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-   -   Engine choices (https://vansairforce.net/community/showthread.php?t=122963)

tomww 02-20-2015 11:40 AM

Sensible or fun
 
If you look at the specifications the loss of cruise speed of a 160 compared to either a 180 or 200 is hardly worth worrying about.

And its hardly worth having a VP over a FP as most of the time there is no real benefit in the cruise.

You pay your money and take your choice.

Me? Well I have 200HP turning a VP prop and wouldn't have it any other way. I've done the 160HP and FP prop, and there is nothing wrong with that. But I get more smiles per hour from the extra performance and don't care about the extr costs. I fly for fun.

jacksel 02-22-2015 08:42 PM

I went with the 180hp carburated on my RV-6 and also on my RV-7. There's something utterly reliable and durable about those old Marvel-Schebler carburetors. They need all of 1 or 2 psi of fuel pressure and require a little less effort on the construction of the fuel system.

Sylvainsting 02-23-2015 12:11 AM

IO375 Aerosport
 
Hello,

I am building a RV7 in France and I choose to install a IO375 from Aerosport Power (195HP). It is the same weight than a IO360 and burn Auto fuel because it is a low compression engine (8:5). It is also balanced and the consumption is lower than a IO375. So, only advantages !. And in addition, guys from aerosport are very helpful .

Hope it helps
Sylvain

givo 12-26-2018 10:14 AM

Hi, I have the same dilemma of Daniel (dserberin) ?. I?m building an RV-7. Now I?m building the empennage kit. I am at the point where I would like to buy the QuickBuild Kit. Compiling the Van?s RV7 Quickbuild Order form, in the Finishing kit section I must select the engine: O-320-D1A, O-360-A1A, IO-360-M1B or IO-360-A1B6. I?m already flying an RV7 which I bought already built. I have decided to build one from scratch by myself and if I?ll succeed I?ll sell the actual one ;). My RV7 has an O-360-A1A that goes fine. Fuel consumption is 33 Lt/h (8,7 gal) and oil consumption is 1,2 Kg/10 hours (1,26 quarts/10 hours) it cruises at 150 - 160 kts at 75%. But I would like to go for the injection mainly for doing some aerobatic ?. so, my dilemma is between IO-360-M1B 180 hp and IO-360-A1B6 200 hp.
First, what is the reason for asking, may be is that the engine mounts are different? also the cowling?
I saw the Bill answer telling that there is only a small difference between the cruise of the 180 hp and 200 hp and that is also less expensive and lighter?. But any other suggestions?
Thanks for helping me in the choice ?.

redhawk 12-26-2018 02:19 PM

HP
 
More HP the better... even if it?s only once in your life when you really need it!
Helps re-sale as well...

tgmillso 12-26-2018 07:17 PM

Not sure I'd always agree entirely. In CO where you're already suffering from altitude performance loss before you've even left the ground I can understand, but where I am, in the summer down low, there's so much thermally driven turbulence by 10am that you're not running flat out anyway, and the takeoff performance is way better than my landing distance with a 180hp M1B. I think an issue more important than 20hp here or there is fuel availability. I filled up on BP98 (98 RON or 91MON depending on how you measure your octane) and it was $1.60 per liter. 100LL Avgas was $2.60. Getting avgas here is difficult, but high octane mogas can be purchased anywhere. The 200hp engines have a higher compression and must run 100LL (unless things have changed). I know there are people out there that run mogas in the 8.7:1, but at the end of the day they aren't approved for it. The other thing is weight. I built my aircraft as light as I could for an IFR equipped, Hartzell BA machine and still came in at 3lb over factory weight. The 200hp will smoke this as it is a significantly heavier engine. Even if you go with a lighter prop to counteract this, the CG benifit will not be as good, and may cut into your allowable baggage weight. The RV-7 is known to be a little on the tail heavy side, so you need to be thinking about this during the build (check some forum posts on the issue). Van's stresses building light for a reason. It's more payload, less stress on your airframe, more responsive and safer because of the lower stall speed. If I was to do things again i'd seriously think about an IO-320, lightweight sump, light prop on a longer engine mount to get the CG where it needs to be.
Tom.
RV-7
IO-360 M1B

Capt 12-27-2018 04:37 AM

Quote:

Originally Posted by redhawk (Post 1311906)
More HP the better... even if it?s only once in your life when you really need it!
Helps re-sale as well...

Couldn't agree more:) nothing beats cubes/HP, you can always throttle back to get the range of a smaller engine but push it up to get that high ROC and shorter take offs👍:) And yes resale is everything! -:)

jliltd 12-27-2018 07:25 AM

I suggest you take a look at the Continental Titan XIO-360. Same parallel valve envelope with 200hp for the size and weight of a parallel valve 180hp IO-360. You have options with the XIO-360 including a balanced crank, compression ratios, magnesium sump and your choice of CMI (Bendix) mags or electronic ignition or a mix. We are flying the carbureted version in a Javron and it's a smooth powerful beast. The XIO-370 would probably be my choice to replace my 180hp IO-360 if and when the time comes.


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