H95

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Revision as of 09:49, 26 June 2012

H95 was a Small-Oval Shrouded-port Cylinder Head, used on USA engines 1981-1982 (A12A/A14/A15).

Overview

They were the ONLY heads for 1981 and 1982 in USA. So they are very common. Most guys want the high-power heads, so these high-torque ones are very available.

Small oval with swirl obstruction. These are good for emissions and fuel economy (H95 head, 1981-1982 USA all engines). They make excellent power at midrange RPMs.

This head does not have the air injection ports in the exhaust valve pockets. The air injection was done via the exhaust manifold using the pulsing of the exhaust to draw air through stainless steel pipes that were connected to reed valves in the air cleaner can.

Valves

• Intake: 37mm, 100.0 mm
• Exhaust: 30mm, 100.0 mm

All other A-series valves are 103.8 mm long

Ports

H95 Oval: 28x30 mm
H89 Oval: 28x34 - typical A14/A15
A12 GX Oval: 30x36

• Small-oval ports, guide is shrouded

Has what some call a "swirl" port has an obstruction cast into the port to cause the flow to swirl although it reduces peak flow. If you look into the port, from the manifold side, you'll see a heavily shrouded port, and looks much smaller than it would normally be on an A14 head.

Some say it can be ported very well, to very high flow rates.

Others have said if you try to grind out this obstruction, you will hit a water jacket and render the head useless. It too, has the coolant holes in it.

Manifold

• wet intake, Small oval ports
• 14035-H8901 manifold gasket (same as Large Size ports)

Head

Has an H95 cast into it, under the valve cover area

11041-H9500 A15 (H95 over #4 spark plug)

Combustion Chamber

They also have a small but deep combustion chamber, hence a different dish in the piston.

• peanut-shaped combustion chambers

H95: 35cc (A15 dish: 6cc)

D: heavily shrouded late-model design (H95)

EGR

Like any late-model engine, H95 had EGR.