500hp prop

[donzi2287]

anybody with a 500 h.p. that has a recommendation of a prop size? my new motor should be in next week!

thanks for any help

[chappy]

Need a little more info; hull, drive? If you do a search above, there are probably some threads with prop recommendations that match your setup. Good luck and keep us posted with results.:thumbsup:

[p729lws]

If you're still in Pensacola and still have the 22 Classic and it's a Bravo/Alpha drive I have a Power Tech 26 pitch four blade you can try which should be pretty close.

Dan

[Cuda]

I was going to put an HP500 in my 22, but never did (ran out of funds), but I was figuring something in the 27 inch diameter.

[CHACHI]

I was going to put an HP500 in my 22, but never did (ran out of funds), but I was figuring something in the 27 inch diameter.
Joe.............pitch.
You are up way too early.

Ken

[Barry Eller]

Joe.............pitch.
You are up way too early.
Ken
Too early...or too late?:wink:

I am around 500 HP, I have 3 props, 25" Turbo, 25" Balistic worked to around 26", 23" Hydromotive Quad IV for crusing and rough water. King Cobra drive has 1.43 gear ratio.

Are you in Pensacola?

[BigGrizzly]

Standard driv and 50 HP on a 22 classic won't turn a 27 pitch. I sell props and can tell you that every combination is different, not by much, but different. I helped design that power tech prop it is a good starting point. It was designed while I worked at Honda Marine as a bass boat application and was suppose to be an exclusive until Power-Tec got greedy.

[VetteLT193]

donzi2287 is my brother.

1987 22 classic, HP500 with CMI exhaust and the updated cam (731 I think?) Barry Grant Carb, Bravo 1 (1.5:1). Not sure on the X dim but if it helps it was a stock Alpha 1 454 boat and the bravo went in the same hole as the Alpha.

[donzi2287]

anybody with a 500 h.p. that has a recommendation of a prop size? my new motor should be in next week!
thanks for any help its a 22 classic 1987 with a bravo one drive 1.50

[p729lws]

If you want to try my 26P Power Tech let me know. I'll bring it to the office if you can get down town during business hours.
Dan

[VetteLT193]

If you want to try my 26P Power Tech let me know. I'll bring it to the office if you can get down town during business hours.
Dan

he's in the Key Largo now :(

[p729lws]

Who's putting in the new motor and is it a 500 efi? I thought he already had a pretty new motor.

Dan

[Cuda]

Joe.............pitch.
You are up way too early.

Ken
I still had to read that twice! :)

You're right on both counts. I woke up at 2 am, and once I open my eyes, it's all over. :garfield:

[VetteLT193]

Who's putting in the new motor and is it a 500 efi? I thought he already had a pretty new motor.
Dan

My brother is putting it in his 22. It is HP 500 Carb.

Opportunity knocked with finding the HP engine so we jumped on it and a drive package together from Cuda.

[roadtrip se]

with a 26 TXP three blade from Precision and go from there.

[VetteLT193]

What I'm confused about is stuff I read in other places, like this thread: http://www.donzi.net/forums/showthread.php?t=53175

That one is saying a stock 496HO 22 classic can spin a 27" prop. One would think an extra 75 HP would easily require more than 27".

Just curious as to what the differences are, or ?

[blackhawk]

What I'm confused about is stuff I read in other places, like this thread: http://www.donzi.net/forums/showthread.php?t=53175
That one is saying a stock 496HO 22 classic can spin a 27" prop. One would think an extra 75 HP would easily require more than 27".
Just curious as to what the differences are, or ?

I can't see why a HP500 wouldn't turn a 27 if stock 502s and 496s are turning 25s. That link is for my prop and it runs great on my Pantera and I know a Classic is faster with equal power.

[BigGrizzly]

A 27 pitch on a 22 with a bravo and a 1:50 drive at 5,000 is about 80 mph. It takes a good 500Hp to do that. There is a monumental difference between a 25 and a 27 pitch in relation to pushing water. It is getting closer to the paddle wheel effect. Vett, your not confused they are.

[blackhawk]

A 27 pitch on a 22 with a bravo and a 1:50 drive at 5,000 is about 80 mph. It takes a good 500Hp to do that.


Maybe I am confused but wasn't this thread asking what prop is good for a 22classic with a 500HP? LOL

[roadtrip se]

Real world results gathered right here on HP classics say....

Dr. Dan run's a 26 TXP, but he has a odd ball gear ratio on the King and a very stout, or as Haver calls it "stock", rebuilt 500.

Donzi shipped the SE with a 25 Mirage, although they were labbed.

I run a -2 shortie and the sweet spot for me is in the 27-28 inch pitch range.

Mick's results with the 496 Raykar kit, mimic mine with the -2 shortie set-up.
He is turning a 28 TXP.

Byron turned a 25 pitch Mirage on the regular bravo drive with the 540.

Sooooo.... search the internet all over and justify whatever you would like,
but when you are done, I would start with a 25 or 26 stock three blade, like the TXP and the Mirage, and see what happens.

By the way, I am still waiting to see a stock x-dim 496HO boat run with me at 80. It may happen, but it hasn't yet. I have run 87 in a river current, but you don't see me post this as my top number, because it was a one timer...

[blackhawk]

A 25 Mirage + will be good for mid to high 70's.

A 27 will lower the rpm and maybe give you a tick or two.

A labbed 27 will put you in the sweet spot and get you to 80 if the power is there.

[Cuda]

Just for comparison sake, Catch runs a 31 pitch with his procharged 454. O can't remember the make. Maybe Gina will type it in for us.

[blackhawk]

There is a difference between 500HP and an HP 500. ..
26 TXP...

Good point...but it was posted that it was a HP500 so I assumed it was the a blue motor.

[blackhawk]

So, it's about what, 460 HP?
Pinky's running a Throttle Up prop...

Stock HP500s dyno about 510hp at the crank.

[blackhawk]

EFI's dynoed @ 470 @ the prop, allegedly 10 hp more than carbed.... Crank HP is misleading....

They were RATED at 470 at the prop. But most actually dynoed in the 510hp range at the crank. EFI's were a little more stout, about 5-10hp more. Propshaft hp is misleading. :D

The factory race motors(HP500, 500EFI and 525EFI) always dyno higher than rated. While the standard merc motors(454MPI, 502MPI, 496HOs) dyno a little lower than rated.

[donzi2287]

so i have a mirage plus 25. is that good enough? i spun it at 42k in and 48k trimmed out. now i am going from a 454/425 to a 502/500. plus i have that cool and bad to the bone cmi exhaust. demon 825 carb to add. what do you think?

Eddie

[blackhawk]

Prop HP is what moves the boat.. Much like in street racing, you can 10,756,8543.3 hp at the crank, but it's what gets to the road that counts :D :D
So, what did the carbed vs efi motor actually deliver at the prop? Most folks say a 10% drop through a bravo right? Brings a 520 HP efi motor to 468. Merc rounded up :) ;) :D

I agree. Bob from FTM did a nice post about loss and I think it was about 8%so you are probably close at 470-480pshp. But what many people don't realize is that is about 75-80hp more than a 496HO.

[blackhawk]

so i have a mirage plus 25. is that good enough? i spun it at 42k in and 48k trimmed out. now i am going from a 454/425 to a 502/500. plus i have that cool and bad to the bone cmi exhaust. demon 825 carb to add. what do you think?
Eddie

If you have a M+ 25 that is a good start. Hopefully you will spool it up to the rev limiter! :D If so then go bigger.

[VetteLT193]

I was trying to factor in the exhaust and carb. I know he gained a solid 200 RPM from the CMI exhaust on his old 454 425 HP engine. And his old exhaust was GIL offshore (dry)

So, factoring in that Merc had GIL wet exhaust as part of the rating, plus the better cam and carb he should be a stout HP 500

[donzi2287]

scott just want to thank u again! i still have your come alongs anyway.

i will have the motor installed this weekend and will run it the following by the time i get it all done, i can't wait for it to run though!!! i'll c u next week for sure!!
Eddie

[donzi2287]

blackhaawk ur right!!!! i hope my prop is too small.

[Dr. Dan]

:smash:Well.... I will chime in... first I would run some numbers in these Prop Calc Websites

http://www.go-fast.com/Prop_Slip_Calculator.htm

I believe Bronson Propellers http://www.hillpropellers.com/

has a more casual calculator... if you figure 10% Slip you may be plus or minus a few points but it will be good enough to give you a "BaseLine"

I do have a 1:43 Ratio King Cobra - I had originally a small 330 Horse 454 from the factory.... during a non-drug induced comma I was unduly influenced by a few folks here that will go nameless ( Ted, Chris Allard, Poodle and Roadtrip) to go Blue, mate it to the King and make the King draw water like a large Bravo...

To date it has performed flawlessly and to alot of peoples amazement - not the least of which are the Folks I never mentioned in the brackets above.

I am running an admittedly very healthy HP500EFI with E-Top CMI's with Custom Tails - Wet and Thru Hull with no mufflers or baffles or anything. The boat is a turn key 80mph ride... it will go faster... but why? As is it will run with 97% of the Classics on this Registry... its professionally maintained, it was professionally built... with the 454 I ran an Elephant Ear 3 Blade Turbo the boat did 59 mph.

:wavey:When we dropped the EFI in there, we started 2" up with a stock 3 Blade 25 Turbo - later I got a 25 TXP, I did buy a regular 27" 3 Blade Turbo and I could only turn it about 4400rpm, I went to a 26 TXP and its the choice prop now.

The boat runs 80mph @ 4950 rpm and I have never hit the rev limiter at 5250, so if I get bored and wanna Lab a 26 or a 27 or a 28 3-Blade and gain a few hundred more rpm - I am confident the boat will run faster than 80 mph.

The King Cobra however does not require advanced stain your friggin pants over trimming to hit 80 mph. It will do it at Neutral Trim, dragging Tabs at a parallel to running surface level and with 55 Gallons of fuel with Liz and my Fat Ass driving.:spongebob:

So I know being conservative and hitting 80 mph I have to believe the boat will run 2 to 4 mph faster if I got a few more rpms, lifted the Tabs Fully, and trimmed the Drive alot more. So why don't I do that? Because I don't have to... the King Cobra does not need to be over trimmed to hit the desired speed...I can run it safe and with zero chine walking stable as if it was on a Rail as they say...and it frustrates the living Chit out of a few folks... but they respect its performance, and my conservative and safe operating demeanor. I spoke with the folks of Precision Props at the Awakening this year and they suggested other than getting a few more rpms by labbing a prop they would not change a thing for my boat, because I am not having handling (Bravo) issues I would gain nothing with a 4 Blade on the King Cobra, because its stable as hell now? I do want to add steering but again one thing at a time.

:beer:I have a tremendous amount of respect for my boat and what its capable of... I don't abuse it, I don't run it if I 've been drinking, or at least not very fast(45 to 50) if we were at the Sand Bar all afternoon. And I like that... I want my passengers and friends to feel safe around me.

I don't have to drive like a friggin lunatic to prove to anyone that my boat is fast, or quick or anything... its all that and a Bag of Chips. Each hull is different... try a 26 TXP 3 Blade. See what your rpms are at different speeds, record them, have a GPS or get a GPS Speedo. Don't run in a current if you want accurate readings, take an average. I did all of that and I was not shy to listen to Poodle , Grizzly , Todd and Ted and many others here who have helped me develop into a much better driver of my own boat.

There is no substitute for "Seat Time" ask Mick ( Hot Shot ) ask Undertaker, ask Air 22 or anyone... run your boat, learn your boat.... listen to others who know what they are talking about, you get what you pay for... don't go cheap, do it the right way and you will be a happy camper....it doesn't happen over nite... it all takes time. Do small incremental changes after you have established baseline performance numbers, borrow props... it is the fun part.

Remember No Matter What - There is always someone faster than you are, be Safe and Enjoy your Donzi.... its the time of your life!:salute:

Good Luck

Doc of Semi Unorthodox HP500 EFI's :tase:

[BigGrizzly]

Listen to Doc. He breaks down less and enjoys his boat more. Rome wasn't built in a day and neither was Hoboken NJ. Only make one change at a time. One thing I will say and is indisputable, seat time= MPH, no one can drive my boat faster then me and I can't drive Doc's boat faster then him, this is fact.

[roadtrip se]

Listen to Doc. He breaks down less and enjoys his boat more. Rome wasn't built in a day and neither was Hoboken NJ. Only make one change at a time. One thing I will say and is indisputable, seat time= MPH, no one can drive my boat faster then me and I can't drive Doc's boat faster then him, this is fact.

I don't agree on the one change at a time theory, just get it done and get it over with and get back to the water. I did. At least with the major stuff like the engine, drive, and steering systems.

BUT, don't expect to be the King of the Water, first time out, or the second, or the third. Ted taught me this lesson first time out at Eufala when I showed up with a boat rigged very close to his and he stomped me resoundingly. Things are going to need to be adjusted and tweaked, including your ability to respond to what the boat is telling you. This is where the incremental improvements come into play.

Prop testing is just part of this process.

You want to see a major exercise in frustration, and quite entertaining to watch actually, put Gerometta behind the wheel of the RTSE and sit back and listen as the explicitives roll from his lips. AND I would put Gero up against anybody as one of the finest drivers of a Blackhawk that I have ever seen.

Live and learn.

[Air 22]

Test and test again til ya find what YOU LIKE!...different drivers, skills, hulls, props, ego's, engines = varied results:smash:....Nothing beats SEAT TIME:wink: Its all in the name of FUN....and getting Wet...::beer::

[The Hedgehog]

Seat time and prop testing. Nothing like experience, your experience.

I know it is not a 22 but I am constantly learning about dialing in a boat.

I am in my second season with my X-18 and just finally got a LH Turbo. The boat loves it. Before the best I did was with a RH Mirage plus. I got 71. My boat is a LH configuration but figured that it did not matter much as long as you are on top of the water. That is somewhat true but I was bound and determined to switch to left. I did that at the same time went to a Turbo. All I can say is wow. Gone is the mid range bounce and high end chine walk. The lower mid range handling is great and at high end the boat felt nicely attached to the water but not glued to it. I had a bunch going on so I did not get to GPS it. I did pick up 4-5 mph over the borrowed Bravo I I was using. When I do GPS it I will post the final results.

It would have been easy to just find a LH Mirage Plus and say that since they use those at the factory it is good enough. I spent a little extra time and seem to have ended up finding something better. You should certainly take these guys up on the offer to try some verious props.

Thanks for hooking me up with the props Mr Fixx.

[RickSE]

As RT mentioned my stock 500EFI 22C came with a labbed 25P Mirage +. I usually boat at 3,600' elevation and can turn the 25P to 5200-5300 RPM's. When I go down to lower elevations, <1,000', I hit the rev. limiter.

I'd start with a 26P or 27P and go from there.

[donzihunter]

You and I should talk. I have an 88z22 and about 3000 in props. I just went thru this conversion from a 350 to a 510 with a bravo. Call me if you like.

210-889-2559

Eric