Propping a 27 Fountain
 

Hello everyone, I'm a newbie and have a question, I have a 05 27 Fever with stock 496HO and bravo 28 four blade, i'm turning it 5200 at 68mph. This motors operating range is 4600-5000 rpms, full fuel with 2 people onboard. I'm looking to get it back in operating rpms, any advice appreciated in advance, thankyou!!

I was curious about my 29. So I called Fountain and right away they faxed me a copy of the original test run sheet. Props, RPMs, Speed, etc. etc. Thier phone number is on thier web site.

I have the test data sheet from the factory, same #'s as far as rpm's, but they recorded 71 mph with half load of fuel and one person in the boat. I'm thinking a 29-30 pitch should bring my R's down to something like 48-4900.....

However, young grasshopper - the Pamlico River is sacred, special water. YMMV.

...sorry, had to say it.

I have a custom B Blades prop that will do exactly that. It was custom made for my 05 27 fountain with 496HO. On my boat it does 4960 rpm at 65 mph. You can have it for 300 plus shipping. It's perfect. [email protected]

Yeah, I'm sure it is............

I appreciate it Jim, but I don't wanna lose that much on topend, but I'll keep you in mind. Thanks

Our old 27 had a 502 / 415hp with Bravo One drive. A little different than yours, but a labbed Bravo I 24p (RH) made it run right at 69.5 mph GPS.

I have same boat as you but 2002.. out of the factory was with a Bravo 1 24P 4 blades doing 65 mph half tank... now running Bravo 1 26P 4 blades.. 68-70mph with full tank and 3-4 persons onbord @ 4950 rpm.. i'm very surprised to see 5200 rpm with your 28P.. it must take forever to jump out of the hole.

I talked to Brad today at BBlades, he wants me to check tach as I'm not hearing any beeps from rev limiter, so i'll do just that. I would think the Livorski gauges would be spot on, but...... Also my drive is a X model with 1.65 ratio, I'm not sure what earlier models had as far as ratio, maybe 1.5's?? Thanks everyone for the replies, big and slow Fountain is different than my old Hydrostream V-king with a 2.4 Bridgeport, but it's still fun to drive. :)

You are talking apples and oranges. Pre 496 boats typically had 1.50:1 drives. The 496 boats had/have 1.65:1 drives, hence the higher pitch props.

As you can see above BBlades prop was not an improvement on my boat. I sent it back and it still slowed the boat down.

I'm thinking a 30 Bravo one, if I find that the Tach is reading correctly. Thanks for everyones replys, I appreciate it!!

I also have a 496HO.. but 1:50 ratio.. here's why 26 pitch for me.

I have played with this combo forever and a brand new perfect shape 28 bravo cannot be beat. I did have a 30 bravo that ran well but had to be labbed to get the RPMs up

I have an 04 27 with the same set up. I run a 30 bravo and turn 5000 rpm with 2 on board light fuel at 69mph. Tried a 28 and was all over the limiter. Next step I am gonna try a p5x hydro but I think 70 will be the max for this combo. 30 bravo cruises way better than the 28 IMO.

Matt

If Fountain could have just done a prop change and picked up 2 mph they would have done it.

You're right there. If you install a simple SmartCraft Gauge or put a computer on it you will see that your tach is slightly off. 5150 is the stock limiter in the 555. You have a 1.65 drive. With a light load of fuel and by yourself, you will bump the limiter a little if trimmed at about 5 or just barely, barely over 5 (say 5.1 or 5.2).

Jason did a bunch of prop and drive testing with that boat (SDFever).

The tooth count difference on the gears from 1.5 to 1.65 is 2. Consequently, two teeth are equal to two inches in pitch if you're talking stock bravo 4 blade props. ..And those are about .7 less than stamped size. a 28 is really about 27.3 "real" inches.

I wonder why some have 28 pitch props with the 496 and some have 30? Same drive ratio and I would imagine same x dimension. I tried a 28 bravo and was on the limiter at 3/4 throttle. I can easily spin 5100 with my 30 but my speed seems right in line with everyone else. Oh well I guess like everyone says leave good enough alone but sometimes we can't!!

Matt

I'm gonna run mine a few times more before changing to a 29-30. I'm still running 51-5200 rpms with the 28 B. This winter might add a supercharger and dana exhaust, if so I'll be changing props again, so I'll stick with the 28 for now.

If you are speaking of say around 2001 to 2007 single engine, step bottom 27 then the only difference from the 28 - 30 prop will be the gear reduction itself. Your numbers are exactly what the manufacturer claims on all the brochures we have regarding the 496HO boats (which i think all or most are of this vintage). 68 - 70mph stock. The 1.65 drives came with 28. The 1.50 drives came with 26.

That's why i can't understand why mine came with a 30 with 1.65 gears. everyone one else has 28's? How could the same package not even be on the limiter with a 28. Does mine slip that much more than the next one?

Do you have the performance report for your boat? If so, what is the X dimension. They fooled around with it a little bit (some had 19", some had 19.5") and some with higher X's had more slip and would spin a little bit more pitch, especially in cooler weather. On one of our 29 Fevers that had really high X, it actually needed a 1/2" to 1" drive spacer to get the prop to hook up decent. Otherwise, we had insane amount of slip, even with B1 props. Couldn't even get the boat on plane with a Hydro Q-IV ... it would just blow out the prop no matter what you did with the tabs and/or trim.

The performance report on our 2004 27 Fever showed X of 19.5" with 28P B1 RH prop at 5150 rpm (on the rev limiter) and 70 mph.

My 05 showes 1.65 ratio 19.5 X dimension 28P prop RH and 69 mph. I have seen 68. I tried a BB prop which was a 30P prop cut down and labbed. It did not perform as well as the stock prop. I don't think Fountain leaves much on the table. After trying the BB flop I gave up on any prop changes.

Interesting.......

I have done a lot more testing this season. I tried a BBlades labbed 28 P5X and it and was on the limiter at 68.3 mph but it was a nice cruising prop and I think a 29 P5X labbed might be the ticket especially with a loaded down boat. Tried the original 30 Bravo again with light fuel and got 71.4 on GPS at 5100rpm. I am kinda surprised how weight sensitive the boat is overall because real world testing isn't me bye myself with a quarter tank of fuel. Like others have said Fountain is pretty good from the factory and the 30 Bravo seemed to work the best so far. I am trying a Hydromotive quad 4 30 pitch tonight and will let you know if I can improve any numbers or even get on plane.

Matt

whatever ya do ya need to keep the 8.1 engine speed below 5100 the factory valve spring package doesn't like much over 5000 for long periods of time. when we used to run for merc I lunched a couple 8.1s for the same reason dropping valve springs and valves cause the test required 5100 rpm.

I have a 03 27 496 Mag HO bravo Ix running a LH BI 30p spinning 5000RPM in summer heat 70MPH all day. When it is cool and dry 5100RPM 71 MPH. The boat really likes chop, the more air you get under the boat the lighter it gets. Water conditions will make or cost a couple of MPH.

I agree 100% I heard the left hand prop actually is worth a little too. All I know is that when I pull up next to another 27 ft fountain with the same set up I want to be the one looking back not the opposite :-)

I have considered trying a 24 4 blade bravo RH on mine since it still has the factory LH

It's all about testing. I am a race car junky so I always like playing with different set ups in search of the best. I am having the blueprinting my bottom this winter in search of a little more also. Once you do 3 or 4 minor things to get 1/2 mph each time you end up with something a better than what you started with.

Matt

my 98 502 mpi im turning a LH labbed 24 hydro 67gps full fuel 2 people at 5100rpm best i have saw out of it.