OUTLAW EAGLE MANUFACTURING

[under ground]

Got a 2007 21' northwest jet 350 marine power and 212 with a 2.4T when trying to run at 30 mph have to run at 3600 rpm and boat is empty. When running at 3400 rpm going about 25 mph. just wondering if a repower to a 383 will give me the bottom end torque to run at lower rpm and stay at the 30 mph

[dixopr]

What is the matter with 3600 rpm? Not sure what a 2.4 will do at WOT but should be near 4200 or so??? You could switch to a bigger impeller to drop your cruise rpm but it won't change your fuel usage much if at all. what is your full throttle speed? What is your minimum planning speed? More engine give you faster speeds and a better hole shot but the hull will have similar cruise speeds and minimums. The big block guys don't burn that much more fuel unless they are at full throttle.

[riverboater]

A strong big block and a 4.0 blade will give you everything you are looking for. And amazingly it won't burn any more fuel at the same cruise speed.

[riverboater]

I swapped out a 5.7 Kodiak and 773 for a BBC and Scott 852, at the same cruise speed the fuel burn is the same or better. Of course with the added performance I tend to use it and yes you can burn the fuel up if you want to. With the upgraded power and pump I have not yet found the load limit.

[dixopr]

Riverboater, what BBC did you swap in what kind of Boat? what kind of numbers are you running now? I'm not familiar with the older Hamilton's so I can't compare.

[riverboater]

I built the boat myself, 16ft 18 degree with step tunnels, I swapped in a healthy 500 cu in custom BBC with the 773 Hamilton first, and then found and swapped the bigger pump. The bigger pump made the most difference, your 212 is a good large impellor pump, just needs more blade and the power to turn it. Yes if I put an AT309 pump in I would likely pick up some serious top speed. The scott gives me just over 60 mph with no end to the load it will lift, ran out of ropes and skiers before it ran out of pull. Standing room only and it jumps on plane in a couple boat lengths.

[dixopr]

Cool boat. Can you run slow with the Scott in that hull?

[riverboater]

Yes, the scott has serious up and down tilt angles. You can hold a sloppy plane well under 20mph. Problem I found with tilt down hard at slow speed in shallow water is serious damage to the river bottom. A friend pointed it out after following me through a shallow stretch. I literally dug a trench a foot deep and as wide. Learned to get the nozzle up near level as soon after take off as possible.

[coho dr.]

Sell the 2.4 and buy a 2.9 or 3.4 impeller. The swap will lower your cruise rpm . And also your wot rpm. This is a no brainer here.