Sensenich VS Catto
 

I have a rv-7 with a 0-320 H2AD motor the motor has 1525 hours burns one quatr every 20 hours and the lowest cylinder is 72 lbs not bad for 3500 bucks I have put one 130 hours on this engine

I have a sessenich metal prop 80 pitch

It flew very well fairly fast once trimmed out in the 190's often but when at gross weight it lagged in climb so i wanted to make possible improvements

1 install sam james plemum yes lots of work on the h2ad motor modified vans cowl and turned out great

gained about 50 RPMs and some speed gain a few knots

for climb i orded a catto prop it is a 68long 74 pitch

I test flew with the sensenich prop then swaped the prop and flew the same with the catto

also used the heavy crush plate weight on the tail wheel stayed the same

static rpm went up to 2250/2300 rpm up from 2150

time airborn from idle to wheels off the ground using panel mounted timer gained 4 seconds

climb out at 80 mph gained 150 fpm

cruise at 5800 feet with auto pilot on no gain nor loss

I also found that during taxi it was no smoother

I did like the larger RPM range for when i was just up there dancing i didn't have to worry about overspeeding as much as the sessenich

however at certain rpm's on deaccelerate i would pick up vibration that i had never had before i could feel it in the stick it was worse on short final but only at centain rpm's

The wind had changed from the first flight and on the catto flight it was all over the place not strong but enough

I have threee more hours to put on the prop befor i can bring up people to check it a gross but so far i donn't know if the prop was worth it for me

ken flying in maine

Well, first of all... IMHO... you need a 66 x 72 for a Cruise Prop per Catto with your engine. I think you're flying the wrong prop. There is no comparison in a properly pitched Catto vs a Sensenich prop if you have the right prop for the engine.

Graig told me this is what i needed first he said that he was building me a 68 long 72 pitch but sent me 74 pitch

I have a 66 x 72 per Catto for my application and his specs for a 160 hp O320 is 66 X 72 on a 7A ... Maybe you received the wrong prop? Even on a O360 the prop is a 66 x 76.

Craig sizes his props based on engine, fueling (carb vs. FI), ignition (Duel EI, single EI, or duel mags), NW or TW, etc. There is no "standard" Catto prop.

Yep... that is true, but according to Craig three blades for RV's are all 66's... pitch does vary. I guess you could custom order a 68.

you are saying 66L for a three blade, I have a two blade it is 68L

Ken

Yep... three blade Catto props for RV's.