Marine Exhaust Manifold 18-1953-2 87114 860246 For MCM/MIE GM V8 (305, 377 CID)

Marine Exhaust Manifold for MCM/MIE GM

This marine exhaust manifold, cross-referencing part numbers 18-1953-2, 87114, and 860246, directs exhaust gases out of compatible V8 marine engines while maintaining proper water cooling.

Overview

This marine exhaust manifold is designed to withstand the harsh operating environment of saltwater and freshwater boating. Featuring thick cast construction, this marine exhaust manifold provides uniform wall thickness to prevent premature burn-through and internal water leaks into the cylinders. This marine exhaust manifold is an essential replacement component to maintain safe engine operating temperatures and reliable exhaust flow.

Built For Performance

• Heavy-duty cast iron construction to resist corrosion and thermal expansion.
• Precision-machined mounting surfaces for a leak-free seal against the cylinder head.
• Optimized water passages to ensure consistent cooling jacket flow.
• Internal corrosion-resistant coating to extend lifespan in marine environments.

Fits These Machines

• for MCM/MIE GM V8 (305 CID) engines
• for MCM/MIE GM V8 (377 CID) engines

On-The-Job Use

• Replacing cracked or rusted-through exhaust manifolds to prevent engine hydrolock.
• Restoring correct cooling water routing within the boat exhaust system.
• Refurbishing marine inboard and stern drive engines during winterization or spring prep.

Specs At A Glance

Good To Know

Q: Why do marine exhaust manifolds need to be replaced periodically? A: Because they channel both hot exhaust and raw cooling water, the inner walls eventually corrode and thin out. If left unchanged, water can leak back into the cylinders and destroy the engine via hydrolock.

Q: Does this manifold come with the mounting gaskets and bolts? A: This manifold is sold as the main cast unit. It is highly recommended to purchase new marine-grade mounting gaskets and high-strength fasteners separately to ensure a proper gas and water seal.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.