Performance on Floats

[MNJoe]

Re: Performance on Floats

Mine is a modified BC-12D The intereseting part is my 18 year old son's landing on the water are better then mine!! Guess I taught him well.

Joe

[Chris in Idaho]

Re: Performance on Floats

Yes, sounds like you've taught him well. What prop are you running?

[NY86]

Re: Performance on Floats

Th Is a 76AK-2-40 actually 76 inches long?

This designation means they started with the 76AK forging, which is 76" long, cut 2" off to make a 74" prop, and pitched it to 40".

[d.a.]

Re: Performance on Floats

Is it possible to get full length 76 inch props, legalities aside?

[d.a.]

Re: Performance on Floats

An interesting side note to this thread has been individual’s assessments of the performance of the various floats that are available. I’ve always thought the EDO 1320s were the float of choice for T-Crafts and Cubs. Now I’m hearing they might be a little under floated for a T-Craft. The 1400s have more buoyancy but some don’t like the flat bottoms. The Aquas are heavy possibly, I think I saw somewhere that PeeKay makes a T-Craft float and everyone seems to like the Bauman 1500.

I would be curious to read everyone’s opinion on the available floats. In order of preference, which ones do you like, which ones do you not like as much and why. I’d also be curious how many floats are useable on a T-Craft. I think I also saw a reference to Bauman 1420s?

[NY86]

Re: Performance on Floats

Is it possible to get full length 76 inch props, legalities aside?

Yeah, but not to fit (mechanically) these engines...

McCauley makes 1B90CM props up to 78", but they won't approve them in that length for any known engine. the longest is a 76 on an A65.

[d.a.]

Re: Performance on Floats

NY86,
Thanks for the info. It would be great if they would sell an extra long prop for Continentals for added take off performance. Same principal as a Borer Prop.
D.A.

[flykenken]

Re: Performance on Floats

With a 71/41 prop and 1320 floats you are underpropped and when heavy you are underfloated as well. Everything has its plus and minuses. By being underpropped you aren't normally overworking the engine and you have some extra rpm when you need it. And with a shorter prop you pick up less water when heavy or in rough conditions. The shorter prop also lets you turn in a smaller radius in the air. With 1500s you now carry over 30 extra lbs which once you are airborne hurt your climb and cruise (not to mention over 5 percent of your useful load) so now you may have to do that extra circle to get over the ridge - or just follow the river valley which means more gas and even more weight and less useful load. For me I want less weight. The pluses of the 1500 floats is they will handle rough water better and alot of 1320s are old and tired and may need alot of work to keep floating so if you don't already have floats then 1500s might be the way to go. I'd also recommend a skylite on floats as you will be way more comfortable doing medium bank turns in slow flight at low level and steep turns when cruising.

[d.a.]

Re: Performance on Floats

FLYKENKEN,
Thanks for the input. Sounds like personal mission objectives still dictate which float is best.

When you performed your C85-O200 Crank Mod, would you say there was there a dramatic night and day difference in performance, or was it only slightly noticeable?

Thanks.

[flykenken]

Re: Performance on Floats

I picked up 200 static rpm and it made a huge difference in performance. Also threw out the stromberg carb - after first beating it with a hammer - and put a precision carb on. The precision carb is way better in winter.

[Larry Lyons]

Re: Performance on Floats

FLYKENKEN,
Thanks for the input. Sounds like personal mission objectives still dictate which float is best.

When you performed your C85-O200 Crank Mod, would you say there was there a dramatic night and day difference in performance, or was it only slightly noticeable?

Thanks.

I missed the Forum at Airventure where they were going to talk about all this stuff, but did hear 2 testimonials that stated that this combo gives markedly better performance. They Estimated the HP to be 95 or better.
Larry

[flykenken]

Re: Performance on Floats

Just did a 2 person t/o 2100 asl alt 29.88 temp 60, 1370 lbs, 7-8 kt wind in 25 seconds. So you see how important a bit of wind is

[flykenken]

Re: Performance on Floats

Oh, I should add that the T/O above was against a 4 kt current too. When you add current to the wind it makes the water a bit rougher. After T/O we climbed to and maintained 4500asl cyl head temps normal oil temp 190 OAT 50 at altitude. Because of the slower cruise on floats your oil temps are often 20-40 degrees higher than on wheels.

[d.a.]

Re: Performance on Floats

Great info, thanks.

[Dano"T"]

Re: Performance on Floats

The C90 was approved by buying the Harer STC, performing all mods except substitute a C-90 for C-85 and file a 337. You are allowwed up to 10% HP increase at the field approval level...Just got back from Oshkosh....had a great time. Oh....the 76AK-2-40 prop actually measures just over 74.25" on the tape.