L

Levrie

Active Member
I have to make choices for my Finish Kit/Power Plant very soon and, and before the FEB. price hike and would like to hear from builders/flyers as to the following:

Aircraft is RV-8A. and just finishing QB fuse fit out. I'm not a performance geek and want to try and keep the a/c goals to the original Van's concept, Simple, Functional and Economic!

Current choice of manufacturer is Superior, current model choice is (new) IO360. (Superior have plant nearby)

Q) Should this be Vertical/Horizontal induction? Strengths/Weaknesses? Build facilitation? Is there a choice?

I will fit a FP prop but have a hollow crankshaft (plugged) for future VP development subject to funds.

Q) Has any one else got this sort of intention? Is it viable? Which FP prop?

Aircraft will mostly fly from good tarmac fields and be used for short cross country flights of approx 200nm legs and in mostly summer.

Your opinion/views are welcome and I would particularly value comments from people who might have done things different if they could 'do it all again' differently!

David
 
Horizontal

Either way the plane will perform great.

I would go for Horizontal if I had a 7 or 8. The incremental cost and build time is small, and you have a more efficient engine.

I am building a RV-6 and already own the stock Van's RV-6 cowl so it will be much more difficult to do so for me. If I can figure a practical way to do it I will consider Horizontal, but short of buying a new cowl I'm not there yet.

Regards,
 
Propellor and engine combo

I talked to a few people who fly behind Sensenich fix pitch props sold at Vans. They perform really well. However if engine and airframe smoothness is a quality you would like, try a wooden prop. They are absolutely amazing in that department, however do not fly in rain, and regularily check prop bolt torques as they can change due to changes in humidiity.

There are are many options. Just figure out which ones are the most important to you.

As far as engines go, one thing I would try to incorporate is a way to burn lower octane fuels. No one knows how long we will have 100ll for so having an engine that will run on say 80 octane fuel (mogas)might keep you airborne. An 0-360 could have low compression pistons installed, still develope close to 170hp, and run on regular unleaded. just a thought.

jarvis
 
I hear that plugs will foul fairly quickly if you have low comp pistons and then run 100LL (due to occasional unavailability of no-lead) Can anybody speak to that with authority?
 
Horizontal induction is more expensive

I am also building an 8A and I chose the horizontal induction, mostly for looks. There is no real performance difference as far as I can tell, but it certainly looks nice. Having said that, the horizontal induction is more expensive. Superior will charge you another $1K for a horizontal induction sump. On top of that, Vans will charge you for the "snorkel" induction to go inside of the cowl. I was all set to order the vertical induction and two of my "friends" kept telling me that the horizontal cowl, without the bump, looked so much cooler. Now, if I could only get each of them to kick in $600, then I would come out cheaper. Oh well, I did not get into airplane building to save money.
 
The cowl is the determinant for me

David,

Here's another perspective: I wanted a Sam James Cowl / Plenum since reducing drag is a high priority of mine. It seems to have the track record and science behind it to prove its worth and it offers what I think is perhaps the best cost/benefit of any speed/efficiency mod I've seen.

I don't want a prop extension as I'm going constant speed aluminum and will fly some aerobatics and I'd just as soon not risk the extension. This means the James "stubby" cowl, which means vertical induction is the only option.

I'm fine with the look and the performance should be close. The air has to turn 90 degrees no matter how you slice it, and while I'd love to have the cold air sump I'm saving $1,000+ by sticking with the vertical.

Since you're building a nose-dragger, I believe you need to look at the entire combo: cowl / engine / sump / induction / exhaust to make sure you're prepared for whatever adventure awaits you in fitting it all together.

George
 
I'm running the Superior IO-360, forward induction, using a FP Catto-3 blade prop and am very happy with the performance & smooth running combination.

I also have the hollow crank in the event I choose to go CS someday.

I don't remember Vans charging extra for the snorkel-less cowl.
BTW, I use 93 unleaded almost exclusively except while enroute.
 
100LL and Low Compression

Rupester said:
I hear that plugs will foul fairly quickly if you have low comp pistons and then run 100LL (due to occasional unavailability of no-lead) Can anybody speak to that with authority?
Click to expand...

I regularly fly an O320E2D with 7/1 pistons on 100LL. If you lean during taxi and push the mix knob in when your ready to roll, you will have no problems with LC pistons on 100LL.

I have been doing this for 10 years and about 1000 hours, no problem.

Have several friends doing the same in 150HP RV-4's. Again, no problem when ground leaning.

Regards,
 
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