electrical1

looking to re - prop my 42' excalibur eagle after installing new 454 engines with procharges approx. 700hp ea.
is houston prop still the recommended prop supplier on this site. if yes does anyone how to get in touch with them.

articfriends

iTrader: (1)

Did you finally get the boat to run without issues? I'm glad to see you haven't had any post lately about blown motors,maybe all that bad luck is behind you,Smitty

electrical1

Beleive it or not i just got in the water, hasn't been the greatest experience. boat seems to be running good. took long enough. season is almost over here. now i need new props the new ones i bought last year just spin out now that I have so much more hp. I haven't seen any post lately about houston prop for a long time thats all you heard about on this site for props. is everyone still having good experience with them.

Revd Up

There are several prop "Guru's" on this site that can help you. I use DAH Pro-Pellers and have had great results. Knowledgeable , easy to work with,and quality workmanship. Call John or Jeff Janaky at (262) 534-4440.

electrical1

thanks I'll try them tomorrow. I'm looking for someone who can give me some good advice. Since there are a lot of unknown factors. Motors are supposedly putting out about 700hp ea., but boat is very heavy 11500 lbs. dry approx 15000 lbs loaded. V bottom. I have 15 x 21 on there now but they blow right out. I don't know the top end rpms because rev limiters shut down at 5400. props blow out at about 3/4 throttle. looking for someone who can get me close with a little to spare so props can be reworked if necessary

tcelano

I'm assuming that you have 1.5:1 gears, in which case 21" of pitch isn't nearly enough to do the trick with 700 hp on tap. In fact, even loaded to 14,500 lb, you'd only be using about 450 hp per engine at redline, and only be travelling at roughly 58 mph.

Computational Results
Your boat's computed performance is as follows:

SPEED(mph) ENGINE RPM REQ'D BHP AVAILABLE BHP PROP SLIP WETTED LENGTH(ft)
25.00 2921 287 801 36.56 22.54
26.00 3004 303 829 35.78 22.84
27.00 3088 320 858 35.09 23.21
28.00 3172 337 886 34.42 23.43
29.00 3252 354 913 33.75 23.47
30.00 3334 372 940 33.12 23.55
31.00 3413 388 966 32.46 23.41
32.00 3482 399 988 31.66 22.78
33.00 3557 414 1012 30.99 22.43
34.00 3626 426 1033 30.26 21.86
35.00 3701 442 1057 29.65 21.55
36.00 3771 454 1078 28.99 21.02
37.00 3841 468 1098 28.35 20.52
38.00 3917 485 1120 27.82 20.27
39.00 3988 499 1140 27.23 19.80
40.00 4058 514 1159 26.66 19.36
41.00 4129 529 1177 26.11 18.93
42.00 4206 548 1196 25.67 18.74
43.00 4277 564 1213 25.17 18.34
44.00 4348 580 1229 24.68 17.96
45.00 4419 596 1244 24.21 17.59
46.00 4497 618 1259 23.85 17.44
47.00 4568 635 1272 23.41 17.10
48.00 4640 653 1284 22.99 16.77
49.00 4712 671 1295 22.58 16.45
50.00 4784 689 1305 22.19 16.14
51.00 4856 708 1313 21.81 15.84
52.00 4928 727 1320 21.45 15.55
53.00 5006 751 1326 21.17 15.47
54.00 5079 771 1330 20.83 15.20
55.00 5151 791 1332 20.50 14.93
56.00 5224 812 1333 20.18 14.68
57.00 5297 833 1332 19.87 14.43
58.00 5369 854 1329 19.57 14.20
58.42 5400 875 1324 19.28 13.97

I'd recommend trying a 15.25 x 27, assuming that you are making 700 hp. That will get you more like 75 mph:

Computational Results
Your boat's computed performance is as follows:

SPEED(mph) ENGINE RPM REQ'D BHP AVAILABLE BHP PROP SLIP WETTED LENGTH(ft)
25.00 2495 316 658 42.22 22.54
26.00 2559 335 679 41.38 22.84
27.00 2626 354 702 40.63 23.21
28.00 2692 374 724 39.90 23.43
29.00 2756 392 745 39.18 23.47
30.00 2820 412 767 38.50 23.55
31.00 2881 429 788 37.78 23.41
32.00 2934 440 806 36.92 22.78
33.00 2991 455 825 36.18 22.43
34.00 3044 466 843 35.39 21.86
35.00 3102 481 863 34.72 21.55
36.00 3155 493 880 33.99 21.02
37.00 3209 505 898 33.29 20.52
38.00 3268 521 918 32.70 20.27
39.00 3322 534 936 32.05 19.80
40.00 3376 546 954 31.43 19.36
41.00 3430 560 971 30.83 18.93
42.00 3490 578 991 30.34 18.74
43.00 3545 592 1008 29.78 18.34
44.00 3600 606 1025 29.24 17.96
45.00 3655 621 1042 28.72 17.59
46.00 3715 641 1061 28.32 17.44
47.00 3771 657 1077 27.83 17.10
48.00 3826 673 1094 27.36 16.77
49.00 3882 690 1110 26.91 16.45
50.00 3937 707 1126 26.47 16.14
51.00 3993 724 1141 26.05 15.84
52.00 4049 742 1156 25.64 15.55
53.00 4111 766 1172 25.34 15.47
54.00 4167 785 1186 24.96 15.20
55.00 4224 804 1200 24.58 14.93
56.00 4280 824 1213 24.23 14.68
57.00 4337 844 1226 23.88 14.43
58.00 4393 864 1238 23.54 14.20
59.00 4450 885 1250 23.22 13.97
60.00 4507 906 1261 22.90 13.74
61.00 4564 927 1271 22.59 13.53
62.00 4627 956 1282 22.38 13.49
63.00 4684 978 1291 22.09 13.28
64.00 4741 1001 1299 21.81 13.08
65.00 4799 1024 1306 21.54 12.88
66.00 4856 1048 1313 21.27 12.69
67.00 4914 1072 1319 21.01 12.51
68.00 4971 1096 1323 20.76 12.33
69.00 5029 1121 1327 20.52 12.16
70.00 5087 1146 1330 20.29 11.99
71.00 5144 1172 1332 20.06 11.82
72.00 5202 1198 1333 19.83 11.66
73.00 5260 1224 1332 19.62 11.50
74.00 5319 1251 1331 19.40 11.35
75.00 5377 1278 1328 19.20 11.20
75.39 5400 1306 1325 19.00 11.06

I don't have all the variables necessary for an accurate prediction from the info on the thread. Please visit www.speedboatperformance.com, and you can use the online numerical prediction program to help guide your propeller selection. With a boat this heavy, most of the Bravo style propellers are going to have less diameter than would be ideal. You could try running 5 or 6 blade props to get a bit more bite, and get those slip numbers down from 20+ percent. If the boat is equipped with SSM's, you have a wiide range of diameters, up to 18" from which to select. I'm guessing, though that it's Bravo's, and I don't predict a long service life given the power and the boat weight unless you perform some upgrades on them.

custom29scarab

Anyone tried this speedboat performance .com?????
I would like to see predicted vs actual results on the 05 top gun? I couldn't find it did anyone else?

articfriends

iTrader: (1)

Dave,buy a pair of 4 blades from a company with a prop exchange program ,probably 24 pitch and go from there. my boat started w/23 pirch props and after supercharging it would blow 3 blades loose above 1/2 throttle. i first started with a 26 pitch and it worked good around 5000 rpm's w/502 m-3 at 6 psi. W/prochargers and 454's your probably closer to 625Hp unless you are running tons of boost a aftermarket heads,Smitty
You can even call me if you like 989-823-7319 and I'll go over your set-up before you call a prop place