Classic SeaCraft Community - My brothers new SeaCraft Tsunami

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- - My brothers new SeaCraft Tsunami (http://www.classicseacraft.com/community/showthread.php?t=25542)

Yeah this is 1.5 ratio bravo 1 it had a 260hp with mirage 19p on it which we have not tried yet.

Beautiful boat. You and your family definitely have the South Coast Sceptre market cornered. ;)

Quote:

Originally Posted by bigeasy1 (Post 216908)

I tried several props and ended up with a 15-1/2" x 17 pitch Mirage ss prop.It is about as close as I can get to being the best performer.
My Tsunami has less ponys(350 ci 260-275 hp) than your brothers however,and My outdrive is a Mercruiser Alpha with a 1.65 gear ratio.

Different boat but here are my first set of numbers.

I was able to pick up a Mirage + 3 blade 21 from blue heron...I believe it is a 14 3/4 diameter.

All the numbers are gps smooth water and a mile run through each rpm range. Boat had one person and approx. 40 gals. of fuel. No trim was used (motor and tabs).

Let me say this: instant response and torque on demand. Pulls hard all the way.

Motor is new less than 3 hours in the test. I have a feeling that I may be under propped when the stroker loosens up. Not by much.

rpm- gph- mph- mpg-

1000/ 2.1- 6- 2.8

2500/ 6 - 23.5 - 3.9

3000/ 9 - 29 - 3.2

3500/ 12.5 - 34 - 2.7

4000/ 14.1 - 42 - 3.0

One quick blast up to 50 @ 4900.

I hate to say it, but that was 2 summers ago...hopefully new numbers coming soon.:D

Terry,

FYI, Bob liked to cruise the Unohu at about 20 kts/23 mph and 9"Hg vacuum. Interesting that your optimum cruise speed appears to be about the same as his! However his mpg with a 260 hp Mercruiser was somewhere between 2.5 and 3.0 mpg, with a Bahamas type load.

What's the rated rpm on that stroker? Denny

Quote:

Originally Posted by Bushwacker (Post 216967)

Terry,

What's the rated rpm on that stroker? Denny

I believe it is 55-5600 rpm.

383 Stroker:

SPECIFICATIONS:
Horsepower: 350hp @ crankshaft
Torque: 390 lb/ft @ 4,200 rpm
WOT Operating Range: 4800-5200 rpm
Engine Configuration: GM Small Block V-8
Displacement: 383 ci / 6.3L
Compression Ratio: 9.0:1
Idle Speed: 600 rpmThis engine comes with a 3-YEAR MerCruiser factory warranty!