this past winter i had the 7.4 mpi in my 22zx rebuilt,and now i have the not fast enough sickness.the motor was built stock except for JE forged pistons the only part not new is the fuel pump rods and crank.literally any other part that touches this moter is new.i have spent months searching forums and have found good info.i am fully aware that this engine has a cast crank.but im dead set on saving the bottum end but what is the recipe to make this 454 all it can be.i want real hp.ive studied the 330 on roids but to my knowledge the could be things done different with better results. what heads,cam, carb,and ignitoin will give me maximum results possible while staying naturally aspirated.

The lower end is the limiting factor, and the heads. Here is what I'd do...

1) exhaust, stainless marine or similar
2) heads/intake/carb -- large oval port heads (aluminum if not in salt) and matching edelbrock rpm intake and carb
3) cam - get a custom grind with lots of lift and mild duration to keep rpm's down below 4800 (4600 preferred) Marine Kinetics would be a good start here.
4) realize that's way to much money to invest in a 454/330 and at the end of the day you'll probably only get 4-5 mph and just buy a complete set-up that's done and keep the stock motor as a spare or sell it complete.
OR
Just enjoy it and maybe step up 1" in pitch on you prop and have the prop lab finished and gain 1-2 mph and be happy with the reliable package you have. That being said a nice set of exhaust manifolds would fit nicely and could be used on another motor as well. As noted above Marine Kinetics is a reputable place if you are serious about doing it and can help guide you putting together a nice package...but you can likely find a mag motor or even a 502 for not much more than the cost above. If you are a smart shopper you can do this in stages and pick things up as you find good deals.

Hey just did this with my 97 22zx but started w/ 454 Mag with Carb.
Did a complete with forged bottom end 496 stroker. I did call Bob at Marine Knectics. Bob will help alot and will cut whatever your need for your app. I found GM Cast # 781 heads on Craigslist. Just so happened that they had been ported etc for a roller application fanastic flow numbers and only $850 vs thousands. got luck shop that did work is well known for work by many in this area(great Rep).
Bob and shop (Kim Barr Racing Engines)that bore and installed lower said engine would be very strong, crazy strong it is I have about 11 hrs on so far so just done. have just been running max 3000-3400 rpm first oil change yesterday after running. Stainless Marine exhaust with HP 500 high risers because of cam and possibly reversion but wet exhaust.

3200 rpm 52.8 mph gps 28 P bravo 1

Gets on plane very well going to try 26P prop but think will be to much maybe just use to pull tube and wife/and her friend on skies but since they weight about 116 to 121may not be neccessary

Oh and added ProCharger 3.5 lbs but haven't even gotten into boost yet.

My other boat was a classic 18 which was a awesome handling boat ran like on railroad tracks just awesome, 22zx appears it will be just like it now, Very Happy

PS Before work, I was at WOT 5000 rpm 62 GPS with Mirage Plus 21 P


this setup without PC boost should be about 75+, punched it last weekend to about 4200 rpm and had a topspeed on gps of 72.8 Vac/Boost gauges never moved -into boost stay in Vac at about -2 to -4

http://www.offshoreonly.com/forums/g...4l-hop-up.html
is a nice old read...

I should put this answer on speed dial.
Here is what I did on the last couple motors that turned out pretty nice.

1986, MIE/340 (7.4) 454 Big Block
Dip it and hone the decks and cylinders (the cylinders did not need to be cut and are standard bore)
Block was detailed with all casting debris removed
Stock seasoned crank (also cleaned up)
Reconditioned connecting rods
ARP Rod bolts
.210 Domed Speed pro pistons and pins. (They should give me 9.38 to 1)
Molly piston rings
Federal Mogal bearings (cam, main & rod)
Cloyes true double roller timing chain
Moroso Chevrolet 454 Stud Girdles #6729 BBC
Crane #132561 hydraulic cam--Duration Advertised: 298° Intake / 306° Exhaust Duration @ .050'' Lift: 228° Intake / 236° Exhaust Valve Lift w/1.7 Rockers: .530'' Intake / .551'' Exhaust Lobe Separation Angle: 114°
Crane #99277 lifters
Comp Cams High-Tech pushrods #7954
Completely refreshed Chevy 14096188 heads / 454 Open / 118cc / 3angle valve
Comp Performance Valve Springs #911-16
Pioneer head bolt sets
ARP 1.90 rocker studs
Norris S/S 1.7 roller rockers
Melling H/V oil pump
Melling HV oil pump shaft
EDELBROCK BBC R2 AIRGAP INTAKE
JEGS 15951 - Mechanical Fuel Pump
Pro Comp Ignition
Pro Comp distributor
Super Stock coil
8mm Accel Hi performance wires
New single wire alternator
Mini (gear reduction and fully marine) starter
Edelbrock 800 carburetor
12" aluminum, oval air cleaner (with K&N filter)
Brass freeze plugs
Stainless steel bolt set
4” Stainless steel risers
GLM aluminum exhaust manifolds
Sherwood motor mounted raw water pump.

If you want to do a stroker...

1987, MIE/340 (7.4) 454 4 bolt main Big Block
Dip it and hone the decks and cylinders cut .060 over
Block was detailed with all casting debris removed
Scat 9000 Crank 4.25, 496 stroker
Scat 26385P - 6.385 in. Connecting Rods - Bushed -I Beam Forged 4340 steel
Howards Cams 120255 - Max Torque Retrofit Hydraulic Roller Camshafts, Hydraulic Roller Tappet, Advertised Duration 288/294, Lift .585/.610, 112 L/S
Howards Matching Valve Springs 98636 - 130# / 330#
Cloyes Gear 9-203 - Cloyes Wear Plate, 031 in. Thick,
Maxspeeding Hydraulic Retrofit Roller Lifters
Probe 496 Dome Top +18.0cc - SRS Piston Set
Clevite 77 Cam Bearings
Federal-Mogal 4400 M20 Main Bearings
King Engine Rod Bearings CR849HP
Cloyes true double roller timing chain
Mahle - Plasma Moly Coated piston rings
Melling 10778C (Anti-Cavitation) oil pump
Melling HV oil pump shaft.
New Harmonic Balancer
Rotating Assembly Fully Balanced
Comp Cams High-Tech pushrods #7954
Completely refreshed Chevy Heads 14096188 / 454 Open / 118cc / 3angle valve
APR head bolt sets
ARP 1.90 rocker studs
Norris S/S 1.7 roller rockers
Seal Power Gasket set
EDELBROCK BBC R2 AIRGAP INTAKE
Pro Comp 2752 Fuel Pump
Pro Comp Ignition
Pro Comp distributor
Super Stock coil
8mm Accel Hi performance wires
New single wire alternator
Mini (gear reduction and fully marine) starter
Edelbrock 800 carburetor
12" aluminum, oval air cleaner (with K&N filter)
Brass freeze plugs
Stainless steel bolt set
4” Stainless steel risers
496 MerCruiser exhaust manifolds with Tall Risers
Sherwood motor mounted raw water pump

I thought of you when I saw this. These are cheap and easy, will save you a TON of weight and get decent power improvement over the stock ones, and for $300's, that's a steal...


http://www.speedwake.com/forums/showthread.php?t=73282

thankx for the reply's.(f inscreenname) what would you rate the hp at on those builds?(egbolt) that zx sounds sick,my goal would be around 75mph.i.By the way mother f$ck efi/mpi set up,i cant wait to get that **** out off my boat its been nothing but a pain in my wallet.im just throwing around numbers but wouldnt it around 450 to 500hp for me to get to 75mph.idk wether to replace my crank and rods with forged parts then slap on a super charger or just build a buy another block and stroke it!but i do know i cant afford to stroke and supercharge charge.it would have to be one or the other. i already have way to much money in this boat for what it is.

Nothing like the whine of a blower...

1st = 420+hp
2nd = close to 500

Thanks for all the help!what kind of money should I be able to get for my mpi system with heads and everything included