Io-390
 

Hi All,
Still hot in Oz!!
Think I have decided on the Lycoming IO-390 for my RV8. Interested on any comments from all of you RV people that are smarter than me! I am pretty sure that will be everyone!
Happy new Year to All
Kevin Phillips
Ballarat
Australia :)

heavy
 

I have talked to many people and the airplane will be noes heavy

Gidday Mashy,
My dry weight comparision shows the IO-390-X at 306lbs & the IO-360-X at 300lbs. These figures sre from the BPA engine Website & seem to be the same as Lycoming.

The TMXIO-390 is basically the same engine as the IO-360-A1B6. The only difference between the two is the cylinder bore is a larger diameter on the 390 then on the 360. So they virtually look the same and weigh the same. From a layman?s weight or visual perspective, he wouldn't be able to tell the difference between the two.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at you own risk."

It's just a matter of difference pistons/cylinders right? AFAIK, you could upgrade a IO-360A1B6 to an IO-390 by doing a top overhaul.

I say go for it, battery in the back !

The hole in the crankcase where the skirt of the cylinder would go, is a bigger diameter on the 390 to accommodate the larger diameter bore of the 390 cylinder. So you can't put 390 cylinders on the IO-360-A1B6 with out modifying the crankcase, which couldn't be done unless the engine was totally disassembled.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at you own risk."

Io-390-x
 

The first IO-390-X was indeed built from an IO-360 A1B6 in the 1990's. 210+ HP for an additional 7-8 lbs? You betcha. Ross Schlotthuer put one in his RV-7. He has since sold the plane but loved the engine.

Allen

io-390 8a
 

has anyone completed a rv-8a with the io-390? any problems with the install

I flew some hours off an 8A with the 390 and I was not impressed. Builder mentioned there were no material install issues.
Im still a firm believer that the parallel valve 180 is the way to go on the 8 using a four banger. I have 2 guys I fly with with the 200hp angle valve and they both wish they went with the parallel valve. The 20 hp is not worth the extra weight.
My 2 cents.
best,

I have an RV-8 with a 200HP angle valve and a whirlwind prop. I like it a lot.

The firewall forward weight is about the same as a parallel valve/Hartzell combination. I was careful with other stuff, and my C of G is at 78.5" which is further aft than most -8s, even though my Odyssey battery is on the firewall.

I have flown a 180hp/hartzell -8A a good bit, and I like my plane better. It is smoother and noticeably more powerful.

There is an -8A going together in my hangar right now with an IO-390. No issues at all with the install AFAIK. They have been using my IO-360 as a "Chinese blueprint" for the FWF.