Putting a PVC valve in a 170??

This is a GREAT post about putting a PCV valve in a 200, but couldn't find specifics on installing it into the 170.

https://vintage-vans.forumotion.com/t14416p15-got-the-blues-draft-tube-to-pcv-valve-conversion

Great post! I"ve had my 170 E100 for about 5 months now and while some think the smell gives it the Old time "character", but those if us from this century don't . My wife loves the uniquness of the ride (it is older than she is) but I have to 1) Get rid of the smell, and 2) install seat belts before she'll ride with me again.

As I see it, I just (somehow) connect the bottom of the venting tube that goes down the front left of the engine back up to the npt port in the manifold under the carb with a rubber hose? The pictures (in this post above) of the brass fittings at the carb are great. Exactly where and how is the appropriate Pcv "teed" into it? Would it Hang it upside down @ the bottom of the vent tube? (Does it matter if the actual pcv valve is right side up or upside down?) Then I just get a new air filter housing with a tube connection and connect it to a breather cap with a hose??? Would anyone have a part number or detailed spec that would identify a specific pcv that would be appropriate. I am planning on changing the air intake to a system that scoops from the outside and feeds into the carb anyway.

Does not sound too complicated, I guess it is just a physical mod, I mean the there is no "computer" to connect sensing wires too?

Jim, I never took a close look at the 170 amd how the draft tube is attached. But I believe that the examples I read about involved removing the draft tube and putting the PCV valve there. With the Ford Big Six, it was easier, because the draft tube is attached to the valve cover.

But really, when you see how much sludge is in a 50 year old engine, I think this mod makes sense. Take pics!

Will this modification create a problem with the sludge? Will it worked its way out without a major problem, or can I expect other issues?

If I understand your question correctly and if I remember how the 170/144 draft tube is connected a couple of things will need to be done.
You will need to mount a PCV valve in the valve cover and seal it with a grommet if possible. Some PCV's are spring loaded and some are not so that will be a consideration for the valve you use. I can't give you a part # right off. Then connect a hose from the valve to the brass fitting in the intake as pictured in the write up for the 240. The old draft tube will need to be blocked off or removed and the vent hole plugged to prevent dirt from being drawn back into the crankcase by the vacuum the PCV will create.
The valve covers for the 144/170/200/250 should all have the same bolt pattern and the 200/250 should already have the PCV mount in them. The trick is to find one, so the easiest route is to mod what you have so you may need to be a little creative.
As far as the sludge goes, adding a PCV will only help to slow the creation of sludge and won't remove what you already have. If you remove the valve cover and you see lots of crap in there the only way to get rid of it is to clean it out or run an engine flush. But a word of caution here, sometimes running engine flush can loosen broken valve seal pieces and plug your oil pump pick up. To be on the safe side you might just plumb in the PCV and leave it at that.

OldSkoolVannin wrote:Will this modification create a problem with the sludge? Will it worked its way out without a major problem, or can I expect other issues?

Sludge doesn't just accumulate because of not changing motor oil frequently. Sludge looks like burned oil, but it really only accumulates when The oil and combustion by-products basically combine in areas where there is no air flow (rocker valley, pushrod valley) so imagine when you are driving an old vehicle with a draft tube, idling in the city alot, no air flow to draw out the contaminated air sitting in the head, block and oil pan. Sludge is created and makes your valve train sticky. Same engine with PCV, no contaminants can accumulate, so oil not changed to sludge.

66ThunderVan wrote:
The valve covers for the 144/170/200/250 should all have the same bolt pattern and the 200/250 should already have the PCV mount in them. The trick is to find one, so the easiest route is to mod what you have so you may need to be a little creative.

I don't have the answer whether 200/250 have PCV bung or not. My valve cover on my 170 does not have a baffle that separates the front from the rear. The flow of air on that engine is to draw it in fresh through the valve cover air breather, which is drawn through the oil gallery holes in the head into the block anod out the draft tube (when air rushing past it creates a strong enough vacuum to suck out the crankcase air... doesn't happen except really at highway speed). Most direct location for PCV valve placement is where the draft tube presently is. See if I put a PCV valve in my 170 valve cover, air would flow directly from the air breather across the rockers and out, but force no flow through the crankcase. The 240 valve cover is blocked with a baffle, so air comes in the breather, forced into the engine block by the baffle, and back up to the other side of the valve cover and out... flow is forced through the crankcase.

On a V-engine, typically there is a hose that goes from one valve cover to the air cleaner. Fresh air enters there. The other valve cover contains the PCV valve with the hose that goes to the carb base. Imagine how the airflow travels through the crank case from valve cover to valve cover... so the Inline Six valve covers would need to have two zones to work. And I'm not sure that the Falcon Six heads and valve covers could be easily modified that way.

I find this VERY helpful, thank you. I like your logic and as I see it, it makes sense to attach the PCV to the Draft tube, then Valve cover baffeling is a non-issue and teh deraft tube IS the original design that addressed moving those gasses outta the 170 engine. I would think hoses & clamps would be adequate. Cut the vent tube as high as possible, attach to the bottom with a "U" fitting of some kind with a reduction to the PCV size. After coming up vertically from the (new) bottom of the tube eve with the top of the engine, install the PCV and then go on to a brass fitting configuration at the Exhaust mainifold (piggy back onto the 5/8" hot water hose out the Thermostat housing around the front and down the side). Then connect the Valve Cover Breather to the Air Cleaner. Seems logical, don't you think?

The brass fitting goes to the intake, not the exhaust. But yeah, you have the right idea. I cannot remember if there is a bung in the manifold, carb spacer plate, or even carburetor base. What's important is that it's ported below the carb so the charge at the carb remains fresh air/fuel mix.

The old style like what you probably have on your truck has an air breather-style oil filler cap, which takes the place of the newer style ones where the hose runs to the air cleaner and the fuzzy filter is held against the wall of the air cleaner housing outside of your air filter??? Know what I mean? Like this example...



I would use a breather-style oil filler cap like this (which is just a fancy version of the original), because you wouldn't need a hose to your air cleaner.