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I have installed a simple crankcase draught system on my 327 in line 8. I noticed after driving that smoke would rise from the oil filler tube. Add to that the co-pilot (Shelley) detests the smell of gas. Both of these are normal with old cars but not acceptable to my bride and I figured there was room for improvement!
To try and make riding in the car more pleasant I added this system.
I had a left over cooling fan from an old computer in my junk drawer, (we all have those, what my Grandpa called good junk, probably never use it but too good to throw away!)
I cut off the 4 pin connector and skinned the wires to determine; which two ran the fan? if it would run on 6V? and which was hot and ground?
Once all that was figured out I laid the fan on some Bristol board and laid out a bracket design that the fan would fasten too and attach to the engine block. I found that a good spot was in concert with the mounting bolts that hold on the oil by-pass filter. This puts the unit right in behind the fan and radiator getting a good air supply and in-line with the existing hole in the oil cap that the engineers were using to draw passive air through the crankcase in the first place.





I connected the positive black wire to the bracket as this car is positive ground, and ran a red wire from the coil connection to the red wire on the fan so it is powered on when the key is in the 'on' position. No need for a switch as it is a low draw fan and you always want draught going through the crankcase while running anyway. (I also found the fan must already have a diode inline somewhere as it only runs in one current layout, this way the fan could never run the wrong way if hooked up improperly.)
To the fan bracket, behind the fan, I added a plastic funnel to concentrate the air from the fan into the intake slot on the oil cap. Both the bracket and the funnel were shot with some black spray paint to better blend the assembly in with the rest of the under hood components. I also added some braided tube (used for wire looms) to the end of the funnel and inserted this inside the slot on the oil cap. This way you can still remove the oil cap as the braided tube flexes out of the way easily.








On the out flow side I removed the road draught tube and inserted a grommet that filled the ID of the pipe nipple, and also allowed the insertion of a 5/16 steel tube through its centre, (I used the same tubing that I used for the fuel line).





To this line I added a catch jar in case any oil was sucked through the draught line. It is a salsa jar with a steel cap. I simply soldered a 6" line bent at 90 degrees at a 12 o'clock position, and a 6" straight one at the 6 o'clock position to the jar's lid. Using gas line hose the bent line is attached to the road draught line, and the straight line has the hose run up to the inner area of the air cleaner to add to the air's intake draught.













Now the crankcase air is actively pulled through the system and back into the intake of the carb ridding the fumes from the interior of the car. If any oil shows up the jar can be removed and drained. Many trips so far and no oil has shown up, and there is very little gas smell anymore. Also no smoke rising from the oil filler tube even after a long hot run, and the engine runs cooler as the crankcase is getting fresh cool air more directly than the original passive system, especially at an idle.
Bob J.

That’s an interesting solution! Somewhere here on this site in another thread where someone did a similar system but, as I recall, it was more passive as I don’t remember it using a fan. That said, if fumes are getting inside the car, best to find where they are getting in as that should never happen even with the windows open. Do check your air cleaner too as its small size over the original may create restrictions that make the engine run richer than it should.

Once again Don you have parsed an error in my description. It is appreciated and I want to make it clearer.
The fumes from the crankcase do come into the car, the floor is sealed and so is the firewall, but it still persisted as fumes are very light and do rise. Maybe acerbated due to it being a convertible. It was recognized decades ago and engines were changed to remove this from happening, as the old road draught tube emptied right below the passenger's side of the car. This was very noticeable to my wife especially when stopped at an idle.
This is what I wanted to remove from the riding experience. (Back in the day it was common place, maybe because everybody smoked anyway so what was the difference? I know my Dad sure did!)
The need to rid the engine of this smog is why the engineers of the day put the draught tube in the engine in the first place. It is why there is a vent on the oil cap along with an oil soaked wire mesh filter in the cap too, to try and exchange the fouled air in the crankcase, caused by minor piston blow-by as a result of internal combustion, with fresh.
This system can do so a little more actively and passively and give the fouled air a place to go back into the engine without putting a modern PCV valve into the mix and messing with the vacuum side of the engine.
Rest assured I did my due diligence, the air cleaner on the car works fine, there is no richness added to the mixture, the exhaust out of the tailpipe is clear with no raw gas smell. Sparkplugs are clean with a nice tan look. I am sorry if I lead the readers to think otherwise.
Thanks,
Bob J.