Manifold Exhaust & Intake – Non-Supercharged

Posted On: February 27, 2015

Intake and exhaust manifold: we have found green paint on the intake, but never any on the exhaust for obvious reasons. It is possible that these were painted off the engine together or possible they were painted on the engine as an assembly. This would mean the studs, nuts and lock washers would all have evidence of green paint, but we have not found that.

RESTORATION TIP: Knowing that the paint will burn off the exhaust manifold, I would suggest a ceramic coating that takes on the appearance of cast iron. Various companies provide this.

There are three different intake exhaust manifold combinations for non-supercharged engines.

For purposes of discussion we will consider the intake and exhaust manifold together as one part.

The heater valve or heat riser will be covered later.

850X used a Swan manifold A90302 for the exhaust and A90416 for intake. This combination would interchange with other 8 cylinder engines as well.

850Y, 851, 852 uses A90414 exhaust and A90465 intake.

All 652X, 652Y, 653, 654 use A90438 exhaust and A90443 intake.

850X uses three gaskets between the block and the manifolds. A5-274 front. A5-275 rear. A90310 center.

850Y, 851, 852 use gasket A90468 front and rear. A90469 center.

All 6 cyl use one gasket A90444.

There is a gasket in between the exhaust manifold and intake manifold. This area is known as the hot spot.
850X uses A90312.
850Y, 851, 852 use A90456.
All 6 cy use A90443.

Manifolds are bolted together.
850X uses four SA 612 cap screws
850Y, 851, 852 and all 6 cyl use four SA610 cap screws.
Screw heads are marked 30.
Lock washers are used with all these fasteners.