Looking at the various discussions here about engine weights and cost, I gathered some numbers (below) for rough comparisons.
1) I looked at engines that could be bought new and completely assembled
2) Weights and costs are from "the internet", don't include exhaust systems, and are subject to a lot of variables.
3) To some extent, none of his matters. If you've got a particular type of flying in mind, then you may need a particular engine.
4) Costs are initial purchase price. Maintenance costs and resale value may also be important factors.
Edited to add: See later post for edited chart with corrections and additions.
Numbers:
Engine.................HP.....Cost ($)....Weight (lbs)...$ per HP.....Lb per HP
Lycoming O-360.........180....27,500.(1)...305.............153..........1.69
Rotax 912 ULS/S........100....19,437.......125.............194.........1.25
Aeromomentum AM13......100....10,495.(2)...201..(3)........105..........2.01
VW 2180cc.(4)...........76.....7,175.......167..............94.........2.20
VW 1835cc (5)...........60.....6,025.......165.............100.........2.75
VW 1835cc "basic",(6)...60.....4,750.......145..............80.........2.42
Harbor Freight670cc.....22.......584.(7)....97..............27..........4.38
"" + hub&bearing (8)....22.......734.......104..............33.........4.70
Notes
(1) Price through Van's direct purchase program. May be higher elsewhere?
(2) Price is for the Aeromomentum AM13 "low profile" version. The upright version is $8495
(3) Weight is for the AM13 engine, radiator, and coolant
(4) From Hummel engine site, includes dual ignition system, starter, alternator, carb, Force One bearing and prop hub
(5) As above, but simple shrink fit prop hub (no Force One bearing and hub)
(6) Hummel engine site: Single ignition, hand propped, no alternator, with carb
(7) With ubiquitous "20% off" coupon
(8) Estimated price and weight of additional bearing and prop hub: $150, 7 lbs.
Observations:
1) Mass production does a great job in lowering prices
2) Weight: The formula for a cylinder's included volume compared to its surface area is relentless. Bigger engines generally have more HP per lb. The Rotax stands out in this regard--but they sure charge for it!
My own very subjective opinion is that, for fun flying, there's slowly decreasing utility for each HP added after we get safely airborne. More HP is almost always more fun, but the first 25 HP that may get us airborne and enjoying the magic of flight surely gets us more "fun per HP" than the 25 HP difference between a 160 HP engine and a 185 HP engine. So, in that regard, the small industrial engines that provide that first, "highest utility" 20-25 hp at a lower absolute $$/HP are very impressive standouts--if we have a plane that can take advantage of it. Luckily, if our idea of minimalist fun flying requires 60-80 HP, there are still good $$/HP (and lb/HP) choices in that range, too.
Just some not-very-original rambling on this Sunday . . ..
1) I looked at engines that could be bought new and completely assembled
2) Weights and costs are from "the internet", don't include exhaust systems, and are subject to a lot of variables.
3) To some extent, none of his matters. If you've got a particular type of flying in mind, then you may need a particular engine.
4) Costs are initial purchase price. Maintenance costs and resale value may also be important factors.
Edited to add: See later post for edited chart with corrections and additions.
Numbers:
Engine.................HP.....Cost ($)....Weight (lbs)...$ per HP.....Lb per HP
Lycoming O-360.........180....27,500.(1)...305.............153..........1.69
Rotax 912 ULS/S........100....19,437.......125.............194.........1.25
Aeromomentum AM13......100....10,495.(2)...201..(3)........105..........2.01
VW 2180cc.(4)...........76.....7,175.......167..............94.........2.20
VW 1835cc (5)...........60.....6,025.......165.............100.........2.75
VW 1835cc "basic",(6)...60.....4,750.......145..............80.........2.42
Harbor Freight670cc.....22.......584.(7)....97..............27..........4.38
"" + hub&bearing (8)....22.......734.......104..............33.........4.70
Notes
(1) Price through Van's direct purchase program. May be higher elsewhere?
(2) Price is for the Aeromomentum AM13 "low profile" version. The upright version is $8495
(3) Weight is for the AM13 engine, radiator, and coolant
(4) From Hummel engine site, includes dual ignition system, starter, alternator, carb, Force One bearing and prop hub
(5) As above, but simple shrink fit prop hub (no Force One bearing and hub)
(6) Hummel engine site: Single ignition, hand propped, no alternator, with carb
(7) With ubiquitous "20% off" coupon
(8) Estimated price and weight of additional bearing and prop hub: $150, 7 lbs.
Observations:
1) Mass production does a great job in lowering prices
2) Weight: The formula for a cylinder's included volume compared to its surface area is relentless. Bigger engines generally have more HP per lb. The Rotax stands out in this regard--but they sure charge for it!
My own very subjective opinion is that, for fun flying, there's slowly decreasing utility for each HP added after we get safely airborne. More HP is almost always more fun, but the first 25 HP that may get us airborne and enjoying the magic of flight surely gets us more "fun per HP" than the 25 HP difference between a 160 HP engine and a 185 HP engine. So, in that regard, the small industrial engines that provide that first, "highest utility" 20-25 hp at a lower absolute $$/HP are very impressive standouts--if we have a plane that can take advantage of it. Luckily, if our idea of minimalist fun flying requires 60-80 HP, there are still good $$/HP (and lb/HP) choices in that range, too.
Just some not-very-original rambling on this Sunday . . ..
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