HoosierDaddy

This was originally a slightly off topic post in a thread about S550 GT drain plugs. But it's really a separate topic that applies to all cars and 99.5% directly applies to all S197 or S550 Mustangs. Different oil pan threads may apply to earlier Mustangs.

I used Fumoto oil drain valves in all my cars for decades and they are a huge improvement over a drain plug. But I switched to Femcos on my new cars when I discovered them in 2013. They are based in the Netherlands and invented this type of drain valve and have been making them for over 40 years. Their target customers are primarily fleet owners. I don't think they feel enough regular folks would buy any valve because 99% of owners don't change their own oil and just take it to the dealer or JiffyLube.

Anyway, advantages of pretty much any oil drain valve:

Advantages:

• They eliminate the chance of stripping drain plug threads or drain plug gaskets leaking.
• They make oil changes easier and much cleaner since they allow the use of a hose from the valve to a container. Many don't even require a tool to operate.
• They make it simple to extract a small amount of oil for analysis.
• If you use extra oil in a vehicle on track days (my Cadillac requires that, for example), it makes it easy to remove the extra.

Common drain valve downsides:

• For vertical orientations, a slightly less amount oil can be drained if the valves threads are longer than the thickness of the oil pan. And for horizontal orientation the valve itself will make the opening smaller and therefore slightly higher - imagine the original horizontal drain plug with a hole drilled thru it for the oil to drain.
• For vertical installations, the valve may extend down farther than the drain plug it replaces. If the drain plug was susceptible to impacts, a valve could be even more. I have a relative who tore a vertical Fumoto valve off a Yaras when they drove over one of those concrete parking lot stops. I'm guessing a drain plug might have survived, same for a compact Femco.
• Since all valves occupy some of the drain hole in the oil pan, it will take slightly longer to drain the oil. So no need to rush that beer.

Fumotos are simple quarter turn ball valves. They have the above advantages but also have additional downsides including single point of failure for leaks, relatively difficult to open/close as a deterrent to accidental opening, may need to operate with gloves since the valve handle is the same temperature as engine oil. Some are very minor downsides, but still downsides. Fumotos are relatively easy to find and buy because personal vehicle owners are a target audience.

Femcos eliminate the down sides of the Fumotos but may have others, including the need to carefully chose the type of Femco valve that will work for your future vehicles. Get it wrong and you may have to buy a different style drainer (explained later). Femcos operate similarly to an intake or exhaust valve. And like those, its normally held closed by a strong spring. When closed, they prevent oil from passing with the help of an o-ring. And like an engine valve, its opened by pushing on the stem. There are different types of Femcos, but the most common open the valve when a drainer is screwed onto the valve. Other, more expensive types, have a drainer that just pushes onto the valve like an air hose quick release. Might make sense if you're paying a mechanic to operate the drainer but for home use, not so much.

Femcos that use screw on drainers to open the valve are available in 2 widths (LB - Large Base and SB - Small Base) and 2 lengths (standard and compact). The Large Base isn't relevant for passenger vehicles, it's pretty much only needed for larger industrial engines. I'm just speculating but I suspect the Standard length type of valve was the original concept and they keep offering them. I can't see much advantage of a physically longer valve. So I think the SB Compact valves makes the most sense for passenger vehicles.

Here are some pictures I took of an SB Standard Femco for an S550 Mustang. I ended up exchanging this for an SB Compact but didn't take as many pictures of that one. The pictures do show the quality of construction and how the valves operate. But the SB Compact valve doesn't stick much farther out of the pan than the factory Mustang drain plugs (1/8 inch more max, but might even be shorter than the plug). The 22mm hex (used only once to install the valve) is about half as thick as these pictures and the cap is even smaller than half of the one in these pictures.

Each type of valve comes in pretty much any pan thread size in use in passenger vehicles. And they offer various length of the threads that screw into the pan. For vertical drains, you'll want threads as close as possible to the thickness of the pan so as not to raise the opening the oil has to drain thru. For horizontal, it won't matter. 9mm long threads are best for an S550 GT, since they won't extend beyond the thickness of the pan. For a V6 or Ecoboost, longer threads wouldn't hurt since its horizontal. BUT, the V6 and Ecoboost have fins and machined areas on the outside of the pan and I can't swear those won't interfere with installing the valve, even though it seems likely they will fit.

Below is the part that threads into the oil pan. The valve is closed. A later picture shows the valve open. Remember this is a Standard length valve but the best for the S550 is the Compact type with the much shorter body.



Below is the other side of the valve with the knurled cap removed so you can see the plunger that opens the valve when the "drainer" is screwed onto it.



The following is a "drainer". To drain oil, you remove the knurled cap from the valve and hand screw this on in its place. As it tightens, it pushes the valve open. The hose spins free to make use easier. The same drainer will work with all valves of the same type (ex: all Small Base Compact valves). But the first vehicle you equip with a Femco valve will involve purchasing a "drainer". Additional and future vehicles can all share the same "drainer" IF you buy the same base and length type of valve. The seemingly large diameter of the drainer side of the valve is so that one "drainer" can be used with a very wide range of drain thread sizes.



Below is the valve with the "drainer" screwed into it so you can see the valve in its open state inside the oil pan.



Below is a picture of the SB Compact Femco I am using in my GT next to the factory drain plug. They are to the same scale to show how much each extends outside the pan and inside the pan. This picture doesn't have the dust cap on the valve, so mentally add about one more thread to get a feel for how far it will extend from the pan. If I knew in advance I was going to make a side by side pic I would have taken one with the cap on (and with the copper washer).



FYI, the Femco part number for an SB Compact valve with M12 x 1.75 threads 9mm long is 7090010153. If I had a V6 or Ecoboost, I might want to order one with longer threads than 9mm.

Link to order from the US branch: http://www.femcodrainplug.com/fcart/...product_id=234

Link to order from the manufacturer in the Netherlands in US dollars: https://www.drainplug.com/usa/compac...090010153.html

One is more expensive for the valve while the other is more expensive for the drainer. I went with the US branch for local support.

FYI, anyone installing any brand of valve, remember to use the lower of the drain plug and the valve manufacturer torque specs. For a new GT, the Femco valve has a torque spec of 12 ft.lb while the drain plug calls for 19 ft.lb so 12 is the correct setting for your torque wrench.

Of course unlike the drain plug, you only screw the valve in ONE time instead of every oil change.