BluePrint MBP3830CT Marine GM 383 Stroker 405 HP Base LB Long Block Crate Engine

Description

Eliminate severe marine watercraft downtime using the BluePrint MBP3830CT Marine Crate Engine. Displacing 383 cubic inches, this marine stroker long block outputs 405 horsepower at 5400 RPM and 440 lb-ft torque at 4200 RPM. High nickel block metallurgy, marine valves, and brass core plugs furnish enduring reliability for heavy offshore cruisers and commercial workboats.

A heavy cast iron four bolt main block provides torsional strength under severe water load resistance. The stroker kit contains a 4340 forged steel 3.800 inch stroke crankshaft, forged 5.700 inch connecting rods, and forged aluminum pistons inside 4.000 inch bores. Static compression measures 9.5:1 for 89 octane marine gasoline. An eight quart baffled marine oil pan sets bare dry weight at 460 lbs.

Key Features of BluePrint MBP3830CT

Buy BluePrint MBP3830CT crate engine units to repower twin engine cruisers, offshore runabouts, and towboats with big block torque in a small block package. The long block format allows marine mechanics to reuse existing marine induction, cooling manifolds, and ignition components.

• Corrosion resistant brass freeze plugs protect the engine block against brackish and raw salt water.
• Heavy duty cast iron cylinder heads resist thermal warping and deliver dependable long term valve seat seals.
• Stroker 3.800 inch forged crankshaft produces 440 lb-ft torque to pop heavy boat hulls onto plane fast.
• Marine profile hydraulic roller camshaft maintains valvetrain stability throughout long wide open throttle runs.
• BluePrint MBP3830CT valvetrain parts feature hardened pushrods and heavy duty valve springs for marine RPM.
• Four bolt main bearing caps provide bottom end strength for demanding hauling and towing tasks.
• Baffled marine oil pan holds eight quarts to ensure positive oil pump suction during aggressive hull pitch changes.

Marine Stroker Powerband Verification Measurements

Dyno testing validates 405 brake horsepower at 5400 RPM and 440 lb-ft torque at 4200 RPM across an effective 2000 to 5500 RPM operating spectrum. The roller cam features 224 degrees intake and 230 degrees exhaust duration at 0.050 inch lift, producing 0.528 inch intake and 0.536 inch exhaust lift. The motor pulls 14 in-Hg vacuum at 850 RPM on 89 octane fuel, holding 50 to 65 PSI hot pressure.

Marine Transom Stringer Fitment Clearance

Standard small block Chevrolet dimensions drop straight into factory marine engine beds and stringer motor mounts. The crankshaft requires an external 400 balance marine flywheel or drive coupler matched to MerCruiser Bravo, Alpha, or inboard transmissions. Exhaust ports align with standard marine exhaust manifolds, while the deep marine pan clears hull bottom V-sections.

Watercraft Pre Lube Service Regimen

Technicians must pre prime the oil galleries using high zinc marine break in oil before initial start. This marine crate engine is not engineered for automotive road racing applications, forced induction boost exceeding six PSI on standard ring gaps, or unmetered nitrous systems.

• Drain break in lubricants and replace the spin on filter after the first 25 engine operating hours.
• Change crankcase motor oil every 50 operating hours or every 12 months with high zinc marine oil.
• Inspect cooling water circulating pumps and examine spark plug coloration every 100 boat operating hours.

Marine Factory Warranty Physical Inventory

Protection includes a 24-Month / Unlimited-Hour marine factory limited warranty guarding against defective components. The shipment crate contains the assembled long block, cast iron cylinder heads, stamped valve covers, timing cover, marine oil pan, harmonic balancer, comprehensive installation guide, and an official dynamometer run sheet.