JensColbinSwede

Did the prop have problem to "grip the water" with the 2inch shorty? which prop did you run with at the time?
Speaking of props, it's interesting that you run that god with a tempest. If I understand right, it's made for outboard motors.
I think you're right about the gunnel knots, when I see your pic. My boat is going lower in the water, probably because of wrong prop.
Do you have a lot of trim when running at max speed?
I need to trim much to get the speed, but the boat starts to go like a snake, likely because of the bad angle of prop with a lot of trim.

River_Runner

We tried a few different props with the shorty on but never could get on plane. Yes the tempest is made for outboard motors, but on a limb we tested it and it is the absolute best for the boat. Next best was the 27 mirage. When it comes to trim at top speed I just go by feel. Do you have any steering on your boat? Single hydraulic or dual ram assisted? If not that may be where you are getting that "snake" driving your talking about, because the slop in the assembly is wandering back and forth. I am turning the 27 tempest prop 5800 RPM depending on the load I have in the boat.

JensColbinSwede

I installed a full hydraulic steeing with one cylinder last spring. The steering became much better but snaking is still there.
I'll try to find a Temest prop with 25P (since I have 1:3 gear).
But I would also like to test a shorty. I mean, if I can get it to plan I think it will run great.
...but it has to wait for next summer... :-)

BUP

River on your intake manifold change from Dart single plane to the Sniper Jr. did you see any improvements ?

Cole-One

Intake was good for 30 hp and it moved the torque range up the power band so it pulls strong in the upper rpms (5,800-6,000)

BUP

Really just an intake change alone was good for that hp 30 hp or was something else done here ? . I would never have thought that much swapping the dart intake out alone would produce 30 hp increase.

Cole-One

We had Dart Iron Eagle 308's on the 509 with the Dart intake then went to Edelbrock's marine head with the Profiler intake the flow numbers were very close on both heads. The first set up did 601 hp the next made 651 hp we were after the 70 lb weight savings from the iron to aluminum and ended up with some extra hp. The engine shop we use has seen 25-45 hp on a wide range of engines from drag,mud,pullers and boat engines Randall's Racing & Machine 804-796-5155 ask for Rodger

beaver 3

my block is at the machine shop now. building a 489 with forged eagle crank and rods and 14cc dome diamond pistons, gm 781 casting heads 119cc with 2.19 stainless intakes and 1.88 inconel exhaust valves, throats machined and casting smoothed. .578/.618 231./235 @.050 on a 112. havnt decided on a carb and intake but im thinking holley 800 and an airgap. ill be running my take off aluminum 496 exhaust. ill possibly have to modify or make my own tailpipes. hoping to make 450 and run 75 when its all settled out.

because of money issues im going to have to run an alpha drive this summer and not be able to open the boat up. its going to be terrible. i already have a bravo lower half. i just need the rest of the puzzle.

anybody else doing anything this winter?

Cole-One

Sounds like a great project I hope it runs well you should be able to open it up just dont wack the throttle coming out of the hole or anytime for that matter....roll in and out of it. It will last for a while I have a friend with 500hp on his its been living for 3 summers.

Cole-One

We are adding cubic inches looking to gain torque and hope we can run over 90 with ease, we'll post dyno pic's soon...