i would get the certified model)
Not bad price
Cons:
Weak (115HP) (also low diplacement -> low torque)
Not cheap either (with the same money more powerful alternatives exist)
Never installed in an OpenEZ (or LongEz) as far as i know
Subaru EJ25 conversion
Pros :
Power! (160HP - 200HP depending who you ask, stock is 168HP)
Cheap (found one for 900 US$ in almost new condition)
Has been used before
Redundant ECU for ignition and EFI available
Reliability more or less proven
Cons:
single spark plug, single injector per cylinder
time to implement & trouble shoot unknown but probably long
not exactly lightweight ... (compared to the standard O-235)
Subaru EG33 conversion
Pros :
Power !!!!!! (250-300HP easy, stock is 256HP)
Cheap (found one for 650 US$ in rebuildable condition)
Has been used before
Reliability more or less proven
Cons:
single spark plug, single injector per cylinder
Dangerously powerful for the OpenEz ...
time to implement & trouble shoot unknown but probably long
not exactly lightweight ... (compared to the standard O-235 or O-320)
MAZDA Renesis Conversion
Pros :
Power ! (190HP - 220 HP stock is 192HP for the four port, consensus is 200HP easy)
Cheap (found one for 1500 US$ in good working condition)
Has been used before
Reliability more or less proven
two sparks, two injectors per rotor
Redundant ECU for ignition and EFI available
Cons:
time to implement & trouble shoot unknown but probably long
not exactly lightweight ... (compared to the standard O-235)
HONDA F22B DOHC / H23A
Pros:
Power ! (150HP - stock 150HP not easy to go for more without extensive modification)
Cheap (found one for 400 US$ in working condition)
Superior Honda Engineering
Relatively low cosumption
Closed deck block (Very stong, only valid for F22B though)
Cons:
Never used before
Unproven (although cam100 & cam125 have good name but not the same engine)
time to implement & trouble shoot unknown but probably long
not exactly lightweight ... (compared to the standard O-235)
HONDA H22A VTEC
Pros:
Power ! (180HP - stock is 200HP but at 6800 RPM. 180HP is possible at lower and safer RPM)
Cheap (found one for 1000 US$ in good working condition)
Superior Honda Engineering
Relatively low cosumption for the output
VTEC (more torque and HP at lower rpm band, i wouldn't be surprised if it would cruise more economically than all the others)
Cons:
Never used before
Unproven (although cam100 & cam125 have good name but not the same engine)
time to implement & trouble shoot unknown but probably long
not exactly lightweight ... (compared to the standard O-235)
Estimated installed prices +/-:
Rotax 914: 13000 Euro / 19500 US$ (Quote from local dealer for all i need)
Subaru EJ25 : 7000 Euro / 10500 US$ (engine, rebuild service, mount, reduction gear, ECU)
Subaru EG33 : 9000 Euro / 13500 US$(engine, rebuild service, mount, reduction gear, ECU)
MAZDA Renesis : 8000 Euro / 12000 US$(engine, rebuild service, seals, mount, reduction gear, ECU)
HONDA F22B / H23A : 7500 Euro / 11250 US$(engine, rebuild service, mount, reduction gear, ECU)
HONDA H22A VTEC : 7500 Euro / 11250 US$(engine, rebuild service, mount, reduction gear, ECU)
Lycomings are not present in my options because a rebuilt IO-320 engine in my country (Greece) was quoted to me at 20000 Euro (30000 US$ !!!) by local distributor, which is out of my reach.
Easiest to install and lightest is the Rotax but it is expensive compared to the others. Also most runways are short (1500ft +/-) here and the relatively low HP could cause trouble.
EJ25 is a good compromise but i am a bit skeptical as far as the weight is concerned. (anyone know what is the installed weight for this ?)
EG33 is more or less out of the question . The HP is dangerous. Only included because it is cheap. Won't use it ...
Renesis is good but heavy. Cast iron parts raise the weight. (maybe i should wait for the all aluminum 16x ...) Also the consumption is high compared to the others (epecialy the Hondas)
The Hondas are interesting with lower weight than the others and very good power / consumption ratio But they are a venture into the unknown . Will they fit ? Are there reliable ECUs ? A lot of unknowns here. On the other hand the experiment has its joys ...
My aim is the following :
175 Kts Cruise at 9000ft +/- with the lowest possible fuel consumption and
the lowest empty weight possible.
I think that the cruising speed can be attained by all these engines. the weight might prove problematic though.
Country limit for 2 seat homebuilds 550kg = 1212lbs gross, so i theoretically aim at weight of 363kgs = 880lbs without pilot passenger and fuel (is that doable ? i know original LongEz was 760 lbs +/-).
Any thoughts / advice on these ? Something i missed ? Does anyone have installed weight or long block weight data on these ? (Apart from Rotax,
i get conflicting numbers from the web ...) What would you choose ? Why ?