SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: Sicaz66 on April 28, 2013, 02:06:07 PM

Title: 496 in a 21' open bow
Post by: Sicaz66 on April 28, 2013, 02:06:07 PM: Just picked up a 496 short block for a killer price. Has 4 bolt block,scat forged steel crank,h- beam rods,probe forged pistons. Seems like a good builder with new bearings and fresh rings.just looking for heads. May just have my 049's done. Any one got an idea of what to expect in 21' bahner open bow?
Title: Re: 496 in a 21' open bow
Post by: mash on it on April 28, 2013, 02:11:06 PM: 454, daycruiser, spinning a 'AA' American turbine impeller @ 4800 56-58, depending on air/water conditions

Dan'l
Title: Re: 496 in a 21' open bow
Post by: JMS-1 on April 28, 2013, 03:33:34 PM: Was that the one on craigslist ? If it is, Nice score. What size domes are on the pistons? I would find out before making any decesions on heads yet.
Title: Re: 496 in a 21' open bow
Post by: BIG JOHNSON on April 28, 2013, 03:51:11 PM: My 21 will do 58 on gps with a mild 454
Title: Re: 496 in a 21' open bow
Post by: Sicaz66 on April 28, 2013, 04:14:19 PM: Quote from: JMS-1 on April 28, 2013, 03:33:34 PM
Was that the one on craigslist ? If it is, Nice score. What size domes are on the pistons? I would find out before making any decesions on heads yet.
Yes it is. They are flat tops.it had cast rectangle ports.Found out my friend bought a boat that was a theft recovery( they stole the top end off the motor)and traded this guy the short block and cash for a fresh 502. Luckily he still had all the paper work on the short block.gs marine built it back in 2009. Guy spent $13000 on it with a fresh pump. Looks super clean inside. But has been sitting so will need to come apart for a refresh and gaskets. Got it for almost half what guy was originally asking. Going full roller with some good heads,rpm airgap intake,and an 850dp,will get lightning headers down the road. Hoping to make a solid 600hp.going to bostick when my pump is done. ;D
Title: Re: 496 in a 21' open bow
Post by: sevans01 on April 30, 2013, 09:46:18 PM: Quote from: BIG JOHNSON on April 28, 2013, 03:51:11 PM
My 21 will do 58 on gps with a mild 454

Whats mild about it? I would eventually like to get there. Just need to know what direction to go.
Title: Re: 496 in a 21' open bow
Post by: BIG JOHNSON on May 01, 2013, 03:58:36 AM: Quote from: sevans01 on April 30, 2013, 09:46:18 PM
Whats mild about it? I would eventually like to get there. Just need to know what direction to go.

It's a stock 1994 Marine power 454 with 610hrs rated at 390hp with square port heads and not many hours since McClure rebuilt the pump.
Title: Re: 496 in a 21' open bow
Post by: sevans01 on May 01, 2013, 12:31:30 PM: Thanks! I gotta see if the time and money is even worth an extra 60 hp.
Title: Re: 496 in a 21' open bow
Post by: Sicaz66 on May 01, 2013, 09:45:40 PM: Taking it over to Bostick in the next few weeks.He's Talking 600-650hp >:D