ej207 turbo engine in -4 or rocket?

[the4ork]

I was thinking.... Tuners have gotten rather suprising #'s out of the WRX engines, I dont know what they weigh in at but I do know some ej motors have been used as I saw on sdsefi.com, but im unsure of which engines have been used, but would it be possible to pump out enough power to give a 540 a run for its money? Or at least match it in terms of performance?

[Mike S]

Originally Posted by the4ork

but would it be possible to pump out enough power to give a 540 a run for its money?

Yes.

But, why???

[the4ork]

yeah I did a search on it just a few minutes ago... Looks like more work, more wieght, less power, less reliable.... Sad.

But who's to sayyiu can't hop up a 360 or 540, they are around 8.5:1 compression factory right? Why not 10.5:1 or turbocharged with some custom forged pistons/rods and of course the manditory headwork that can be done, should u want more power....

I at least would like to do some headwork, friction coating on the internals and ceramic coated pistons, and heat dispersal coatings on the outside of the cyl's and heads all of which should hep keep the engine super efficient. I've done this to my vw turbodiesel engine with good results

[rv6ejguy]

Making more power than an IO-540 is childs play with even a 4 cylinder Subie, longevity at that hp level might be in question. Nothing like having some more cubic inches. A lightly turbocharged EG33 should provide power competitive with an IO-540 at low revs. I'm preparing just such an engine now for our RV10. The only internal mods are forged pistons- stock cams, rods, no head work. The rest of the engine appears very bulletproof- already has forged rods and forged nitrided crank from the factory plus massively thick castings.

Weight is very similar- long block is 250 lbs., Marcotte M-300 PSRU is 47, twin turbos with plumbing and intercoolers about 65, manifolds, injectors, TB etc. about 30, rad, scoop and coolant about 35.

I expect weight to be close to a wash using an MT prop.

The turbo might be cool in a Rocket at altitude with their higher limiting speeds but I don't think a Subie interests most of this crowd. If I were building a Rocket, I'd be seriously looking at an LS6- 380 lbs. for the long block and 405 hp stock. Only a bit heavier than the IO-540 but with easily 50 more hp at conservative rpms. Just over $5K brand new. I've got one on my shop floor right now...

Alternately an LS7 is slightly lighter having titanium rods and intake valves, sodium cooled exhausts and 505hp for about $14K.

[Mike S]

Ross, IIRC, you are using a 6 cylinder in your 10.

4ork was asking about a WRX engine, which I believe is a 4 cylinder.

Or, am I just plane confused??

Seems to me that to get a WRX up to the same power as a 540, it would be extremely complicate in the management concerns, and I wonder at the reliability issues when pushed this hard.

[the4ork]

Wrx motor is a 6 cyl

[Mike S]

Originally Posted by the4ork

Wrx motor is a 6 cyl

http://www.cars101.com/subaru/imprez...ew%20for%20WRX

Seems these folks disagree, Ross--------help us out here.

[rv6ejguy]

The STI engine is a 4 cylinder 2.5L turbo and puts out 300hp stock. Theoretically you could derate this engine to 250 or so by reducing boost and peak rpm to under 4500 rpm and retain reasonable longevity. These engines have some pretty good factory bits like piston squirters and sodium cooled exhaust valves. The factory turbo would have to go and be replaced by a more suitable unit for aviation use. You'd end up with a very lightweight package which might be nice for a modified -4.

How long would it last running at say 180hp in cruise? Probably long enough to get your money's worth before overhaul.

Yes, I'm using the 3.3L six which will be just loafin' in cruise at 3500-4000 rpm and 30 inches or so.

[Mike S]

Thanks Ross, re-reading my post, I noticed the link was to a 2004 model, glad it hasn't changed, I really look silly with egg on my face.

What is your 6 cylinder originally out of??? Only one I remember was from a 80s or 90s attempt at a sports car--------dont remember the name, 3 letters/initials IIRC, but sure had funny windows

[Randy]

I am flying with the STI engine in my RV7A and the more I fly it the more I like it. Eggenfellner only sold 25 of these in one batch and dropped them for the much simpler H6. I think this engine could be a really great RV engine if the package could have evolved a little more before Eggenfellner dropped it in favor of the H6.

Mine is supercharged rather than turbo and it works well.

It makes plently of power for an RV 4, 6, or 7, maybe a bit much for a 9. I am not sure about trying to compare a 150 cubic inch Subaru to a 540 cubic inch Lyc. Holy smokes, that leaves 390 cubic inches on the table. It is certainly capable of making a full 300 HP in stock form and as you can imagine, in the rally car racing they pump some amazing HP out of these things. Don't flame here, I am not saying this is appropriate for an airplane.

Run it up to 5400 RPMs, very close to 2700 prop, and close the waste gate and it really gets into the air in a hurry, like in set your hair on fire hurry. When I do this I see the MAP go from around 29" quickly up to 52". That is alot of boost but these engines are designed for it. They don't make alot of power without boost partially due to the rather low compression ratio. It also does very nicely to just run it up to about 2400 RPMs (prop, engine would be 2.02 X 2400 = 4848) and about 35" to 40" of boost. It still performs very respectfully at this setting, and the engine is basically taking it easy.

Part of the reason I was attracted to this engine was it's 300 HP,(in the car), rating but only using a portion of that in the plane. 75% of it's rated HP is 225. I will certainly not be cruising around using that much of this engine, so in theory it should last a long time and maybe be pretty reliable in doing so. Reliability of the engine is not such a big concern, gearboxes are.

If it ever wears out I will just buy another one and bolt on the externals and go at it again. I have not checked the cost, but it has to be pretty attractive compared to some of the alternatives.

Burning auto fuel is certainly a plus these days.

As I get it more cleaned up I hope to get up with some Lyc powered RVs in my area and compare speeds and fuel burns etc. I will post results when it is time

I am having fun with my STI!

Randy C