Prop Help

[deleted member]

theses discussions just make me chuckle. doesn't matter how many of them i read over the years. for the most part, i've still got no fucking clue what you guys are talking about.

 

[ndfinfan]

^Thank you! When I bought the new boat couple weeks ago I just told the dealer to put a stainless steel prop on...trusted him to do the rest. Don't think in my wildest dreams I'd ever be able to notice much of a difference between props. Thinking about it now...maybe shoulda just let him put the cheaper aluminum prop on it!

 

[Velva_zv21]

Once you enter the prop world ther is no going back....muhahahaha

 

[raider]

theses discussions just make me chuckle. doesn't matter how many of them i read over the years. for the most part, i've still got no fucking clue what you guys are talking about.

here's the secret - if you are happy getting 1.5 miles per gallon @ 45mph at say 5000 rpm, leave it alone... if you would like to get down in the 1.2 mpg range, do whatever you can to suck out that last 1 - 2 mph out of her and run at around 6000 rpm...

 

[Velva_zv21]

^^^^^ C'mon its called smiles per gallon

 

[eyexer]

With the zv18 I always wanted to try a 19p tempest after trying the 21p and it being too much. ...i'm pretty sure I could've turned 6000 rpm with a 19p tempest, ther was something about that tempest that I really liked how the boat would grab while turning, hole shot was about the same as the enertia. And the tempest threw a rooster at WOT. Always fun when you can throw a rooster. Top end speed between 18p enertia and a 21p tempest was a +1 mph increase besides the 1000 rpms that I lost, figured I could raise the motor to get more r's but instead took the tempest off and then went back to stock and didn't mess with it anymore

anytime you want to try my 19 tempest let me know

 

[SLE]

here's the secret - if you are happy getting 1.5 miles per gallon @ 45mph at say 5000 rpm, leave it alone... if you would like to get better fuel mileage, more speed, a better performing boat, and have less wear on your engine, then do whatever you can to to get it right...

Here, let me fix this for you!

Seriously through, there is no downside to getting your boat operating in the RPM band where it's supposed to. If it'll run at the top of the RPM range when light, it will perform decent when loaded, you'll lug the engine less putting less wear and tear on it, your fuel mileage will be better, you'll have better hole shot and top speed, and a better boating experience. running the wrong prop and engine height is like ordering a $200 T bone a the fanciest steak house and putting ketchup on it!

Also, don't trust your dealer, many don't have a clue how to property set up a boat. Often times they just slap one on that is close or go with the manufactures recommendations which is usually an ok setup for the masses. However, everyone loads and uses there boat differently and getting it set-up specific for how you use and have your boat loaded will provided you a much more satisfying ownership experience. Heck, even within a given prop, such as a Bravo FS or any other, the manufactures have set them up to provided a decent experience for a wide range of hulls and performance characteristics. If you really want it dialed in, that's where a custom ground wheel from a reputable performance shop such as DAH or Croxton propeller comes in. basically you find the best stock prop and pitch for you boat, then have them balance and blue print the print the prop, they'll shave some weight, sharpen the leading edges, add cupping, re-pitch, and possibly flar the barrel or add additional vents pending exactly what and how you want your boat to perform. food for thought.

 

[Riggen&Jiggen]

I believe your main issue is motor height. In most cases you should run your motor a couple inches higher with a 4 blade than you would with a 3 blade. Best info I found for my set up was on Mercurys website. They have info on there for boat and motor setups. I have also emailed them with my boat and motor setup and they gave me some good info on pitch and height of motor.

 

[SLE]

I believe your main issue is motor height. In most cases you should run your motor a couple inches higher with a 4 blade than you would with a 3 blade.........

Not the case at all, motor height is more a function or set-back / hull configuration, prop diameter and tip cupping. A three blade tempest will run as high as any of the 4 blades that are used on our style of boats.

 

[Riggen&Jiggen]

Not the case at all, motor height is more a function or set-back / hull configuration, prop diameter and tip cupping. A three blade tempest will run as high as any of the 4 blades that are used on our style of boats.

That is not what the mercury racing dudes told me. Scott Reichow is the resident Mercury prop expert. I have a 3 blade tempest and a 4 blade FS bravo and the 3 blade runs like shit compaired to the 4 blade at the same motor height.

 

[SLE]

I'm going to divulge here a bit, setting up boats to run and run well works well with my Type A personality, lol.

Your right Riggen, you can't run every prop at the same height, there's a lot of factors both on the boat and the prop that will make a different. However, note that not all Tempest's are created equal and neither all Bravos but the bravos are more consistent. Just do a little reading about the A45, A46, A47, and newer A48 Tempest's. There's a vast difference in how they perform and they're all stamped with the same name, heck if i remember correctly, the A45s were even a larger diameter than the others. You could easily be on either on end of the spectrum with those two props and be running a poor A46 Tempest and a "Good" per-say Bravo. Once you start running blueprinted prop's it shows up quite quickly.

In theory, the Bravo's slightly larger diameter (about 1/4" in the pitches that we're talking about) would allow a higher engine height however, pending how much tip cup it actually has compared to the Tempest will determine how much bite it will actually hold when you start jacking the engine up. The other part that play's into it is how much stern lift the boat needs and most of our "Walleye" boats are fairly heavy in the back and need stern lift to control the bow in rough water. The Bravo's provide more stern lift through the use of a flared barrel. The barrel of the tempest is more strait and that prop is known to be geared much more towards bow lift. With the tempest running more nose high with the stern of the boat deeper in the water, you can often time raise and trim the engine pretty drastically especially if it has decent tip cup (again even from the factory they're not all the same, even in the same "A"series). The Tempest will be more efficient simply by nature if it being a three blade design and cupping, this is nothing more than basic physics. It's also why the Tempest will run less rpm at the same speed as an equally pitch Bravo. This isn't a guess, this is a fact. It is why they have to run 1 degree more of pitch on the Bravo than the tempest all things being equal. I've had two boat's where the Tempest would run higher than a Bravo, both of those boats ran extremely well. We'll just say it was a "good" tempest out of the box only made better with a little tweaking. still kinda pissed I let it go with the last boat.

Now, before you jump all over me about your Bravo running so much better than your Tempest, I'll be the first to say the Tempest is not always the best prop for our Walleye boats. We, more times than not, need more stern lift and better bow control. Heck, I'm running a Bravo FS myself, abiet croxtonized as they say. I am however running the Bravo because it's the best compromise between speed, handling, and economy on my particular boat. I would bet money I could get a Tempest to run faster on top end and a Rev 4 to handle better everywhere else, and this is exactly what I did on my last boat. Unfortunately I'm getting lazy in my old age and I'm willing to settle for something that's pretty good everywhere buy maybe not the best at anything. Food for thought.

I would be willing to bet if you dug into the details of this with Scott, you'd get some of the same information. It's where I've gotten some of my info along with with likes of John Janaky @ DAH propellers and Mark Croxton of Mark's High Performance Propeller. John will be the first to ask if you willing to have 3 or 4 props and switch them out based on your days need, lol. Obviously that isn't realistic for most, why you get sent in the direction of a prop that's a good compromise, aka the bravo! It's kind of mercurys standard ansewer these days after the reinvented it with the FS & XS nomenclature.

With that said, I'm sure I've dove done the rabbit hole and off track far enough to make most want to pull the trigger, so onward and back to getting Volmer setup!

 

[deleted member]

exactly what i was gonna say ^^^^

 

[buckhunter24_7]

Any update on this yet V?

 

[Vollmer]

57 with one guy. 3/4 fuel. Still only 5600 rpm.
They are mailing me a Bravo 1 19p to try. I’ll let you know as it progresses.

 

[sweeney]

jackplate time!!