Re: 24 ft SC
 

yes, mcgillicuddy we hit 69.6 or 69.8 a couple years ago on a gps on my 20. But water has to be perfect. I dont have gps on board anymore so i dont know what it runs now after a few years of hard running.

Re: 24 ft SC
 

Back in February 1984, I rigged a SeaVette with new twin 235's prepped by 2nd Effort, including nose cones and low-water pick-ups, and we added K-planes. Both RH rotation motors back in those days.

We could get an indicated 71-72 mph on an AutoMeter marine speedometer. This was achieved running early in the a.m. while it was cold. We had projected 74-75 mph, but we were unable to achieve that as rigged. Speeds later in the day fell to 68-69, and further loading 4 people and full fuel late in the day dropped it to 66-67 mph. Fuel consumption was about 51-52 gph at WOT.

The other boat we were rigging with 2nd effort motors at the same time was a 25'5" Checkmate with identical engines. The balsa-cored Checkmate weighed nearly 1100 lbs less, but was only 4-5 mph faster, and in fact had to run slower offshore in 2'-3' seas. With a good throttleman, the SeaVette could run WFO (64-65 mph) even in 2'-3' seas.

Re: 24 ft SC
 

Fact of the day:

There were only 52 23' SeaCraft "SeaVettes" ever built. They started in 1978 and ended in 1979. So it's a pretty rare boat.

Re: 24 ft SC
 

Yeah, but the original SeaVettes were 27' long. There were three 27' (yes, twenty-seven foot) Seavettes built by Carl Moesly as prototypes for the US government, back in 1968-'69. All three were powered by twin big-block Mercruisers. Carl didn't remember the installed HP. Because they were prototypes, they didn't make the official "production" inventory list. I understand the differences in the prototypes was in the setup for armaments. More than that Carl was not allowed to say.

I know what happened to one of them over in Africa. I'd love to know where the other two are now.

Re: 24 ft SC
 

Yea, I've seen 65.3 GPS with mine. I'm making 502 HP at the flywheel, probably around 475-480 at the prop. My outdrive is too deep and I could probably get a couple more MPH with the right drive height. I don't believe the 70 MPH with twin 200s. The Seavette is a heavy boat and I believe that it would take 600+ HP to get it to run 70 MPH. :D

Re: 24 ft SC
 

I would guess high mid 50's with that rig . . . unless the motors had some work done. 2.4L powerheads can produce 250hp + with some mods and at 363lbs each you might get into the 60's. Those motors in stock form will cut out at 5800rpm because of the idle stabilizer/spark advance module which means you'd have to be running at least 28pitch choppers to hit 70 with stock 1.87 ratio lowers.