Engines, aircraft vs converted

Viewing a recent thread where an engine failed and caused an unscheduled landing, I did not want to hijack the thread.
But I hate to say this...but I do not know particulars about certified aircraft engines. I have been an A&P for 22 years but have always worked on turbine aircraft..
So. Looking at Barnstormers.com I have noticed that a used lycoming is a whole lot less than a rotax 912. I have seen from 0-235 to 0-320 for less than $10k, so what are the pros and cons of using a USED lycoming or Continental on a 2 place pusher gyro?
I know that Vance has had great success as well as a few others.

I have a CAM100 converted Honda civic engine, supposed to be around 115HP @230lbs. But the replacement belt drive setup (I do not need one, thank goodness) is almost $9k !! I am just using this as an example, I do not know what a converted Subaru, or other costs.

Just throwing this out there, if I was to be starting a new 2 place project
and could pick up a used aircraft engine for lets say $7k what would I look for? HP weight etc.

I totally agree with you. I always ask myself what's my life worth then go for maybe a little more money but aircraft grade engine. If I built a 2 place gyro of my own design I might go for an 0360. It does not weight much more then an 0320 but has 30 more HP.

Hi Scott!!
The only problems I've heard of for aircraft engines are that they over heat on pushers.
Yet the 3 I've seen flying have no problem and have no extra cowling to provide extra cooling.

The other fact more than a problem is that they are heaver than a rotax and use more fuel per hour burn.

PRA31 is building a two-place Genesis G2sa with a Lyc O320 and Nicolas has to re-design the G2sa specifically for the O320 and has already explained that it will not yank and bank as well with more mass.
But it's a training cross-country machine so that's not what it's for.
As far as fuel burn our Cherokee 180 has a special exhaust with a 337 that increases climb performance while reducing the fuel burn from 10.4 to as low as 7.4 with low weight in the plane.

We'll be using this same exhaust and as the G2sa is so much lighter I expect with my low weight I'll be running at 40% or 50% power further reducing the fuel rate per hour yet the power will be there to fly and train the heaver pilots.

How do the the HP and weight compare to a converted subaru, or other engine?

scottessex said:

.. so what are the pros and cons of using a USED lycoming or Continental on a 2 place pusher gyro?

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I interpret 3 cons only, weight, weight and weight. Compared to other choices out there, the power to weight ratio of the complete engine installation is not as favourable as with the modern engine choices now available.

Is that $7K high time Lycosaurus going to give you the full HP it was originally rated at?

Probably works well in the larger sized gyro's, I doubt if you can squeeze it into the smaller compact 2-seaters.

Simply my 2-cents worth.

Cheers,

Francois

Looking up dry weight no options a 0360 Lycoming is about 260lbs 180 horse power. A Rotax 912 is about 150lbs at 100horse power.


The big advantage is parts are everywhere and so is a mechanic.

...and as reliable as hammers.
It's a rare Lycoming that doesn't make its TBO in normal use, and then again after rebuild, and again, and . . .

And if a certified one you have documentation so no guessing games about where it came from & where it's been.

By the time you add in the weight of a redrive & cooling system I'd bet an ancient Lycoming O320 or 360 stacks up pretty well against a converted auto engine in the same power class.

I guess the 0290 was the ground power unit engine?

Memory!!!

Memory!!!

scottessex said:

How do the the HP and weight compare to a converted subaru, or other engine?

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Scott, if my memory serves me correct a 120 hp ej-20 with gearbox, exhaust and radiator was 110kg (242 lbs.) We weighed one for a guy building a fixed wing and was comparing various power plants.

Aussie Paul.

Using Texas' figures the power to weight ratios are similar at 1.44lbs/hp for the Lycoming and 1.5 for the Rotax. The shrouding for cooling the Lycoming pusher may be a little involved.

The Lycoming though is in a different power class. It can easily power a 2 seater whereas a 912S requires a light 2 seater. My experience with the 912S powered Xenon was of an underpowered gyro.

Higher specific fuel consumption for the Lycoming would be an issue for long range mission requirements which is usually not the case with gyros.

I would go for the Lycoming and build your gyro to suit the engine leaving clearance to swing a 72" prop and avoid inefficient small diameter wide chord or multi blade props.

Dino

There are several styles of eyebrows (cooling shrouds) out there that work fine, all use ram-air with down-flow. Vance uses free-air. The TwinStarr uses an interesting up-flow chamber with prop suction. They’re getting the coolest temps that I’m aware of on a pusher. I plan to try this on my Continental A-75 pusher. My temps are well in the green with my eyebrows but I’d like to drop another 50 degrees. I push this engine very hard (harder than you are supposed to.).

BTW, after considerable research I've switched to Phillips 20-50 with Cam Guard additive.

scottessex said:

How do the the HP and weight compare to a converted subaru, or other engine?

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I investigated the weight to horse power ratios of different engines when I first came to this site a few years ago.
Don't remember the exact weights and ratios I researched then.

But as I remember it when you add the extra weight of the radiator and coolant, the reduction drive the aircraft engine weighed less or about the same.

Also you can not beat it for 2000 hours of dependability and as JR said then rebuild it again and again they are just about as dependable as a hammer.

The last thing to compare is the cost.
If you rebuild a car engine for aircraft use and add the cost of the radiator and reduction drive I'll bet it cost as much or more than a used O320 for $5K to $8K.

PRA31's Genesis G2sa will cost us about $40,000.00 (with us assigning $6,000.00 for the clubs Hollmann O320) with a glass cockpit w/GPS, radio, Mode C transponder, Compass card, and clock with a 150 HP engine.

Compare the $40,000.00 with the European two-place open cockpit using Rotax 514 cost with less HP and there is no comparison in my evaluation.

Lycoming in tractor configuration might be worth considering as prop clearance and firewall forward from an existing design would simplify things.

Dino

Or you guys could just use a Corvair Conversion, 4 cycle, air cooled, 6 cylinder, 190cid(3,100cc), at 212-217lb producing 120HP@3, 200 peak and [email protected] Continuous.

Here is the link http://www.flycorvair.com/index.html

Dan

This same battle is going on in the airboat forum.
The recent introduction of the GM ECOtec into the airboat world,
has got everyone talking. The turbocharged 1.8 on my buddies boat,
is now making 330 hp. with his current 'tune'. He is burning around 4 gph.
My ECOtec is normally aspirated 190hp, and burning 5.4 gph. I'm swinging a 74" Whirlwind Whispertip. The guys are realizing the old aircraft technology, is being replaced with effecient, reliable engines.

Anthony Spagnoletti had a beautiful 2 place Air Command powered by the ECOtec,
and told me he seldom used 50% of the available power. There are pics on forum.

Here are some developments on the water cooled 4 stroke aviation specific engine front from MW Fly per a recent EAA announcement. Looks to be right in the weight and power class to catch gyronauts attention

http://www.eaa.org/news/2013/2013-01-31_mw-fly-develops-B25R.asp

Earthboundmisft said:

is now making 330 hp. with his current 'tune'. He is burning around 4 gph.

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If he's really burning 4 gallons an hour he's only using about 60 hp of it though.

Sure, these newer engines can be more efficient - but we're talking maybe 10% difference.

danmcgee said:

Or you guys could just use a Corvair Conversion, 4 cycle, air cooled, 6 cylinder, 190cid(3,100cc), at 212-217lb producing 120HP@3, 200 peak and [email protected] Continuous.

Here is the link http://www.flycorvair.com/index.html

Dan

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I would stay far, far away from that Chevvy mess. There's another word for it as to be used on a gyro: Junk