So...I've searched multiple threads, forums, and articles and I'm still a bit confused as the information I've read doesn't make a ton of sense to this novice. I'm restoring a 53 F100 and have transplanted a 292 out of a 59 F100. I'm hoping by posting some pictures you fine folks can help me make some progress on finishing the plumbing on this engine. I've had this motor fully rebuilt but I'm not real sure if I need to install a draft tube or a PCV set up. Also, I'm not completely sure how I would approach doing so given the current set up. Pictures would be helpful if possible. Thanks for helping point me in the right direction.

 

there should be a vent tube running down one side of block to let blow by out,i have seen tube coming out of oil filler tube or tube coming out of oil fill cap,

 

My 59 F250 292 has the road draft tube on the front driver's side of the block, about straight behind the fuel pump. It does look like yours exited the valley pan. There is no reason you couldn't put a pcv valve in there if that's what you want. You will need a carb spacer with the provision for it.

 

that's a nice looking motor,i ran the 3 2bbl carbs on mine with 3spd overdrive back in the day,

 

Nice looking motor. It looks like the same set up as my 1960. The big hole in the valley cover near the distributor is where the original draft tube would have gone. It is just a piece of tubing that ran down the back of the motor and as you drove down the road, the wind across the end of the tube created a slight vacuum on the engine and vented the blow by. The picture below shows the draft tube. Note I converted to a 4 BBL, so it is not exactly the same, but the rest of the engine is the same.

Later I made a rubber grommet for that hole and fit a PCV valve in it and ran a hose to the vacuum connection near the bottom of the carburetor. The connection on the intake manifold in your first picture. This has worked well. You do have to make sure that you oil fill tube cap is vented.

 

One other thing. If you have the original draft tube, it is even easier. You can cut the tube right before the first 90 degree turn and then fit the PCV valve into the tube. This can be done with a piece of rubber hose on the outside of the PCV valve. This maintains the connection to the valley cover and is easier than making a bid rubber grommet that fits the PCV and the valley hole. HTH

 

Thanks for all the info. This is very helpful in clearing things up for me. Couple follow ups...

If I happen to locate an original draft tube would the valley pan have to be removed in order to install it?

It sounds though that the better thing to do is to make a rubber grommet that would pop into the valley hole and install a PCV that would then run to intake vacuum port under my carb. If I go that route would I then use the vacuum port on the carb (currently it has a plug in it which you can see in the last picture) for the vacuum advance on the distributor?

Thanks!

 

You can install the draft tube without removing the valley cover. However, if you don't have it, I would just make a grommet to fit the valley pan hole that accepts the PCV.

Where you hook the vacuum doesn't matter all that much. I hooked my PCV to the extra port on the carb. You could also tee the other one.

 

No, the vacuum port for the distributor won't work. For one thing it's way too small and should be ported which means it only has vacuum as the throttle plates open and you will need it for the vacuum advance anyway if you are running the stock distibutor. You could probably go to the one in the manifold in front of the carburetor.

 

I assume the flat head screw stays in the valley hole when doing this pcv mod, correct? It's simply just pop something like this in?

 

PCV introduced in 1961, was mandatory in sold new in CA vehicles, but it wasn't until 1966 that all states required PCV

 

the vent tube that runs down the block needs to be in place it helps vent the engine from blow by,if not soon you will start having oil leaks,i seen hose from the oil filler tube ran over to top tube of air cleaner,some have the tube attached to the oil filler cap,that's how my 59 292 was,

 

Without some sort of pcv valve, just a tube like that can allow gas vapors back into the crankcase. One backfire and your oil pan will hold a few extra quarts and you'll be looking for new valve covers to replace the ones you blew out. Seen it happen

 

vent tube running down side block vents the engine,again hose from oil filler tube to air cleaner or oil filler cap,you didn't understand me,some y block have a tube attached to side of oil filler tube that a hose gos over it and ran to air cleaner,some have the tube attached in the oil filler cap,all blow by gets burned by the engine as its mixed air/fuel,no pcv valve is needed,this is original to the yblock,if engine isn't vented were would blow by go,it would cause a leak.

 

Here is what I'm thinking...let me know if there are issues with the approach. Install the pictured grommet/PCV valve that I made leaving the flat head screw in the valley hole in place. Install a tube from the PCV to the currently plugged vacuum port on the carb. Install a tube from the vacuum port on the intake to the distributor. Does that sound like the right approach here? Thanks all!