The Ford Barn

Bored&Stroked · 04-23-2023, 09:26 AM

It is important to understand how the original road-draft/vent system works. The road-draft vacuum was pulled from the front of the manifold - which connected to the upright draft tube from down in the crankcase. This pulls combustion gasses and water vapor from down in the crankcase (not from the valley area). The example above still accomplishes this - which ensures the system works as close to possible as it should (on a later 49-53 engine).

On a 59X block, you also need to run the oil-baffle tube in the rear of the intake - which is usually missing. This directs the incoming air down into the crankcase. Also on a 59X block, you need to weld up the original oil-pan vent that pulled vapors out the pan itself. I question how well this system worked in the first place . . . though it was great for "chassis lubrication".

If you decide to retrofit an earlier manifold onto a later 49-53 engine, then the RIGHT way to pull the vacuum is from the same upright crankcase ventilation tube in the front of the engine. I would take the tube out, weld the top-closed and mount a PCV in the side of it.

You have to make sure the PCV you use is designed to be mounted in whatever position you fabricate/rework the front to encompass it. Some PCVs have to be vertically oriented (at a slight angle - like a valve cover) - some are designed for a horizontal mount, etc. I like the adjustable one shown in the above setup - though it would be a bit hard to "adjust it" when you can't get to it. There are creative ways to use it - but it takes more fabrication and custom parts to do it (to place it down in the valley).

The system from CoopMan is a very well thought out system as well . . . so plenty of ways to skin the cat!

04-23-2023, 09:26 AM	#1
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,723	Re: Flat Head V8 PCV valve question for you? It is important to understand how the original road-draft/vent system works. The road-draft vacuum was pulled from the front of the manifold - which connected to the upright draft tube from down in the crankcase. This pulls combustion gasses and water vapor from down in the crankcase (not from the valley area). The example above still accomplishes this - which ensures the system works as close to possible as it should (on a later 49-53 engine). On a 59X block, you also need to run the oil-baffle tube in the rear of the intake - which is usually missing. This directs the incoming air down into the crankcase. Also on a 59X block, you need to weld up the original oil-pan vent that pulled vapors out the pan itself. I question how well this system worked in the first place . . . though it was great for "chassis lubrication". If you decide to retrofit an earlier manifold onto a later 49-53 engine, then the RIGHT way to pull the vacuum is from the same upright crankcase ventilation tube in the front of the engine. I would take the tube out, weld the top-closed and mount a PCV in the side of it. You have to make sure the PCV you use is designed to be mounted in whatever position you fabricate/rework the front to encompass it. Some PCVs have to be vertically oriented (at a slight angle - like a valve cover) - some are designed for a horizontal mount, etc. I like the adjustable one shown in the above setup - though it would be a bit hard to "adjust it" when you can't get to it. There are creative ways to use it - but it takes more fabrication and custom parts to do it (to place it down in the valley). The system from CoopMan is a very well thought out system as well . . . so plenty of ways to skin the cat!