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3 bladed prop

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dan carley

Well Known Member
i have a rv4 with catto 3 bladed prop. had it repiched by catto i little while back, still not climbing that well. on the ground roll only getting 2100 rpms climb out at 120 mph only seeing 1400 ft per minute 100 mph maybe 1600 at 2250 rpms.

cruise is fine and top end at 2800 rpm around 209 mph.

i've asked this before just does
 
Catto Prop

Hi Dan

''cruise is fine and top end at 2800 rpm around 209 mph. ''

I think that you might be still be a little underpitch Dan at 2800RPM.But you should be seeing a better climb rate at this pitch setting.

My previous Catto 3 bladed was giving me the same reading as yours..

I've got a new Catto 3 Bladed on my -4 and the highest I.ve seen at WOT is about 2720-2750 RPM

Craig should be able to fix that.

Have you tried the same flight with a different prop ( one that you know the performance ) so that you know that it isn't the engine giving you less power than before.

Good luck and keep us posted.

Bruno
[email protected]
 
catto

bruno

thanks for the input, i wish i had another prop to try but no i don't
i did go out again and let the rv go to 130mph and then climbed a lot better. then i got 2000 fpm at first at 120 mph then she settled down to about 1800-1600 at 100mph. i'm flying off a grass strip 2200 ft. i'll have to try a payed runway

danny
 
What length and pitch 3 blade props?

Bruno and Danny,

Would you guys mind saying what length and pitch 3 blade props you have? (Danny, what yours is after the repitch?) And would you mind saying what engines you're running?

I'm wondering what 3 blade might be right for an RV-4 with an 0-320.

Thanks for any help.

PS, 209 mph top end at just 2800 sounds great to me.
 
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Catto

''Precession''

Mine is (if my memory serve me right ) a 68 x 69, 3 Bladed Carbon Fiber with the Nickel Leading Edge..

It is mounted on a RV-4 with an 0-320 (160 HP, Ported and Flow Balanced ) with Dual Electronics Ignition..

It is also as smooth as a Turbine ...

Bruno
 
Not a RV 4 or otherwise but I do have a 3 blade Catto that I ran on a Lancair 235/320 with a O-320A. Originally 150 hp rebuilt with 10:1 pistons. Prop is a 64 x 80. It would run 180 kts cruise at about 2700 rpm's.
 
dan carley said:
i have a rv4 with catto 3 bladed prop. had it repiched by catto i little while back, still not climbing that well. on the ground roll only getting 2100 rpms climb out at 120 mph only seeing 1400 ft per minute 100 mph maybe 1600 at 2250 rpms.

cruise is fine and top end at 2800 rpm around 209 mph.

i've asked this before just does
Click to expand...

If you let the airspeed build after take off until rpm reaches 2400 and climb at that rpm rather than a set IAS, it might perform better.
 
Dan, I'm not sure what engine you are flying but your numbers look prett good if you are flying with 150HP.

I have a 150HP RV-8 with a Catto pitched for cruise. My plane isn't the lightest or cleanest but is not bad.

My strait is 2050 rpm. My best climb is 1800-1500 through 5000' (starts dropping off toward 1200-800' up thru 9000') and my top speed isn't quite 170kts at 2750 rpm.

I'd assume you are lighter and may have a few more HP. If that's the case, you should beat my numbers.
 
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Danny, I'm on a 1900' grass strip too. With the -4 probably being lighter than my -8 and that little extra HP, your numbers are pretty good. If you want more climb you will lose it at cruise.
 
catto

i talked to catto today,he says let it go to about 130 mph then climb, worked better, initial fpm 2000 at 120 mph then tappers to 1800 mph at 100 mph. much better. the 3 bladed prop need more rpm then the 2 bladed

danny
 
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