L2 speed question

[Ed O'Brien]

L2 owners;
I'm putting a C-85 and I'm thinking of replacing the my Sensenich (wood) with a McCauley. Right now the pitch is 48 -- it's a cruise prop. Being in Denver, I want to get over the mountains occasionally -- I want as much speed as I can get -- I want as long a legs as I can get (remember there's only 14 gallons on board). Given this criteria:
1. What's the optimum blade pitch? (Mileage efficency)
2. What's the expected speed increase over A-65 w/wooden prop (44pitch)?
3. What's my flight plan fuel burn per hour?
4. Since I can repitch the McCauley to anything I want -- what would you do? This isn't a test but I do have questions.
With regards; Ed OBRIEN

[Ragwing nut]

Re: L2 speed question

L2 owners;
I'm putting a C-85 and I'm thinking of replacing the my Sensenich (wood) with a McCauley. Right now the pitch is 48 -- it's a cruise prop. Being in Denver, I want to get over the mountains occasionally -- I want as much speed as I can get -- I want as long a legs as I can get (remember there's only 14 gallons on board). Given this criteria:
1. What's the optimum blade pitch? (Mileage efficency)
2. What's the expected speed increase over A-65 w/wooden prop (44pitch)?
3. What's my flight plan fuel burn per hour?
4. Since I can repitch the McCauley to anything I want -- what would you do? This isn't a test but I do have questions.
With regards; Ed OBRIEN

The L-2M we did with an 85-12 had a McCauley 71-48 and would run 105 indicated. For Denver I would back it down to a 44 for climb performance in the summer.

Mike

[crispy critter]

Re: L2 speed question

Ed,
I might have a 71/48 for sale. Let me know if your interested.

[Dick Huish]

Re: L2 speed question

I agree with Mike. The 71-48 seems to the ideal prop for a C-85 on the L-2.ick

[Ed O'Brien]

Re: L2 speed question

Thanks guys!!! Any ideas as to fuel burn per hour on a 85-12 (but no electrics) with a 71-48? I think I'd prefer a 71-46 to get up high. I need atleast 12,500 to get over the Rockies on a standard day and 15-16K pressure altitude in summer. I'm hoping for 105mph and still 2.5 hours gas. Everywhere I want to fly is about 450-500 miles away. One gas stop v 2 stops makes a big difference in a trip.

Kevin I might be interest in your blade. Give me a call. My McCauley is 1000th under for the shop to overhaul. New is $2500. So I'm looking. Thanks; ED OBRIEN

[astjp2]

Re: L2 speed question

Well I was at Ogden with 4500 msl field elevation and I was using a Sensiech m74ck repitched to 43, you need the climb for the density altitude's of 7-9k during the summer. The longer the prop, the more efficient it will climb. I can cruise by myself with full fuel and have a speed of 100 kias@2650 rpm. Rock Springs WY, has a 7000' runway and I have seen 13k density altitudes, if you have a cruise prop, plan on using 6000' of pavement. Oh well just a few thoughts. Tim

[Ragwing nut]

Re: L2 speed question

As I said above, the 48 pitch works ok for us low altitude folk but for Denver you need probably a 44 pitch for those hot summer days. We figured 6 gal/hr burn

Mike

[srf471]

Re: L2 speed question

OK Guys,

I have a L2M in Florida, C85-12 with a McCauley 71-46 prop.

The best I get is about 92 indicated at 2450RPM

What are you guys doing to get 100+

Nick
TF#695

[Ed O'Brien]

Re: L2 speed question

Around Denver: where most airports start at 5000 ft and 6500ft will smack you into radio towers... so 7500 ft is a pretty standard altitude for everyday flying around. I can't speak to the L2 because as I'm still getting used to it -- but a BC-12D cruises fastest 6500-7500 ft or so. So the answer between slow and low and faster... is likely higher.
With regards; ED OBRIEN

[Ragwing nut]

Re: L2 speed question

OK Guys,

I have a L2M in Florida, C85-12 with a McCauley 71-46 prop.

The best I get is about 92 indicated at 2450RPM

What are you guys doing to get 100+

Nick
TF#695

Check your rigging, and check your pitot tube angle in level flight and make sure it is 90* to level flight attitude.

Mike