road draft tube

Iv'e got a 1950 Ford F-1 with a stock 8BA and Iwant to change it to PCV.What do I need to go in the draft tube hole in the block?And what kind of valve? Thanks Jim

 

IF you are insistant on changing to PCV weld a pipe nipple into a freeze plug that fits the road draft tube hole and use an in line hose type PCV valve, make sure PCV valve and plumbing aligned as not to allow puddling aka kitchen sink trap. good luck!

 

I took a couple of pieces of copper pipe. I have pics but I can't upload them from work. Essentially it's this.

Copper fitting that fits inside the road draft tube loosely, mine was like a inside/outside straight section for connecting different sized copper pipe. Don't really remember the size but it was bigger on the outside and smaller on the side that went into the draft tube hole. Then I got a bigger copper cap for the big end and jb welded them together. Got a drill and poked a hole in the center of the cap and drilled it out to fit a grommet and a cheapo pcv valve (90 degree) into it. Inside, I got a little mesh filter from the help section of the parts store. It's a little steel biscuit with some stainless steel wool inside and two mesh faces on each side of the biscuit. I am pretty sure I had the copper pieces before I got the biscuit that "just" slid inside the little part that goes in the draft tube hole. I JB welded it in as well. Then I got some rtv and ran a bead and let it set up a little until I made a "o-ring" on the going in part. Once it fit snugly, I put a little more on it and shoved it in the hole. Ran a vacuum line to the port under the carb. Done.

If I can find the pics when I get home, I will post them up later. It was a day of running to Lowe's for plumbing parts and then the parts store for the breather biscuit, pcv valve and rubber hose. It works perfectly.

 

You need one of these. Then get a fitting that screws in the side, some 1/2" copper or steel tube, make a brass PCV valve, plumb it into your inlet manifold plenum and Bob's your uncle. It will look like it's meant to be there. They were used on some Dodge flatheads (trucks or power wagons I think), although not finned like mine.

The dimensions of yours may be different.

 

I'm not much into kits but there was someone selling a PCV valve kit for the 8BA that uses a readily available PCV valve rubber grommet and valve that goes into the road draft tube hole in the manifold. A hose to a vacuum source close to carb and it's done. About as simple as it gets. Measure the hole and check some PCV grommets to do it yourself cheaper.

 

All of the above and remember to guy the actual PCV for an engine close to the cubic inches of the motor you put it on. It can affect the idle if not close.

 

Even if you get one that is close, you will have to adjust the idle screws some. It is a controlled vacuum leak so the carb will need adjusting.

 

Why not just run the road draft tube? A PVC valve is not going to give you better performance.

 

All of the above for the PCV part of it, but as for plugging the hole I would press in a freeze plug. I did that on an early SBC intake, doesn't look bad at all. A road draft tube is kinda unsightly

 

There is a reason that the OEMs switched to them before it was a nationwide mandate, engines do better w/o crap acumulating in the oil pan that gets sucked out with the PCV.

 

OK, posting these up. Pardon the old, dirty engine. It'll get fixed when I eventually rebuild it. For now, it runs and drives and I don't have to push it from place to place until I get the 55 F600 off the project list and can put the 52 on the front burner.

Parts are help part number 47064 breather and 42058 pcv valve grommet and copper fittings. I don't remember the part number for the pcv valve but I just grabbed one with 3/8 fitting and that fit that grommet.

Hope the pics explain.







Sometime before this I "made" an o-ring with silicone and then siliconed it in. In retrospect, I could have just stuck a freeze plug in upside down after making the same hole and put in the same grommet. I like to make things more difficult than they have to be though...

 

Just remember, whats going out the road draft tube you are now sucking into your combustion chambers......If you run a PCV valve you will also need a breather to draw in clean air. Most run it from the air cleaner housing after the filter.