Kind of board at work and want to see how good you guys are.

Here's the boat:

96 31 Scarab "Thunder" it has every option, shore power , fresh water, pump out head, full hydraulic steering....etc.

1:5 Bravos

Here's the power:

(2) 350ci 2 bolt mains, stock crank Lunati rods, Stainless Marine exhaust, non ported Canfield aluminum heads, with big solid roller cams. They have just been freshened after 350 hours of use.

Guess how fast

how much hp?

what kind of bottom?

boat weight?

my guess(provided there are no curves thrown my way) is 69mph.

how fast does a sea tow boat go??

Based on a slightly modified p-29 running 78-80 with about the same engines/power,and a 31 is only 3-5 mph slower with the same power, I'll say 75-77 best. 73 on it's worst day

well you have to remember the 31 scarab is basically a 33 scarab without stepa and intergrated platform. Plus I have never seen a 31 scarab with smallblocks? I say about 60

Dan

First the motors have never been dynoed so your guess is a good as mine.

Second, a 31 Scarab is a deep V , no steps or pads I have no idea how much the boat weighs


Third , Audacity what lanquage are you speaking ?

Fourth , this is just for fun

Frank , you are pretty close

By the way Joe that would be my boat (at the moment) going as fast as the sea tow boat

80 on the Interstate, but much slower around town.

Okay you guys ,
so far this boat has gone a best of 70.4 GPS with 5 people and a full tank of gas . And he is still prop testing , 72 is not out of the ball park .
I think it's pretty impressive for small blocks

hell yea that impressive for smallblocks! Throw some blowers and extention boxes on it and....muwahahaha!!!

Some of you must be quoting speedometer speeds, because its very unlikely that this combination would even be in the mid 60 mph.

The P-29 Scarab is an entirely different boat with the black hawks, and probably 5-6 mph faster than an equivelent 29 Scarab with small blocks and bravo's. I believ a stock P-29 only did 75 + or -, a 29 Scarab only higher 60's (maybe) on a good day, therefore the 31 thunder with 350's has to be high 50's low 60's. Audacity probably wasn't that far off with his comment.

My original estimate was based on a couple of things:

1. my 7600lb 28' Cigarette went 67mph w/350Mags/Bravos(on radar).
2. this boat is probably weighing it at around 4500-5000lbs
3. his motors are probably putting out at least 350hp given the mods.

so...my 69mph was pretty close

I have to disagree with your weight estimates. A 33 Scarab (which is a stepped version of the 31) weighs 8400#'s (wow) so I can't imagine a 31 weighs 4500-5000#'s???????? c'mon guys I have a 28 Saber that weighs 6200 dry. And scarab's have always been known to be on the heavy side. I bet it is a lot heavier than 5000#'s

Dan

dunkeneeze..
i fixed i for ya...

I also know that a 89 31 scarab with 454 mags (365's) runs 67-70 mph tops! I have a friend who used to own one. (fresh water) I have never seen a 31 with small blocks that is a very different setup. I was looking for a 31 about 5 years ago

Dan

Lakefront , Buzzinbye
Bring your GPS's ! I don't even look at speedometers !
I think a 31 Scarab with BB's wiegh's #8500 and these SB's are making WAY more than 350hp. 6000rpm's with 21 Mirage plus's do the math.

A 31 with 502 mpi's runs 70.7 .

Trust me I was surprised too.
We all had a speed pool , a bunch of us put in $20 and guessed a speed. I definiltley lost I picked 67.8

"Lakefront , Audacity , Buzzinbye "...how did i get in the middle of this one...i was just making a joke
...i could care less

E Z tiger
I will edit your name out !

I just thought it would be fun to see what people thought, I know I can't believe those little motors can push that tank that fast

I will say that is amazing!! I would have never thought. But what I did know was that a 31 scarab weighs WAY more than 4500-5000#'s

Dan

Okay, I may be a little light on the weight estimates, but Dan, you are comparing a 1989 BB Scarab to 1996 SB model...I would bet my last dollar that the layup schedules and newer technologies have lightened that boat up considerably...also...did the 89 model have TRS or Bravo drives? I also believe that the Saber is build much heavier than the Scarab...

I also said he had to be making at least 350hp...and unless we see dyno numbers, we won't know for sure, but the motor sounds pretty trick to me...

BTW, we did the same thing when we completed my Cigarette...I lost...I said it would do 72mph....

Excellent topic by the way...

I'm glad I did not have any money in that pool . Would have lost big.

Sean,

The weight i was using is from a new 33 scarab with big blocks(8400) which is pretty damn heavy. But most scarabs are. A new 29 scarab with small blocks weighs 5500#'s and is much smaller than a 31. And the 89 was with bravos. My point being is that those must be some kick ass small blocks to push that heavy 31 foot boat 70 plus!

Dan

I haven't looked at any brochures or anything, but I was always under the impression that the newer Scarabs were light boats...not heavy at all...the 30 Scarab Sport comes to mind...a 1997 seemed pretty thin when I banged on the hullsides...I assumed it was light...but...you learn something new every day...

6000 rpms x 21 pitch = 126000
1.5 ratios x 1056 = 1584

126000/1584=79.55 x 10% prop slip = 71.59 mph

The math adds up, those are some strong small blocks!

21x 6000=126000
126000x.667 (1 / 1.5 gear ratio) =84042
84042x.0094697=79.58
79.58x.88 (12%slip)=70.03

Math still works-Pretty impressive

I don't see a few more miles per hour being out of the question w/ better props

Impressive.

ok I am no expert at any of this but I do know the boat your talking about and have been on the water and raced it twice in the patroit. That was early on and he was still putting it all tougher. I believe it ran somewhere short of 70mph. But I think the real thing about the boat is the amount of work the guy has done on it. Everytime I have been to the marina he has been working on it. I give him alot of credit. The boat looks awesome and is a true work of art and a testament to the amount of hard work he has done. Last week I got to go for a ride in the p-29 up to tin fish. That boat is sweet! But like I said I don't know much besides having a good time. Which I think I am an expert at.

Having been in both a P-29 and a 31 Scarab at one time or another, the P-29 is also NARROWER than the 31. Probably about a foot or so. So comparing the two is not really apples to apples. Bravos.....Blackhawks......stock motors.....mod motors.....etc....

Chuck you and that guy coming over for the races??? And I'm still in need of a roomate!!!! Going broke fast!!! You need to bug your company if you want to get into the Customer Center where Rob works. He told me the other day that group is so busy they don't have time for anything but work!!!! Make the call!!!

I do not chalange your word about top speed , but **** thats fast for a Small block powered 31 footer!! especially with 5 people and a full tank of gas!!
There is something your Not telling us. How big is the gas tank. Did you have Five LITTLE people on it. The weight and Drag versus the HP just don't add up. What was the water condition?
Temp. ETC. Carbs, Timming, Blue printed Bottom?
I believe you, but what ever you do for money you should Quit and Build Boats just like yours. Sorry no disrespect ment but the numbers don't add up!!. You have a full cabin or Half Race lay up.
Now I am not even the same BOAT class as Most of you. As My little formula will do at BEST 68.
84, 242 SR1, 5200 lbs, factory hook removed, twin 350s punched 40, 9:1 pistons, Dart 2 heads, Comp 1.6:1 roller rockers, cams, Holly 650, dual feed Double pumpers, Iron High rise Z/28 intakes, worked over ThunderBolt ingnition, Big Coils, Jacobs wires, RV8c champ plugs, Cam 2 gas about 35/40 gallons,
two skinny people, Dialed in all the advance she would safely take., Alpha drives, 1.5:1 , nose cones, worked over 24 Clevers by S&S. Cold air comeing in on both port and starbord sides, 4 3" hot air bildge vents. Stock [NEW} Merc 4" all the way.
Aired the hell out of it, on salt water, with speed bumps. [ nice short close chop].
I must be doing something wrong as mine has to be lighter than yours.
Thanks
NY. Long Island.

I'm impressed i would have thought mid 60's tops.

hey Sean you are right about the scarab line, it has lost some weight just check out some of those AVS hulls!!they are running some great speeds with stock power