IO-390 in RV8

Lucky Aviation · #1 08-17-2020, 04:18 PM

I am considering installing a IO-390 in my RV8, I understand that there are challenges, are there any builders out there that have done this? Have you any advice?

N546RV · #2 08-17-2020, 05:13 PM

Paging Dan Horton to the engineering lounge...

Northernliving · #3 08-17-2020, 05:35 PM

Quote:

Originally Posted by Lucky Aviation

I am considering installing a IO-390 in my RV8, I understand that there are challenges, are there any builders out there that have done this? Have you any advice?

Mark Spickard put one nine years ago. I'm sure there are others.
https://www.youtube.com/watch?v=r2IeuNGtn94
https://www.youtube.com/watch?v=tqSpCoZvlqs

Lucky Aviation · #4 08-17-2020, 05:46 PM

Thanks Brian, this helps!

scsmith · #5 08-17-2020, 07:25 PM

I don't think it is a secret anymore that Van's is about to announce that they will expand the range of recommended engines to include the IO-390-EXP 119.

Along with that announcement, I would suspect over time the emergence of factory-offered accessories to make the installation more straightforward than it was for the pathfinders like DanH and others.

This is exciting enough to make me a repeat offender in the coming year or two.

walter · #6 08-18-2020, 10:50 AM

I have an Barrett IO-390-X in my 8A. I used the RV-14 baffle kit and it went on like a glove. I have a Whirlwind 74HRT prop, dual P-Mags dual Garmin G3X touch, GTN 650 with Autopilot, aft mounted Garmin Transponder, aft mounted Garmin radio and ELT. Firewall mounted EarthX battery and Showplanes Fastback. Empty weight is 1119 #. and useful load 681 #. Full fuel and single pilot (190 #) I need 5 # in the aft baggage compartment to stay within CG on takeoff. if I use all my fuel I need 10 #. to stay within CG for landing. Nose Gear Weight: 326, Left main: 394, Right main: 399. Hope that helps. First flight is soon.

Freemasm · #7 08-18-2020, 11:25 AM

Got that out of the way. One annoying thing about forums people, want to argue that they are correct or want their choices validated. I'm not doing that. Also, I'm building something other than an 8.

Why wouldn't you consider a stroked straight valve or a higher compression straight valve engine from one of the custom shops? It just seems so much easier installation for a very small, if any WOT performance hit. Would be a little bit lighter, BTW.

Few will argue that the Lycoming straight valve engines are as close to bullet proof as they get. Yes, I'm aware that some design margin is utilized with said mods but there's enough run history that eases that concern. The aforementioned options would save so much build time and anguish in an 8.

Once again, I'm not saying I'm right but I'm going with a stroked, injected, improved sump, EI, EFI, straight valve engine that will make almost the exact same HP @2700. The better torque curve (an under valued characteristic) should really be evident in cruise settings. The build would seem so much simpler.

I like hearing other's reasoning. I'm curious. Please fire away.

DanH · #8 08-18-2020, 11:35 AM

Quote:

Originally Posted by Freemasm

The aforementioned options would save so much build time and anguish in an 8.

What anguish? A stock 390 installs just like a stock angle valve 360.

I gave myself lots of extra work for custom stuff, but I'm crazy.

Taltruda · #9 08-18-2020, 11:58 AM

Quote:

Originally Posted by Freemasm

Got that out of the way. One annoying thing about forums people, want to argue that they are correct or want their choices validated. I'm not doing that. Also, I'm building something other than an 8.

Why wouldn't you consider a stroked straight valve or a higher compression straight valve engine from one of the custom shops? It just seems so much easier installation for a very small, if any WOT performance hit. Would be a little bit lighter, BTW.

Few will argue that the Lycoming straight valve engines are as close to bullet proof as they get. Yes, I'm aware that some design margin is utilized with said mods but there's enough run history that eases that concern. The aforementioned options would save so much build time and anguish in an 8.

Once again, I'm not saying I'm right but I'm going with a stroked, injected, improved sump, EI, EFI, straight valve engine that will make almost the exact same HP @2700. The better torque curve (an under valued characteristic) should really be evident in cruise settings. The build would seem so much simpler.

I like hearing other's reasoning. I'm curious. Please fire away.

I'm with you. .I am looking to keep the parallel valve engine, and tweak it. I would rather give up a few hp for the lighter weight. .and with the hotrod shops out there, I don't think you really have to give up anything! I understand the guys going turbo, supercharger or nitrous wanting to use the angle valve engine. . I believe they are easier to keep the cylinders cool.

Freemasm · #10 08-18-2020, 12:03 PM

Quote:

Originally Posted by DanH

What anguish? A stock 390 installs just like a stock angle valve 360.

I gave myself lots of extra work for custom stuff, but I'm crazy.

My personal anguish is that I'm an ill-informed idiot. Was told the RV-8 only had factory options for the O-360. Went and looked at the Vans site so that's at least outdated if not always wrong.

Sorry. Opinions on PP selection process would still be welcome and appreciated.