Seven Marine 627 hp outboard

[Ed]

Originally Posted by Bigshrimpin

Plenty of videos to watch on youtube.

Twin 335's
https://www.youtube.com/watch?v=IXQM8kQkmjg
https://www.youtube.com/watch?v=YEN614JWm7E

Twin 2.5L 280 (FF's suggestion under 800lbs combined weight)
https://www.youtube.com/watch?v=4bVpV4VCGEo


Seven marine might be good option on some 35+ft center console, but it's really heavy and expensive. You could have 4 sets of 280's or 335's for the same price as one new seven marine outboard. None of these options are very functional on a flats boat or 23 seacraft hull as ggreeby suggests above . . . even though I love the sound of two Mercs singing together.

Tim - that video of the Talon with the 2.5L's is crazy. The motors were screaming. Did I see the tach right....pushing 7900 rpms? That video makes me want to send my twin 250 EFI's to Diamond for some tuning.

Did you ever buy "that boat" we were chatting about a month or so ago?

[flyingfrizzle]

Originally Posted by Ed

Tim - that video of the Talon with the 2.5L's is crazy. The motors were screaming. Did I see the tach right....pushing 7900 rpms? That video makes me want to send my twin 250 EFI's to Diamond for some tuning.

8k for a 2.5 can still be reliable. I plan to turn my pair up to 7 on the sc race hull. Many of the guys push them 10,000+ rpm.

https://www.youtube.com/watch?v=SR-KDqTpkks

https://www.youtube.com/watch?v=XZkxJJrB9ZM

Far as 3.0 liter efis check out simons motorsports...

The talon hit 115 mph, one wrong move or wake could be his last. Scary stuff, gotta have balls of steel. I just want to see 70 with mine.

[bgreene]

Talon's first one out to the fishing grounds for sure !! Good vid's.

Maybe a bit unrealistic to run a 23' Scepter at 100 mph +....... so, we'll stay conservative, and figure the lower powered 7 Marine 557 hp for about 75 mph.

This way we can " cruise " all day long at a placid 60.

[RUSTYNTABATHA]

very interesting thread...

[ericallen01]

Here's some amazing super V hull footage...

https://www.youtube.com/watch?v=XsWvWFc1dbA

[Fr. Frank]

I floated around the edges of high performance boating for a few years, occasionally dipping my toe in. Tim is right, high speed boating is EXTREMELY dangerous.

I began racing small "knee boats" (6'-8' class "A" hydroplanes) at the age of 7. I moved up to the B and C class at 9.
I quit dabbling in racing after stuffing a Gulf Wind Marine 30' Velocity at nearly 70 mph back in the early 80's off Ft. Lauderdale. Peeled the cap back like popping the top off a Tupperware. Analysis afterwards said I was probably about 1/4 of a second too early pulling the throttles back coming off a 3'-4' wave with a very steep backside. Result was dropping the nose and going through the next wave instead of over it. Driver broke his arm, I was just really banged up.

Any accident over about 45 mph can easily be fatal to everyone on board. I helped recover the body of a man who snap-rolled his 24' Martini at about only 40 mph right in front of Spencer Boat Works due to a broken steering cable. His girlfriend survived with a broken neck, his teen-aged son had broken ribs.

This doesn't mean going fast on the water isn't fun, the idea is to make it as safe as possible. I've rigged a 23' SeaVette with twin 235 Evinrudes for a customer, and we actually dropped the engines a bit to slow it down and make it less squirrely. I've also rigged a 2.4L Bridgeport on the back of a 20' SF that would easily top 60, but was pretty hard to control.

SeaCraft is a great hull for going fast in rough water - up to a point.
I know for a fact that the Seafari 20' handles very well in the 50-55 mph range. But I sure wouldn't want to go any faster than that! At 53 mph the Seafari is fairly dancing on the surface of the water, and at 55 it's just starting to want to fall off to one side or the other, as it's now up on the narrowest planing surfaces. That, by the way for those of you who don't recognize the signs, is the beginning of a chine walk, which can easily become the prelude to a snap-roll, where all passengers exit the ride suddenly.

Please remember that most offshore powerboat races with 21-25' V-hulls average less than 60 mph across the course/duration of a race. Occasionally you'll see a calm course where the average speed gets up closer to 70, but that's actually not common.

SO rigging a boat to go fast and then going fast = Fun! Rigging a boat to go stupid fast and then being stupid = not so much.

[bgreene]

Frank except for the info on race type boats, this thread's mostly for fun, not reality....

The 7 Marine outboard weighs approx 1,000 lbs...... not really appropriate for an old 23 boat.

[RUSTYNTABATHA]

to float the 657 .... twin engine hermco with EXTRA setback... for the flotation...

[Briguy]

That 627 would float very nicely on the Stretched 23 hull. It has twin 175's which are damn close to or at 1000 lbs.

[Bigshrimpin]

I'd rather have one of these!!! Great idea if they hold up.

http://www.screamandfly.com/content....-Racing-Engine


https://youtu.be/c2opyvpBY8g