Inspecting what I have

Lean CVH head.

I have the lean CVH head which is one of only 15% of the carb engines made after 1996. It has 6 BHP less than the Hemi CVH engine when carrying the slower TLD carb. The Hemi engine head with the DFT carb has around 96 bhp so mine should apparently have around 90 bhp at the flywheel which to me sounds a little optimistic so I would guess it would have around 88 bhp!




Inspecting the ports.

I will do a small gasket matching porting job on the engine before putting in into the car.

Being more sensitive than the exhaust manifolds I have read that the walls of the ports must be kept unpolished so that turbulence is created which mixes the fuel and air together. Polishing the sides will reduce performance. Matching the ports to the gasket is what I will do but the gasket I currently have seems to be the wrong gasket at the moment since it is way too big and doesn't match the oval shapes of my engine's ports.

Current port hole dimensions are as follows starting from the right port and ending at the left.

33x36mm

33x36mm

32x36mm

32,5x37mm

Seems they are uneven at the moment.

The inlet manifold's ports are smaller than the cylinder heads ports. I have read this is quite normal but still wonder if I was sold an inlet manifold which doesn't match my cylinder head. I will do a rough port job on both the cylinder head and the inlet manifold anyway. They will both match a gasket which I will buy tomorrow and should match these ports better than this current one.

Inlet manifold starting from left to right (matching the cylinder head).

30x34mm

30x34,5mm

30,5x33,5mm

30x33mm

There are huge differences in porthole sizes. Comparing cylinder 1's porthole sizes together gives 3mm difference in width meaning the air would suddenly enter a wider tube and a 3mm difference in height.

(I have read that some cvh porters have ported to 36mm diameter inlet ports on carb engines. They were using standard 42mm inlet valves. After measuring mine I got 40mm, maybe I measured wrong I will have to remeasure).