IO-360 vs. IO 375

[The Wizzard]

I understand the proprietary nature of the IO-375 and Aerosport Engines. I am trying to decide which way to go. Does anybody have any insights into this dilemma? RV-8, constant speed prop. Pros., cons?

[pjaffray]

My plan is to go with the IO-375 for my RV-8. I haven't ordered it yet but my understanding is the only non IO-360 part is the crank. I have read the posts of lots of happy customers running the 375 on this site. The mogas version still gets you more power than the stock 360 with the option of the less expensive fuel. Seems to me to be a win-win.

pdj

[David Z]

Is the mogas version ethanol compliant?

Originally Posted by pjaffray

The mogas version still gets you more power than the stock 360 with the option of the less expensive fuel.
pdj

[LarryT]

Search the archives for Frankh posts. He has been running mogas with ethanol for years/400+ hours. Among other things he is a talented mechanical engineer who designed a hydraulically correct fuel delivery system.

Larry Tompkins
N544WB -6A purchased flying
W52 Battle Ground, WA

[GusBiz]

Originally Posted by David Z

Is the mogas version ethanol compliant?

If you contact Bart and Sue of Aerosportpower you will get this response
"....the only rubber in the IO-375 fuel system components supplied with the engine are the fuel diaphragm, o-rings in the fuel servo and the diaphragm in the engine driven fuel pump. All fuel hoses supplied are Teflon lined. Compatibility with fuels containing ethanol would need to be tested by the user....they don?t know if these parts would be effected and there is no replacement other than the standard production parts"

This means they cannot provide tested ethol resistant componants. It doesn't mean there are none in the world but certainly they will not be coming from Aerosport.

[frankh]

as far as running an IO375 on 10% ethanol.

I guess I'm not seing the difference between the IO360 and 375 as far as fuel is concerned. they will both run on mogas but some design work will be needed for running it on street gas.

If you can live without the mechanical pump then its not hard to get there from here.

Just the fact I am not pumping lead into the atmosphere gives me peace of mind and not fouling the engine with lead either and a lot less cost are benefits not to be sniffed at.

Frank

[Jeff kudlo]

I have chosen the Aero Sport IO-375 and a constant speed Whirl Wind RV200 prop. I selected the standard version compression, which will allow some flexibility to use mogas if forced to. My decision was made partially by the testimonies on VAF then finalized by a personal visit to the suppliers.

Both very reputable.

The link below is my IO-375 in assembly and test cell:

http://vimeo.com/22786085

[RV7ator]

I've ordered and flown 360s and a 375 from ASP, but carbed. Bigger engine equals more power, it was performance measurable, but not drastic. A bit more gas.

Bart told me if ASP tanks or he croaks, the proprietary crank goes viral, anyone can buy it, so no maintenance worries.

ASP will make any compression you want. I asked for 9:1 to use mogas.

John Siebold

[frankh]

Originally Posted by LarryT

Search the archives for Frankh posts. He has been running mogas with ethanol for years/400+ hours. Among other things he is a talented mechanical engineer who designed a hydraulically correct fuel delivery system.

Larry Tompkins
N544WB -6A purchased flying
W52 Battle Ground, WA

Considering that Larry is also a registered professional engineer in the State of Oregon thats quite some kudos..

Actually the FI's IO360 RV has run about 400 hours on 10% ethanol laden mogas. the carburated zodiac before it had about 700 hours. Both airplanes used variations on the electric only fuel pump system.

I run mostly LOP on the FI's motor.

If the two engines were the same price I'd probably go for the IO375 for the extra displacement.

Frank

[C-GRVT]

consider whether the prop that you propose to use is compatible with the engine. What props are approved/vibration tested with an IO 375?
Bill Brooks
Ottawa, Canada
RV-6A finishing