IO-390

Can anyone explain why it would be worth spending $40,000 for a IO-390?
How much is really gained over using a 180 hp IO-360? I'm really just concerned with cruise speeds.

[schristo@mac.com]

I bought mine at the same cost as a similar 200 hp angle valve several years ago; now an injected 180 hp costs nearly as much as I payed! Prices of all engines have been trending up steeply lately but the 390 is getting way too expensive... If I was buying today I would focus an IO375.

[Bob Axsom]

If you are interested in looking at camparable speeds in RVs of various types go to www.sportairrace.org, click on Records and Stats, then League Statistics, then All Speeds by Aircraft Type and an Excel file will be downloaded to your computer that you can scroll through at your leisure than delete. Most of the RVs in the RV Gold class have 390s and the RV Blues have 360s (some IO some O or generally 200hp angle valve or 180hp parallel valve). The exceptions are John Huft and Dave Anders who have 360s but they kick backside in the RV Blue class so bad they moved up and kicked some 390s. If you're not racing and are on a budget as most of us are the 390 is hard to justify.

Bob Axsom

P.S. RV Red is for RVs with 320s or smaller engines.

[MCA]

When I bought my -390 in '05 it was several thousand less than a 200HP angle valve -360. At the time the -390 was exp only but now it is certified. Perhaps that made a difference.

[hydroguy2]

It all depends on how much fuel you want to burn. At cruise, burning 8.5gph most all the -7's will be 175kts TAS (give or take) no matter what engine is under the hood. If you start pouring the coal to it the IO-390 will pull away.

So pick your mission and pay at the vendor and again at the pump. Horsepower costs money, how fast do you want go.

BTW I wanted a 390 and then I started saving for a IO-375.....then looking at my wallet, reality set in. I ended up with a 180hp parallel valve O-360 but modified with 9-1pistons, Pmags and Superior cold sump & AFP injection. Cost ready to run <$21000. It does ok in the horsepower dept. I see 189ktsTAS, but prefer not to look at fuel flow while doing it.

[Bob Axsom]

Originally Posted by hydroguy2

I see 189ktsTAS, but prefer not to look at fuel flow while doing it.

I can't break 185 no matter what I do in level flight. Some day I am going to have to address the power end of speed, Sigh ...

Bob Axsom

The xp-io-360 from superior can still be had from superior for $15k less, can it not?

[islandmonkey]

Originally Posted by Bob Axsom

I can't break 185 no matter what I do in level flight. Some day I am going to have to address the power end of speed, Sigh ...

Bob Axsom

Bob, I bet you have plans already in place on the power end of your 6a. If not, start on the plans now and look at the timeline for completion. This will give you a good wintertime project that will keep you busy after the racing season has finished. If your up for it and I can make it over to the States I would be very happy to give you a helping hand on one of the stages.

[hydroguy2]

Originally Posted by paul mosher

The xp-io-360 from superior can still be had from superior for $15k less, can it not?

not new and ready to fly

I think you can find a kit for somewhere around that number, but you still have stuff to put on it to be ready to fly. When I was shopping a few years ago, kits ere about $14K but ready to fly was closer to $19....then add a few extra goodies and I wasn't able to get it under $21. Then by the time I saved a little more money the price of engines kept creeping up faster than I as collecting $.

[Bob Axsom]

Originally Posted by islandmonkey

Bob, I bet you have plans already in place on the power end of your 6a. If not, start on the plans now and look at the timeline for completion. This will give you a good wintertime project that will keep you busy after the racing season has finished. If your up for it and I can make it over to the States I would be very happy to give you a helping hand on one of the stages.

I'm planning an all out effort to win it all this year then I may focus on travel. I feel like this is a transition time near the end of my life so I am not hard over one way or another. If I continue with racing intensity I may get a 390 and give the golden boys a run. I also have considered going for some world records through the NAA (and FAI), try to fly around the world or just become a meandering bum with an airplane.

But you get well and come for a visit anyway.

Bob Axsom