Draft tube / crankcase vent

AnthonyG

AnthonyG

Well-known member
as Ive only had a '49 8BA engine and am working on cleaning up the mess from the draft tube under the car, ( setting up PCV ) and was curious, is the stock setup the same on the earlier 59A's? Did they have a draft tube venting the crankcase downward?
 
Starting in '35, fresh air entered the rear of the intake through the oil fill/breather, flowed down into the crankcase, then up into the valve chest and finally down a front located vertical stand pipe and directly out a vent (road draft) on the oil pan. The '49-up engines had fresh air enter the breather/oil fill at the front of the intake, flowing through the valve chest, down into the crankcase, then up to intake through a vertical stand pipe and into the road draft tubing.
The front mounted stand pipes were located in the same location, but ventilation ran in opposite directions.
 
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AnthonyG said:
as Ive only had a '49 8BA engine and am working on cleaning up the mess from the draft tube under the car, ( setting up PCV ) and was curious, is the stock setup the same on the earlier 59A's? Did they have a draft tube venting the crankcase downward?
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Tony. I've read you post 2 3 times and cant figure out if you are trying to put a PCV on an 8BA or 59A, V8 Bob has answered you question, tell us what engine you working on and we tell you how to hook up a DCV . Walt
 
I'm in the process of rebuilding a '49-'53 Mercury engine (.125 over=276) and would like to read of anyone's successful adaptation of a PVC system, in lieu of the old draft tube.
 
Hi Walt D, I have an 8ba and did the pcv setup by modifying the draft tube to a pcv then to a vacuum source on Center driver side of a Offy manifold. As the only Flatty I've worked on is my 8ba which I installed in my '35 I was just curious about how the 59A was different.
My pcv setup needs some tuning as the engine at idle rpm is all over the place. To keep it neat I went with a 90 degree pcv for an Accurate integral 4 cyl. and the spring pressure controlling the vacuum isn't right. I just ordereld a generic one for V8 street rod hopefully works better
 
I eliminated the tube by putting a 1965 289 PCV in the same draft tube hole and ran a hose from it to the base of the carb. (I put a Edelbrock 4 barrel intake and carb on it)
 
Notadurus ---Tony, the 8ba is easy to install a pcv valve, remove the breather pipe on the front of the intake, get an 1-1/4 rocker cover grommet that takes a pcv, use a pcv close to the same CI as you engine that will fit in the grommet, I like to get one that has a 90* on the top for the hose, I usually drill a hole in the side of the intake (with it off the engine) tap a thread for a 9* fitting for the hose, you usually only need about 6-8 inch hose and it lays low and hardly notice it. NOW, the 59 engine is a little harder, there is a no. of ways to install one, I'll tell you an easy way, not quite as neat, plug the slot in the breather on the bottom front of the oil pan, (this is easier to do with the pan off) drill a hole in the side of the breather, brass a fitting that the pcv will fit, find a vacuum spot in the intake and run a hose, if you can hide the hose it will work fine. Walt
 
Thx guys, the new chrome V8 generic PCV came, engine smoothed right out. Walts remark about PCV from similar engine was the trick.
use a pcv close to the same CI
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. Just needed a stronger spring in the PCV valve.
:D
 
Use something like the south wind heater vacuum fitting, this fits between the carb and manifold and drew vacuum from both runners, they turn up often on ebay. Of course you'll need to space up the other carbs the same amount to stop it looking funky.
Martin.
 
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