Well, I'm back from OSH and altho it will be a few more months before I need to decide for sure I'm looking for some input on engine choices for the -8.
I like the idea of a larger displacement / low compression engine that is "loafing" more than a high output tuned engine. I talked with Allen Barrett at length about the IO-390; he is putting one in his -8. My main concern is W&B. I have read all the info about building light, forward CG, etc and really don't want a heavy / nose heavy plane. There doesn't seem to be any info on Checkoway's W&B site for the 390; additionally, there are parallel valve engine setups that are heavier and nose heavier than some of the angle valve setups on the list.
I think if I go with the IO-390 I will almost be obligated to get a composite prop.
If money were not a concern (I wish!) what would you guys pick as the "ultimate" combo for the -8? I'm thinking maybe the IO-390 and the Aerocomposites prop. The 340 stroker is an interesting engine, but leaves little alternative if 100LL becomes a problem in the future. Allen Barrett said the 390 could burn ethanol (anyone see the ethanol powered fleet of RV-3's and -8 from SD at OSH - pretty cool!!)
More engine questions
- captain_john
- Sparky
- Posts: 5880
- Joined: Sun Oct 31, 2004 9:17 am
- Location: KPYM
Thomas, to be perfectly honest with you, if I were building an -8 I would install a nicely tuned IO-360with para valves.
The -8 is better balanced that way and would be very efficient and cost effective.
OTOH, Dick Martin has a SCREAMER of an -8 and it is just like you described. It has the 390, Aerocomposites airscrew and goes like the hammers of Hell, so I hear. If that is what you are after, then your decision is made.
There is a website called www.io-390.com where a -7 driver has detailed his installation.
Also, on Dan's W&B page it seems that the -8's with 360's and 185 hp do quite well all around!
Me? I am building a tail heavy and wide -7 that would benefit from the heavier engine. That is why I am planning on the 390. But that is a different story alltogether.
Does that help you deceide?
CJ
The -8 is better balanced that way and would be very efficient and cost effective.
OTOH, Dick Martin has a SCREAMER of an -8 and it is just like you described. It has the 390, Aerocomposites airscrew and goes like the hammers of Hell, so I hear. If that is what you are after, then your decision is made.
There is a website called www.io-390.com where a -7 driver has detailed his installation.
Also, on Dan's W&B page it seems that the -8's with 360's and 185 hp do quite well all around!
Me? I am building a tail heavy and wide -7 that would benefit from the heavier engine. That is why I am planning on the 390. But that is a different story alltogether.
Does that help you deceide?
CJ
RV-7
Garmin G3X with VP-X & a TMX-IO-360 with G3i
It's all over but the flying! 800+ hours in only 3 years!
Garmin G3X with VP-X & a TMX-IO-360 with G3i
It's all over but the flying! 800+ hours in only 3 years!
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- Class E
- Posts: 103
- Joined: Sat Nov 13, 2004 9:35 pm
- Location: Palmer, Alaska
Not much help but...
I know this isn't much help but I will say I was very impressed with Barrett. I spoke to Monty and Rhonda at lenghth and they answered all of the questions I came up with and never made me feel liek I was imposing on them. I can't say that about all of the engine builders I spoke to.
The 390 they had on display was absolutely beautiful! With that said I was a little disappointed with the price difference between it and the 360s. I'm sure we will end up with a 360 in our 7A. That 390 sure looks good though!
The 390 they had on display was absolutely beautiful! With that said I was a little disappointed with the price difference between it and the 360s. I'm sure we will end up with a 360 in our 7A. That 390 sure looks good though!
JohnR
RV-7A - Fuselage - SOLD, just not supposed to be
Numbers 6:24 - The LORD bless thee, and keep thee
RV-7A - Fuselage - SOLD, just not supposed to be
Numbers 6:24 - The LORD bless thee, and keep thee