Hull Power Limits
 

Question: I am re-rigging and re-powering a Scarab 22 (please don´t ask "why") and in my country it is necessary to get all major changes certified, like a new engine. Authorities demand a note from the manufacturer that the hull is capable of handling the power without disintegrating.
My boat will get a 377 Scorpion with a Whipplecharger kit. I do not know how much horses this will make, but certainly more than the old carbureted and normally aspirated 350 Mag/Alpha.

I contacted Wellcraft (phone, they wouldn´t answer my e-mails) and they said that the max power this boat was fitted with was a 7.4 MPI (330 hp I think), so they can´t say nothing to my setup except it hasn´t been done from the factory (is that so...) and so no comment (but no "don´t" either).

And here finally my question: I think I read somewhere that USCG regulations demand any boat above a certain length to have no power rating or limit (the hull, that is), or they say it don´t need a power rating or limitation.

I can´t remember exactly what the text said if it indeed exists.
If it does (or something similar), can anyone tell me where I could find it. I tried to research on the net but no luck.

Thanks

Peter

Re: Hull Power Limits
 

What is the power rating of the scorp? 350hp? If so, then I'd use the mfr's max power that they have installed (330hp). Add the blower later after all the inspections have been done. If they gripe about the 20 or so hp difference, show them the difference in torque. I know that the scorp makes the same if not less torque than the big block.

Re: Hull Power Limits
 

Swap it with a modified 4.3 Syclone V6 engine and name it "Cigarette Smoker"
PLEASE LET ME BUILD IT! :D:D:D :D

I want to repower mine with a 500EFI and have no problem doing so. I have found a site that has good Wellcraft info. Let me find it and I will post it shortly.

Roby

Re: Hull Power Limits
 

Here you is:

http://www.wellcraft.com/Resources/R....asp?mdyr=1998

Roby

Re: Hull Power Limits
 

Peter,
Typically the max HP ratings/plates placed on boats for the USCG crap is just for boats with Outboards; i.e. Bass fishing boats, and pontoons, and the like. I do not think you will find a rating other than what the factory gave you, for their max HP factory installed engine package.

Re: Hull Power Limits
 

Hunt down Larry Smith (The designer) and get something from him saying what it is rated at.

Re: Hull Power Limits
 

Do boats still come with that metal plate that states the maximum horse power and maximum weight??

Re: Hull Power Limits
 

thanks guys

my decision is now made: i´ll fake some ominous paper stating there´s no limit for the hull. what the heck.

and roby: when the boat is finished, there will be a modded syty engine (got to save a little money first...).

again, thanks everyone!

peter

Re: Hull Power Limits
 

The rating is based of the size of the boat. I can't recall the cut off right now, but you are over it, thus there is no capacity plate. That said, if you fake the document, you'd better hope that they don't check it.

Re: Hull Power Limits
 

anyone thinking safety here?

Re: Hull Power Limits
 

yea we just got done reriging a 96 22 with 550 hp 502 280 k planes and full hyd steering runs straight with slight chine walk. so far 78 on gps. no problems you may not have to use this large of k planes but you should look into FULL hyd steering good luck james.

Re: Hull Power Limits
 

If your transom goes underwater when you splash the boat, you've got too much power.

Re: Hull Power Limits
 

Rj please tell me your joking.????

Re: Hull Power Limits
 

A fellow local boater has a 22 scarab w/built n/a smallblock,he claimed 67.8 mph w/23 pitch 3 blade,he is currently installing 540 n/a f.i motor,expects low to mid 80's,IF he ever gets it running i'll post results,he's going to start out w/26 pitch 4 blade i sold him.

Re: Hull Power Limits
 

A good friend and I were going to do this with an 18' Celebrity. It was all black and would have looked cool. We were looking into building a 700-HP Sy/Ty engine but ran out of funds. Besides the stock Alpha would have never stood for it. Eventually we built the engine and it Dynoed 738 HP at a lowly 5600-RPM W/632 ft/lb torque at a very lowley 3250-RPMs on only 23.5-PSI boost. And get this!! It was without an Intercooler because the neck cracked and it wouldn't hold water. We went all out on this engine. I built my own fuel rails because good ones for the 6 just didn't exist. I still wanted to do the project but he got married and I was in the process of trying to get married. We sold the engine for a pretty penny. Wish I could do it again.

Roby

Re: Hull Power Limits
 

I think there´s a little more to say:

first, i don´t think i am going unsafe here.

i remember george or whatever his name was with his 18´ donzi with 700hp BB and an arneson surface drive that was capable of 100+ mph and he had to mess with his transom before to fit the arneson (you can find the link to his story somewhere on the arneson website), no one talking safety there.

our scarab hull here has been ripped apart, new floor, new reinforcements, glass gussets and reinforcements wherever it seemed necessary, all major cavities have been filled with polyurethane foam for additional strength. the boat will be run on a river only, no real offshore conditions and will be far away from going 100 anyway.

about the faking of the hull information: pretty much all of the guys in this forum wouldn´t hesitate to re-power their boats, and many do or add a blower which already means a major change in power and you don´t need to do any certifying or have some idiot who doesn´t even have a boat tell you what to do.

the papers i need are for certification only, NOBODY is really interested in what i do. we get directions and limitations what the boat has to carry in safety equipment (or what the authorities think that is) but NOBODY checks for the integrity of the hull, cracks, engine mounts, leaks or whatever. but we need to have a rudder position indicator on the steering wheel or an electrical one, just to show you how serious all this BS is.

this boat has a placard that allows it to carry 8 people-now that is a safety issue, even with the stock engine. i have no idea how you could stuff 8 people in it and still drive it comfortably. we will have the capacity reduced voluntarily to 5 people max.

about the weight: the stock 7.4 MPI it was available with from the factory was presumably heavier than our 377 will be.

scarabj: the boat gets an IMCO extension box, full hyd steering with 2 rams and EddieMarine tabs (the larger ones), bravo xr sportmaster drive. and pretty much everything is different from the stock boat (racing seats, custom upholstery, new dash completely changed with glass, new gauges, remote start, bla bla), i´ll post pics when its finished.

just to show you this isn´t kids play and there are people behind this who know what they are doing. we are doing this as a company, for money. last year we put a 496HO into a 206 Formula (something Formula said cannot be done). Formula gave us a paper saying that their hulls do not have any power limits at all, i thought Wellcraft was probably willing to do the same but no luck. strength shouldn´t be an issue, the scarab´s transom is even a few millimeters thicker than the formula´s.

again, thanks.

roby, too bad you sold that engine. i will start carrying parts for the sy together when the boat is finished. right now we are building an engine for a customer (eagle rods, ATR headers, Aquamist Water Injection etc.), i am curious how it will do and then i´ll go shopping...

peter