About to place my order for RV-7 - a few questions

[paulincapetown]

Am about to place my order for an RV7 kit from Vans (today/ tomorrow) and have determined that I can?t afford a v/p prop. I have however decided to continue with the purchase of my Lyc IO -360. Hopefully in a couple of years time I will be able to afford the propeller. In the meantime, my builder will plumb it all in so that when I am ready, will literally have to just attach the prop and gov etc but cabling will already be in place.

My questions are:
1. Is this a sensible approach? - should I continue with the purchase of an IO -360 engine and accessories (except the prop) or
2. should I just accept that the performance of a normally aspirated engine( XO 360) will be fine and sufficient for my purpose -which will be some aeros but mainly cross country and off field landings.
3. And finally is the roughly $10,000 difference between a F/P and V/P worth it?

I know this is an age old question but keep getting different advice. Would really appreciate comments from this forum

Paul

[robertahegy]

I was very happy with the performance of my 7A with an 0-360 A1A and Hartzell BA prop. The systems are less complicated and the difference in performance isn't worth the extra expense. JMHO

Roberta

[RV7ator]

A constant speed prop will yield obvious, exciting performance for your money. You really can't tell anything special between fuel injection and a carburetor except FI costs a lot more to get in the air.

Also, the price difference between prop types is a lot less than $10,000. My gut this morning says $6,000.

John Siebold
Boise, ID

Want to buy a flying RV-7? One of mine is for sale. See Barnstormers.com

[flybill7]

If you are just ordering the kit, you have a couple of years before you need, or should, order the engine & prop. Plenty of time to think about the decision. I have a carb O-360 (Mattituck TMX-360) and Hartzell BA CS prop on my RV-7. The CS prop is nice, especially for slowing down. For me the money was worth it.

[uk_figs]

I decided to go FP for simplicity, reduced cost and it was what I was comfortable with, I did however build the engine with the hollow crank to be able to convert to CS in the future if I changed my mind. I first flew with the Sensenich metal prop and now have a 3 blade Catto which I love. Some comments for you to consider based on my experience with my setup:
1. With the FP metal prop the 7 does not slow down quickly in the pattern so you have to think about speed management more so than the guys I fly with do with the CS. The Catto is better in this regard than the metal prop I think because of less inertia so the motor winds down quicker.
2. The CS guys I fly with take off quicker and climb a little better but my 7 is no slouch in this area either
3. The 7 was I believe designed up for CS and the resultant added prop weight up front. From a CG perspective with my FP setup to be able to carry 100 lbs in the baggage area with min fuel I needed more weight up front so I added a Landoll harmonic balancer to the fly wheel to put more weight up front. This did the trick with the Sensi but I had to add an additional sabre weighted spacer with the catto due to the significant weight difference between the two props to bring things back into the desired cg range.
4. I do not fly formation but have read here that CS is very helpfull in this regard
5. I do gentleman's acro occasionally and you have to watch for engine over-speed on the down line with the FP

There are probably more things to consider but this has been beat to death on these forums and my buddy Larry Adamson will probably jump all over this post

From my perspective I am happy with my choice and do not plan to change but that is just one persons opinion.
Dave

[N282S]

I took transition training in a fixed pitch 7. I was amazed at the performance AND smoothness of the 3 blade Catto. When I built mine, there was little discussion in my mind as to CS or Fixed. I just ordered the CS. I do a couple of long XC each year from Topeka to LA, once to Osh, and maybe one or two more shorter ones. Sure the CS gives you a bit better mileage, however I doubt I will ever get my money back. And, I suppose at the time where I do recover the money it will be time for a prop overhaul. Where the CS really shines for me is in acro. But, at my age and stomach, I don't do that much acro. Prop type is strictly a personal choice. As to the pre-purchase of governor and cable, I guess it depends if your willing to forego the 1200 bucks now or later. I would wait, but I'm not you. So, what did you learn here? Nothing. Sorry.

[Jerry Cochran]

You really can't tell anything special between fuel injection and a carburetor except FI costs a lot more to get in the air.

Except... Never a worry about carb ice, the ability to run LOP (lean of peak) which in the course of the next 2000hrs saves moolah, the ability to get your investment back at the time of sale...

Constant speed or not?

the ability to use ALL your horses on TO and climb, the ability to optimize performance at ANY altitude, smoother running...

That's all...

I have owned 2 -6a's, one bought with a carbed O-360 and mine that I built with an IO-360 and a Harzell BA. NEVER will I go back.

YMMV

[paulincapetown]

I have decided to go the CS route after all and will have to do the penance for this extra cost over the next 25 years
Thanks for the advice guys - really appreciated