Subaru's new 40hp industrial engine

HomeBuiltAirplanes.com

Help Support HomeBuiltAirplanes.com:

Cy V

Well-Known Member
Joined
Jul 1, 2008
Messages
450
Location
Virginia

Dan Thomas

Well-Known Member
Joined
Sep 17, 2008
Messages
5,797
But at what weight?
I did a bit of Googling but can't find any weight or RPM specs. It sure looks a lot like the Generac from Briggs and Stratton, but I bet it's a better engine.

Dan
 

cheapracer

Well-Known Member
Log Member
Joined
Sep 8, 2013
Messages
6,296
Location
Australian
These little Subaru engines (sold as "Robin" in the US) have a good reputation.
In Australia for example they have a racing dirt Kart class and the rules are these type of industrial engines can only be used and the Robin rules by far.
 

Cy V

Well-Known Member
Joined
Jul 1, 2008
Messages
450
Location
Virginia
It sure looks a lot like the Generac from Briggs and Stratton, but I bet it's a better engine.
I'd say it's a better engine, too. I'm almost 40 now and my parents have driven Subaru cars ever since I was a little kid. The engines in those cars are about as close to bullet-proof as you can possibly get. Right now my mother is driving around in a Subaru Forester with over 150,000 miles on it. The little engine in her car keeps right on going.
 
N

Niels Abildgaard

What kind of aircraft can use such an engine and what prop diameter will be suitable?Am asking because it will be fun to scheme a single cylinder inverted and ungeared engine that will be better on all counts.I have driven a 250 ccm MZ bike for 80000km and it only stopped once unscheduled (in pouring rain )and the local wise guy sprayed silicone on the sparkplug-cable and the caravane drove on.A single cylinder is less stopprone than a twin.MZ 008 1.jpg
 

saini flyer

Well-Known Member
Joined
Mar 12, 2010
Messages
478
Location
Dallas, TX
How is the horsepower for industrial engines rated, ie., continuous or peak?
Is the Subaru 40HP continuous HP for the engine?
The generac at "32HP continuous/38HP peak" has been modified by Valley Engineering for upto 50HP peak and they may do the same for this one too. Is the Subaru fuel injected?
I'd say it's a better engine, too. I'm almost 40 now and my parents have driven Subaru cars ever since I was a little kid. The engines in those cars are about as close to bullet-proof as you can possibly get. Right now my mother is driving around in a Subaru Forester with over 150,000 miles on it. The little engine in her car keeps right on going.
 

Cy V

Well-Known Member
Joined
Jul 1, 2008
Messages
450
Location
Virginia
Saini Flyer: I made an assumption on the 40HP Subaru engine having fuel injection. The article doesn't specifically mention that it does. I made this assumption because the model right below it does have fuel injection. I didn't think it made sense for them to suddenly switch to a carburetor on a more powerful unit.
 

Rienk

Well-Known Member
Joined
Oct 11, 2008
Messages
1,366
Location
Santa Maria, CA (SMX)
I am not a gambling man, but I would bet 10:1 that this is the exact same block as both the Generac and the B&S. Most people don't realize that the design and castings are actually from Daihatsu. The difference between them is the crank (Generac wins) and the stock carbs (B&S usually wins).This Subaru looks like an exact clone of the Generac, though if it has EFI, that is a huge plus (I hope so, but I doubt it - the intake manifold looks like it's mated to a carb). All of these engines can easily put out 40hp at the same rpms. Valley Engineering is getting their horsepower primarily from revs; these engines are also very popular on mini airboats, which torque them up to 4500 rpm (ported, etc) and get 65hp out of them... but if you want to go conservative and somewhat stock, 4000 rpm is about max for peak, and 3600 should be max continuous.I'm looking forward to learning more about it - almost guaranteed to work with our redrive and other modifications!
 

Vigilant1

Well-Known Member
Lifetime Supporter
Joined
Jan 24, 2011
Messages
5,993
Location
US
Would make a sweet little twin two-place. That way you could test the engines for reliability.
I dunno. I'm trying to imagine what the plane might look like that could have two people aboard, one dead engine (with its weight), and could still climb safely (with the drag of a stopped or windmilling prop) on 40-60 HP.

A twin that can't perform adequately on one engine is less safe than a single. As the joke went concerning operational O-2s in use in Vietnam, : "The second engine is just to get you to the crash site."
 

saini flyer

Well-Known Member
Joined
Mar 12, 2010
Messages
478
Location
Dallas, TX
Henryk,
For all practical purposes the weight can be assumed to be that of the stock Generac if no EFI is used. You can look at Valley for a turnkey that Duncan has at about 120 lbs at 48-50HP including everything (exhaust+redrive+prop+hub etc too!)

I am really interested in the EFI side as that will be huge even at a slight cost penalty and the other Subaru has EFI so I am keeping my fingers crossed but I wont put my money on it.
-I cant finde the weight of SUBARU EH99...?
 
Top