44446A2 Aftermarket Mercruiser 7.4L Big Block Rear-Mount Heat Exchanger | Sawley's Select Marine Parts

🔧 Product Description

Aftermarket replacement Rear-Mount Engine Heat Exchanger - Replaces Part Number: 44446A2

New copper-nickel rear-mounted heat exchanger replacing MerCruiser 44446A2. The approximately 5-inch exchanger mounts over/behind the transmission on closed-cooled GM 454 CID 7.4L inboard packages.

⚙️ Key Features

• Direct replacement for MerCruiser 44446A2

• Approximately 5-inch diameter rear-mount configuration

• Designed for GM 454 CID / 7.4L big-block engines

• Copper-nickel seawater tube bundle

• Original-style transmission-area mounting geometry

🧰 Kit / Assembly Contents

• 1 × Complete rear-mount heat exchanger assembly - P/N 44446A2

• 1 × integrated copper-nickel tube bundle

• End-cap seals, zincs, hoses, brackets and mounting hardware are renewed separately unless included

🔄 Supersession & Cross Reference

OEM Supersession Chain:

• 44446A2 (MerCruiser reservoir/heat-exchanger assembly reference)

OEM / Related Numbers:

• 44446

• 44446A2CN

Aftermarket / Verified Equivalents:

• Seakamp: 44446/44446A2 copper-nickel exchanger

• Lenco: LE44446

• Mr Cool: MRC44446A2CN

🚤 Compatibility

Commonly used on:

• MerCruiser closed-cooled GM big-block inboard engines

Typically suits:

• Engine / Equipment models:

• 7.4L MIE GM 454 V8, including 1988-1992 serial range 0B788366 through 0D715493

• Other rear-mount 454 CID inboard packages whose parts catalogue specifies 44446A2

• Output / Engine Rating: Approximately 330HP - 365HP, calibration-dependent

• Engine / System Type: GM 454 CID / 7.4L carburetted or fuel-injected V8 marine engine

• Year Range: Principal documented application approximately 1988 - 1992

• Serial / Model Identification: Confirm rear-mount configuration; this exchanger is not the front-mounted 7.4L style.

🔌 Function

The heat exchanger transfers engine or generator coolant heat into the raw-water circuit while keeping the two fluids separated. This maintains the correct closed-circuit operating temperature and protects the engine from direct seawater circulation.

Common signs of failure:

• Engine or generator overheating under sustained load

• Coolant loss without an obvious external hose leak

• Saltwater and coolant cross-contamination

• Restricted raw-water discharge or uneven end-cap temperature

• Corrosion, green staining, cracked solder joints or pressure-test failure

📦 Condition

• New aftermarket replacement part

• Brand new

• Supplied in original or equivalent packaging