There is good reason for the impeccable reputation
DA engines enjoy. All that "pretty" is reflected in
high end machining throughout.
Text, photos and video by Tom Hintz
Flight video by – Mike Basmajian
Posted – 7-18-2018
When the electric start on my L-4 Grasshopper engine began failing, I decided to cut my losses, jerk that engine and replace it with my DA-35 Gas Engine. Aside from going to Desert Aircraft Engine, the best thing about this swap is that it was essentially a bolt up deal. The throttle linkage had to be tweaked a tiny bit and the cowl cut some for the Pitts style muffler on the DA-35 Gas Engine but other than that, the installation was painless.
The DA-35 Gas Engine is as gorgeous looking as it is a powerhouse for this displacement. Desert Aircraft Engines have always been known for their super-precise CNC machining and high-end 7075 aluminum alloy used for the crankcase. That precision machining on the outside is reflected in the ultra-precise tolerances and high-end components used throughout these engines.
The DA-35 Gas Engine has a displacement of 2.14 ci (35 cc) and weighs a trim 2.06 lbs (935 kilos), almost half a pound lighter than the EME35 it replaced. With the included stand-offs the prop washer to firewall dimension is 6.35” (161mm) which fits most planes in this class. On my ¼-scale L4 Grasshopper I had to add ¼” spacers under the stand-offs to fit the installed cowl length properly. That is because the cowl was cut for the original engine.
The DA-35 Gas Engine comes equipped with a Walbro carb, universally regarded as the best there is. The DA-35 Gas Engine uses a four-petal reed valve to control the precise fuel-air mixture flow to the cylinder. It should not be surprising that combining the best carb and best engine on the planet adds up to a best-in-class reliable, easy to fly package.
Desert Aircraft’s very trick electronic ignition is included and runs on 4.8 to 7.2-volt power. Built into this ignition is an auto advance that makes throttle transitions exceptionally consistent while smoothing the engine throughout the RPM range of 1,500 to 8,200. DA has a “Safe Start” feature built into this ignition that helps prevent kickbacks. You must flip the engine aggressively for it to issue a spark to fire the engine. This all adds up to remarkably easy starting engines, now and for many years to come. Unlike most model engine ignition systems, the DA version can be serviced if you happen to fail to miss the Earth resulting in a premature end to a flight.
A genuine WalBro carb comes on this engine, as you
would expect
The DA-35 Gas Engine carries prop recommendations as follows: 2-blade props - 19x10, 20x8, 20x9 and in 3-blade props - 18x10 and 19x11 Narrow. All per Desert Aircraft literature. I have been using an Xoar 19 X10 WWII prop on the L-4 Grasshopper and that seems to be a good combination for my style of flying. I also flew the L-4 Grasshopper with a Vess 20B which falls into the 20 by 8 range and the DA-35 Gas Engine seemed to like that as well.
As you might suspect, folks that build an engine like this are proud of their efforts and confident in their long-term performance and reliability. Desert Aircraft covers their engines with a 3-year warranty. Plus, they offer world-class service whether you need crash damage investigated/repaired or just a freshening after who-knows-how-many flight hours it takes to require rebuilding. Finding people who needed warranty service on these engines is surprisingly rare. I know it is bound to happen sooner or later as they make a huge number of these engines and they seem to be flying at all model airfields.
There is something about starting a Desert Aircraft engine in a prized model that makes you feel like you have arrived. You’re flying with the “cool kids” so to speak. More importantly to me is the confidence I have in this engine. It’s the best insurance I know of for a plane I’d like to fly for years to come. You should also know that if you mess up and dork a Desert Aircraft engine into the ground the mood at the flying field can change dramatically. There will likely be much gnashing of the teeth in the pit area over such an indiscretion. It’s a Desert Aircraft Engine, what could you have been thinking?
Prepping a Desert Aircraft engine for flight is seldom complicated. They come with the carb adjusted very close to, if not perfect. I did have to tweak the DA-35 Gas Engine two or three screwdriver blade widths (richer) on the idle, probably as much to appease myself than to correct anything within the cowl environment.
The DA-35 Gas Engine has proven to be easy starting and smooth running. The idle, after initial setting in the L-4 Grasshopper airframe is, so far, perfect. I do touch and go’s constantly, usually flying down the field wide open then chopping the throttle to idle as I turn back to the runway. I have yet to have the DA-35 Gas Engine hiccup, cough or choke when I make this sudden throttle change. Even after a long, slow glide to the runway the throttle response is quick when I need a small squirt of power or go to full power to fight off a gust of wind. With a Desert Aircraft engine, I learn to be confident in its response. With lower-priced engines I am more apt to learn when to be careful with throttle changes to avoid another dead stick landing.
Saying that I am happy with a Desert Aircraft engine these days is hardly news worthy. That is a nearly universal feeling amongst Desert Aircraft Engine owners in the RC community. However, I remain impressed whenever I start or fly a Desert Aircraft engine because of all the traditional qualities and features.
With a street price of $449.00 (7-11-2018) the DA-35 Gas Engine is priced closer to many of its “competitors” than you might suspect. My RC budget suffers from the same frailties as anyone else’s. However, paying the difference to equip a plane with a Desert Aircraft engine still makes the best long-term fiscal sense, especially if I install it in a plane I like a lot. And, that doesn’t consider my peace of mind instilled by having a DA-35 Gas Engine up there hauling my L-4 Grasshopper around the sky and idling down reliably time after time during my touch and go fiestas.
There appears to be no argument that the quality of materials and workmanship mean Desert Aircraft engines need service less than virtually all other brands out there. Certainly, other brands are popular, I have other brand engines in some of my planes and like them. Would I trade another brand engine for a Desert Aircraft power-plant? I think Desert Aircraft engines are better, contrary to the opinion of other brand marketing types. They can hate me all they want, I’ll be out at the flying field, more often than not, flying one of my Desert Aircraft engines.
Visit the DA-35 Gas Engine product page – Click Here
L-4 Grasshopper "Re-Birth" - Click Here
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