When is it necessary to replace a valve head?

When is it necessary to replace a valve head?

The spring retainers, keepers and other hardware is likewise inspected. Any worn or damaged components are replaced. New valve guide seals are always used. The valves are then installed in the head and shimmed to restore proper valve height. This is necessary because machining the valves and seat alters their dimensions.

What was the difference in cylinder heads in 1959?

The top two bolt holes were closer together than the lower bolt holes. Valve covers were made with bolt holes to match. In 1959, the valve cover holes in the heads were changed so that the holes were the same distance from one another across the top when compared to the lower holes.

What’s the difference between 2V and 4V cylinder heads?

Port and valve size is the same as a 2V/4V head with 1.78/1.45-inch valves and 1.94 x 1.04-inch intake and 1.24 x 1.00-inch exhaust ports. Where the Hi-Po head differs is valvespring pockets and screw-in rocker-arm studs for better stability at high RPM. These heads are easily identified by the “289” with two dots along with the numbers “19,” “20]

What’s the difference between vortec heads and regular heads?

The intake valve seat of the Vortec head has a three-angle grind straight from the factory and the combustion chamber design is a radical departure from former GM heads utilized in the market. The Vortec combustion chamber is a kidney-shaped design that promotes better combustion and will have the spark plug located near the center of the chamber.

The intake valve seat of the Vortec head has a three-angle grind straight from the factory and the combustion chamber design is a radical departure from former GM heads utilized in the market. The Vortec combustion chamber is a kidney-shaped design that promotes better combustion and will have the spark plug located near the center of the chamber.

The top two bolt holes were closer together than the lower bolt holes. Valve covers were made with bolt holes to match. In 1959, the valve cover holes in the heads were changed so that the holes were the same distance from one another across the top when compared to the lower holes.

When did Ford change cylinder heads and valvetrains?

Beginning May 2, 1966, Ford changed both cylinder heads and valvetrains on 289 engines. Prior to this date in production, Ford had pushrod guide holes machined into the castings. However, from May 2, 1966 on, Ford found a cheaper way to make 289 engines.

The spring retainers, keepers and other hardware is likewise inspected. Any worn or damaged components are replaced. New valve guide seals are always used. The valves are then installed in the head and shimmed to restore proper valve height. This is necessary because machining the valves and seat alters their dimensions.