Getting close input requested

[infltc2s]

Met with some of the local VAF folks last weekend and was able to snag a ride in a nice -8. Next week the wife will ride in a -6 for her sign off (fingers crossed)


The goal is to have a -7 that will cruise at 75% @ 200mph 8gph full IFR, EFIS Acft.

Engine,
If I choose a carborated 0-360, CS prop, and slider I will have all the help I need from someone close that has and is comfortable with that config.
So if I go that route can I achieve the performance desired and also operationally what's the deal with carb heat. Having only flown jets for some 20 years I'm trying to remember it seems to me that I used to use heat if the RPM was below 1500. Do you use it all the time at those RPM's or only if the temp/dew point is close? I really can't remember.
Or would it be better to just go with a injected IO-360 and find help elsewhere.
Thanks, Alan

 

[Mel]

Alan,
I prefer carbureted engines. As far as the use of carb heat, Lycoming recommends using it only when conditions are favorable for carb ice. Since the carb is mounted on the oil sump, carb ice is not as normal as say on a Continental where the carb and intake are hanging out in the breeze.

 

[JonJay]

8gph at 75% power, O360?

I will let the experts chime in as I do not have my Lyco charts, but I dont think you can get 75% power at 8gph. Certainly not with a carburated engine. Fuel injection is better balanced flow allowing for better leaning LOP, but I believe even then you are more like 70% power at 8.5gph? (assuming 180hp), I have both carburated (ellison) and fuel injected machines. I love my fuel injection in my 6.
Regardless, if you build it well, you wont be dissapointed.

 

[kentb]

Just using Vans information on the -7

200 mph
42 gal fuel
775 sm range.
That gives 10.84 gals per hour.

It the range was computed with .5 hr reserve.
That gives 10.0 gals per hour.

But I think that 8 gph is a good goal to try for and if you make a very clean plane, then just maybe...

Kent

 

[hecilopter]

I get about

200 mph consistently with a 180 hp carb, wide open, leaned and 2400 rpm at 8000 density alt at about 8.5 gph. I have the Superior XP-360, mags, carb and the Hartzell 74" blended airfoil prop. Not sure what HP I am putting out at those settings. Here is an image of the Dynon and GPS into a head wind at 2600 MSL. It's hard to tell but the head wind is about 8 MPH per the Dynon. The cell phone images are horrible, but this is wide open about 27" of MP, 2400 RPM. 198 MPH indicated and 206 mph true as read from the Dynon. Up high around 8000 DA, it goes down to about 200 to 201 mph at the same setting with the MP at about 22 - 23".

 

[infltc2s]

Very cool!!! That's what I was looking for, Thanks