SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: turbo350r on November 13, 2008, 07:39:52 PM

Title: WHAT DO YOU THINK?
Post by: turbo350r on November 13, 2008, 07:39:52 PM

454 Chevy   

Stock GM Cast Crank   VS   New Scat Forged       :sly:

Title: Re: WHAT DO YOU THINK?
Post by: beerjet on November 13, 2008, 07:47:49 PM

Lets get into some specifics here .

1. Whats it going in ?
2. Pump gas motor or high compression motor ?
3. What about the rest of your combo , Cylinder heads , intake , cam, ect, ect.
4. Ultimatley , what are you trying to acheive , Cruiser or a racer . You cant have both . :sly:

-beerjet-

Title: Re: WHAT DO YOU THINK?
Post by: turbo350r on November 13, 2008, 08:13:05 PM

1977 SPECTRA 24 XS
 
TURBO 400 V-DRIVE

PUMP GAS

98CC CLOSED CHAMBER HEADS, FULL ROLLER, AIR GAP MANIFOLD, EXTREME MARINE COMP CAM

CRUISER WITH BALLS,  TOWING SKIERS

GOT MY EYE ON A 489 STROKER :sly:

Title: Re: WHAT DO YOU THINK?
Post by: beerjet on November 13, 2008, 09:24:29 PM

XMH 278 cam I assume  ;D

-beerjet-

Title: Re: WHAT DO YOU THINK?
Post by: enginedoctor on November 14, 2008, 03:00:34 PM

I agree w/BEERJET!  All depends on what you plan to achieve.

Decide what you wan't, then you can move on with the correct engine parts combo. :)

Title: Re: WHAT DO YOU THINK?
Post by: beerjet on November 14, 2008, 04:16:55 PM

I realize forged is the way to go . But it is more money . He has a freshly turned crank and rods std/std . He also has a fresh set of closed chamber , large oval port heads and a roller cam as I mentioned above . The way I see it , he should run the fresh cast crank and stock rods with some good bolt . Reassemble and enjoy . I dont see those heads and cam really pushing a stock rotating assembly beyond it's limits . Save the coin and put it in your tanks . Thats my (https://forum.socaljetboats.com/proxy.php?request=http%3A%2F%2Fwww.socaljetboats.com%2Fcpg%2Falbums%2Fuserpics%2F10034%2Ftwocents.gif&hash=b6c1002b10468156bb81930782cd2eec47436037)

Believe me , forged is the way but with the turbo 400 trans , I dont think you need it . Put the money in some good pistons and someone to put it together for you correctly .

-beerjet-

Title: Re: WHAT DO YOU THINK?
Post by: GlassCutter on November 14, 2008, 05:10:31 PM

I think conventional wisdom says that a stock crank is actually OK until you start approaching 700 ponies.  You should be very safe with a stock (magnafluxed of course) crank AND $$$ ahead.

Title: Re: WHAT DO YOU THINK?
Post by: jet boat performance on November 15, 2008, 07:30:14 PM

are you going to balance the motor ? if your going back stock with stock weight pistons and rods etc go with the cast crank if not , Got a couple of BBC steel cranks on the shelf if ya need one  Tom

Title: Re: WHAT DO YOU THINK?
Post by: enginedoctor on November 17, 2008, 04:55:49 PM

Regardless of your combination,   You should balance your rotating/reciprocating weights.
Just my thoughts. :)

Title: Re: WHAT DO YOU THINK?
Post by: jet boat performance on November 17, 2008, 07:27:40 PM

Quote from: enginedoctor on November 17, 2008, 04:55:49 PM

Regardless of your combination,   You should balance your rotating/reciprocating weights.
Just my thoughts. :)

Cant disagree Doc ,but a balance isn't always in evreyones "grasp"  Tom