[dwightprophet]

Hi Everyone
Im New to this site and would like some input from anyone on motors. I have a 1999 250 shabah with a 7.4 motor that is blown i would like to put in a 502 cu in rated at 700 - 800 hp can this boat handle this motor iit would also be carbarated instead of fuel injected. Any help would be great.
Thanks
Dwight

[ColoradoDiablo]

Your stock Bravo drive is gonna gernade in short time. If you install XR internals it'll last for awhile , but that kinda ponies.....you need a good XR drive period. Along with hydraulic steering ,some good trim tabs , and I'm sure lots more.

JMO

It would be a helluva a ride though

BTW: Welcome to MOC!!

[dwightprophet]

Oh Well that sounds like to much dollars ill hato think it over, and yes it would be a good ride, thanks for your input
Dwight

[Oregondunes]

the B3 drive unit is good for about 500hp and not much more (even with XR guts).

can you tone down the motor your thinking of ?

in the next 60 days Ill be yanking the stock 7.4 from my boat (400 hrs). It runs perfect and Ill have leak down and compression numbers just prior to removal if your interested in a replacement.

[dwightprophet]

thanks for the info how much would you be asking for your stock motor and why are you replacing
Dwight

[ShabahZ280]

The Z250 isn't structurally built to handle that much HP. The largest I've ever seen in that boat is a stock 502. I wouldn't go anywhere over 425hp in that boat without some significant structural improvements which would require much more work than you'd ever want to do.

These boats are NOT meant to be speed demons. If you want a boat to support 700-800hp, buy a Cigarette, Donzi, Baja, or Fountain. They've got a stronger stringer system and a hull that's meant to handle the massive amounts of stress that much HP would put out.

[Oregondunes]

Originally Posted by dwightprophet

thanks for the info how much would you be asking for your stock motor and why are you replacing
Dwight

I too am seeking more speed (= more power). I got a lil year end bonus of sorts and would like to be able to atleast beat the wake board boats in our group (55+ mph).

Im either going to build a 502, 509 or 540ci motor. My 454 motor is perfect. runs and starts everyday and a marinized BBC has some value especially after the winter months when people learn exactly how cold it really got.

Ive got a lot of the parts already (roller cam, lifters, rockets, girdles, exhaust, heads, block). Just need to decide on bore and stroke next and start the machining process.

Ive steeped up to 28p props and am looking for 450-500hp and a max RPM of 5500. Id like to be able to run comfortably at around 5200, so Im going to build a motor that can handle 6000rpm and a 3-5 lb blower (if necessary).