BritishV8 Forum

I got enough stainless mesh in to "hopefully" do the job. It's placed in the lower 3/4" ID hose section below the coupler to 5/8" hose which runs to the 90 degree coupler in the filter housing. From what I've read, you don't want restriction in flow, so we'll see how it goes once running. It's not packed in there.  With help found here, the PCV system is complete. Fuel system is connected with new filter and soft lines. Starter is in and connected. I can connect the distributor wires, install the coil and connect the plug wires.
I'm thinking the first start up is soon. It seems installing the Radiator and driveshaft should wait until after the initial fire up to confirm it runs. If it starts and runs, I'll connect the Rad and do a 20 minute break in. If I'm missing something, please chime in!

If you stick a wire through the hose and tie it to the end of the scrubber pad to pull it back through you will figure out pretty quick how much you can get in there.

Jim

So, the question is how much of the mesh and how far up the hose to place this stuff? Looking online, there are warnings that it could restrict flow if done incorrectly. Also its stated that it should be cleaned out periodically with solvent.

I think I have what I need except the 3/4" hose for the fuel pump block off plate and 3/8" hose for the PCV valve to intake. Coming tomorrow.  I found the right cap for the PCV in my stash of parts. I did get the spark plugs gapped and installed with anti-seize.

Thanks Jim! I'll look at what hose sizes I can get routed to the air filter housing underside.

It does but you also need a flame arrester/vapor trap in that line because without it a backfire can ignite gases in the crankcase and blow out the lifter valley tin. BTDT

There is enough room in the plate to go up to a 3/4" NPT thread which has a 1.050" OD. This gives room for the pot scrubber pad and the only down side is routing the hose. Silicon and pre-bent hoses are available though. With the pot scrubber nothing special is needed on the air filter end and oil drain back is very much downhill.

You can go smaller on the sizes and some will probably recommend that. I won't. It's no harder to make it larger than it is to make it smaller and this is a case where too large is only an issue if you can't fit it in the space available. Too small otoh can cause oil leaks.

Jim

Thanks guys! Jim are you talking about the fuel pump block off plate. Because I do have that plate with a 90 fitting. So I'll put that back on and run the hose under the air cleaner where I had the original valve cover vented to. Then I can attach a PCV valve to the cap with the tube and run it to the intake. Sound reasonable?

215s are commonly prone to blowby regardless of how meticulous you are in the build. It has to be allowed for in the crankcase vent system.

First and foremost, provide an escape path for  the combustion byproducts at max load and speed. Only then can you assemble an effective evacuation system for midrange and idle. The bare minimum is a clear and unobstructed 5/8" inner diameter and this will not be enough as the engine inevitably wears. It doesn't matter a lot where this line goes as long as it is open to atmosphere. Some choices are better than others. Road tube: not great. Valve cover vent: slightly better. Through the air cleaner base inside the filter with a flame trap: better. 3/4 ID tube: better still. Catch can: OK but completely unnecessary.

I like to come off the fuel filter mount block off plate with a 90 degree street L pipe fitting (stainless is available) and go vertical with a 1" ID hose. The cut off end of a threaded pipe of a suitable length works quite well here. That's big enough in cross section to pull half of a pot scrubber inside as a trap and drain the oil that condenses back into the crankcase and still have enough flow area. This configuration has worked well. Placing the outlet where the fumes follow the intake path is good practice but the outlet should not be obstructed in any way.

Once you have that in place it's fair game to configure the positive crankcase ventilation system. That's where the small line with the PCV valve comes in. It also can go anywhere although it is common if a valve cover vent line is used to plumb it to the opposite side. Other engines such as the B series use the tappet cover, etc. It needs to restrict or stop the flow at idle under high vacuum and allow full flow at moderate vacuum during cruise, whatever that happens to be for your engine. The carb or EFI is then calibrated for that air leak.

In practice this then blocks off air flow at idle so you can control your idle speed. It allows vacuum to pull vapors out of the crankcase at cruise and compensates for the airflow, and it allows the engine to ingest the blowby gases, with the fuel system tuned to accommodate the blowby content. Oil vapors are condensed and/or kept inside a sealed system.

Jim

PCV diagram:

That is the idea of the parts I recommended. Open vent on driver side and vent with tube to PCV on the passenger side is commonly used. If you have a little oil around the open breather you could go to another one with tube to go to the bottom of the air cleaner with a hose. The open breather should have what looks like a kitchen scrubber inside it. With no blowby, should have suction there.