SMA Engines - Jet A for GA
Join Date: Jun 2003
Location: EuroGA.org
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I don't know the current figure and it would depend on the plane, but when I asked them at N Weald earlier this year, it was pretty obvious one had to be flying 500+ hrs/year to make it worth doing.
I suspect very few people will retrofit, but in a new plane (e.g. a Diamond DA40) it's an entirely different proposition.
I suspect very few people will retrofit, but in a new plane (e.g. a Diamond DA40) it's an entirely different proposition.
Join Date: Dec 2002
Location: Crowthorne
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For a retro fit, the SMA is a very bad choice. Even a new fit is suspect.
Over priced and over weight, i.e lower power to weight ratio than an IO360, the design concept is wrong. But what do you expect from an F1 4 stroke engine design team. Had to build it heavey due to all the big pistons and torque reversals.
The best diesels are 2 strokes, with external blowers.
Give smoother power delivery and many other advantages.
The Delta Hawk V4 will be better, cheaper and lighter at a third the cost.
In the UK, the 200hp model will save £60,000 in fuel and service costs over 2000 hours against a Lycoming 360.
The Zoche 300hp 8 cylinder radial would be the best, if it ever happens, even derated to 200 hp it still weighs the same as an IO360. Will be as smooth as silk with 8 power pulses per rev against 2/rev from a 4 cylinder 4 stroke and the prop drives the engine for 30% of the time per rev also.
So I would put the SMA in the catogary of brut engineering over good engineering sense.
The Thierlet is a four stroke but has a reduction gear box and harmonic damper, because of the torque reversal problems, this has to be replaced every 1000 hours. Fast to market but!
2 Stroke Marine diesels have been around a very along time, so a well proven concept, infact with the fuel sprayed in at the top of compression, air spill through is not a problem as with 2 stroke petrol engines, infact it cools the cylinder internaly. Thats one of the reasons SMA had cooling problems with the 4 stroke design.
Over priced and over weight, i.e lower power to weight ratio than an IO360, the design concept is wrong. But what do you expect from an F1 4 stroke engine design team. Had to build it heavey due to all the big pistons and torque reversals.
The best diesels are 2 strokes, with external blowers.
Give smoother power delivery and many other advantages.
The Delta Hawk V4 will be better, cheaper and lighter at a third the cost.
In the UK, the 200hp model will save £60,000 in fuel and service costs over 2000 hours against a Lycoming 360.
The Zoche 300hp 8 cylinder radial would be the best, if it ever happens, even derated to 200 hp it still weighs the same as an IO360. Will be as smooth as silk with 8 power pulses per rev against 2/rev from a 4 cylinder 4 stroke and the prop drives the engine for 30% of the time per rev also.
So I would put the SMA in the catogary of brut engineering over good engineering sense.
The Thierlet is a four stroke but has a reduction gear box and harmonic damper, because of the torque reversal problems, this has to be replaced every 1000 hours. Fast to market but!
2 Stroke Marine diesels have been around a very along time, so a well proven concept, infact with the fuel sprayed in at the top of compression, air spill through is not a problem as with 2 stroke petrol engines, infact it cools the cylinder internaly. Thats one of the reasons SMA had cooling problems with the 4 stroke design.
