Reinforced cylinder head gasket Ferrari V12 F133 550 575 612

The Ferrari engines covered

The F133A, F133C, F133E, F133F and F133G engines are the V12 engines of 5.5 and 5.7 litres, with 48 valves, fitted to the Ferrari 550 Maranello, 550 Barchetta, 575 M Maranello, 612 Scaglietti and 575 Superamerica, detailed in the table below. The gasket is sold individually and the engine needs two, one per cylinder bank.

The original part numbers on record are 142865, which replaces 153509, for the F133A and F133C, and 204528, which replaces 185558, for the F133E, F133F and F133G. The manufacturer publishes neither the bore, nor the construction, nor the thickness.

Reinforced cylinder head gaskets

A head gasket does not seal alone: the studs or bolts clamping the head to the block do half the work. Composite gaskets give up for good beyond 100 N/mm², whereas the 301 stainless steel of an MLS holds 517 N/mm² and springs back after every combustion. Follow the workshop manual when replacing the fasteners.

This page presents one part number from Athena, an Italian maker of racing gaskets, in a single construction: MLS, a multilayer stainless steel. Its bore is 90.5 mm and its thickness 1.50 mm. It is sold individually: allow two gaskets for the V12, one per cylinder bank.

Technical specifications

A gasket's volume is the space it leaves free above each cylinder. That space joins the combustion chamber and lowers the compression ratio; only gaskets of the same bore can be compared. Here, the bore offered is 90.5 mm.

Preparation and fitting

Before fitting, run a straightedge over the head and block faces to check flatness and have them skimmed if needed. Athena supplies the gasket ready to fit: apply no sealing paste, and repeat this check at every rebuild of an older block.

Technical guide

The construction offered

Athena MLS Several layers of AISI 301 stainless steel, laser cut, stamped and then riveted together. Around each cylinder, a layer folded over on itself, the Gas Stopper, concentrates the clamping load on the combustion chamber, while beads block the water and oil passages. The outer layers carry a two-coat finish: the first withstands high temperatures and fills small irregularities of the block and head, the second, silicone based, keeps the gasket from sticking at removal. It is Athena's all-steel answer, from the tuned naturally aspirated engine to moderate forced induction. Here, the MLS is offered in 90.5 mm and 1.50 mm.

Choosing bore and thickness

Gasket bore. The Athena MLS comes in 90.5 mm (338404R), with no other bore.

Thickness. The manufacturer gives no thickness for the original gasket: only the figure measured on the removed gasket applies. A thicker gasket enlarges the combustion chamber and lowers the compression ratio; a thinner one reduces it and raises the ratio.

With no known original thickness, use a dial gauge to read how far the pistons rise above the block face, especially if the removed gasket is thicker than 1.50 mm: that figure gives the clearance left between piston and head. On these engines, the measurement is made with a dial gauge, head removed.

The brand

Athena S.p.A. is an Italian maker of gaskets and engine components, established in Alonte, in Veneto, where its head office and main plant stand. It also has sites in Spain, the United States, Brazil and India. Several carmakers fit its multilayer gaskets on the assembly line, and its entire racing range is designed and built in Italy. Part number 338404R is the one on this page.

Advantages over the original gasket

When a reinforced gasket becomes necessary

• Adding forced induction, or raising boost on an already turbocharged engine
• Cylinder rebored beyond what the 90.5 mm bore of the gasket offered covers
• Looking for a compression ratio different from standard, higher or lower
• Engine that has already lost its gasket, or is consuming coolant
• Competition use, where the gasket goes through repeated temperature rises

Vehicle compatibility

OEM part number: 142865 for the F133A and F133C, 204528 for the F133E, F133F and F133G.

Important: the part number on this page suits the F133A, F133C, F133E, F133F and F133G engines: check the engine code of your Ferrari before ordering.

Why switch to a reinforced gasket?

When the original gasket is no longer enough, the reinforced gasket takes over: under higher combustion pressure it keeps its shape instead of being crushed. These Ferrari V12 engines find here a gasket with an 90.5 mm bore.

Turbo, supercharger or a raised compression ratio: the head gasket is the first part stressed, the weak point of the top end. A reinforced gasket prevents the leak, and the head removal that goes with it costs well above the gasket. This holds for these Ferrari V12 engines as for any hard-driven engine.