Leprican28

I recently got a 1990 Baja 250. The dealer said it had some engine work done and they claimed it has 415 HP. Well, I got it as a project so i pulled the motor to check internals and because I dont want to get stranded b/c of someones crappy work. It has a 454 2 bolt main block # 14015445. It has been bored .030 over with flat top pistons. Stock rods and crank. Stock intake, carb, manifolds, non roller. The head #'s are 3933148. My question is what can I do to this motor to get max HP using these heads and Stainless Marine Exhaust. Oh and it has Thunderbolt IV ignition.

Intake?
Carb?
Cam?

picklenjim

Those are large oval 396 heads which is a good start point as they provide a little extra compression. Put the larger valves in if they haven't been yet. 2.19" intakes and 1.880" Inconel exhaust. Little chamber work to unshroud the valves. RPM Air Gap dual plane intake. 750 Holley DP marine carb. Mild hydraulic roller cam. Roller rockers. Your ignition should be fine. Don't try to go any crazier with the cast bottom end unless you want change it all also. Bottom line depends on how much you want to spend. This alone is going to put ya back 2 1/2 to 3K.

Or kick in another 2K and get one of these. Much better in the long run.
http://www.offshoreonly.com/forums/s...easonable.html

Leprican28

Just pulled the cam. Its got a Comp Cam 11-556-4 already in it. That any good?

Leprican28

Picklenjim what kind of HP would I be looking at with that setup?

picklenjim

That cam is comparable to what merc had in a 370. I would think that would be closer to what that motor had, about 370 hp. The parts I mentioned I would quess would make 425+ hp. Personally I would have used a cam with a little more lift. Here's that cam.
http://www.summitracing.com/parts/CCA-11-556-4/
Now if you stayed with a flat tappet hydraulic cam that would save you probably $7-800 over a roller. All depends on your budget.

f_inscreenname

This is my non roller motor before,
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.

Then I went roller and a 4 bolt Mark IV block,
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 - 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

bcfountain

what was the diffrence in speed and h/p between the two motors?