What is the meaning of "extreme rear position" of the downdraft tube under the manifold?

[Fernando Mendes]

"Extreme rear position" crankcase ventilation tube??

[9 foot box]

   It means that with the draft tube installed on the engine, you loosen the bolt holding the draft tube and point the tube down and back as far as it will go before hitting the bell housing. Tighten the bolt to hold it in place. When the truck is in motion it helps to create a vacuum to pull the fumes and vapors from the crankcase. Rick D.

[Fernando Mendes]

My IND-251 only has a cap in the oil filler.It has the downdraft tube under the exhaust manifold too.

[Fernando Mendes]

9 foot box.I think my tube is correct.

[9 foot box]

   The diagonal cut at the bottom of the tube, helps to keep a positive flow. I guess on a stationary engine, the flow would be created by the fan, when ran up to operation speed. I would suggest that you rethink your fuel line from the pressure side of the pump to the carburetor. If that second picture is a picture of your engine. Rick D.

[Fernando Mendes]

My fuel line CARTER pump(original) to CARTER E7T2 B&B carburetor with CARTER filter since april 2019.Before I used a brazilian DFV carburetor during 32 years.

[lostviking]

Unless it's a show truck, I would seriously consider going to the PowerWagon website and getting the PCV upgrade the military put in.

[greg g]

Copper tubing is not recommended for fuel line. It is known to be prone to brittle with vibration.  How long does this take?  I have no idea. But have seen it on an old garden tractor.  Tube split and began to leak.  Keep your eye on it.  The new brake line stuff might be a better material, almost as easy to bend as copper.

 

As for the road drft tube, both my engines had it mounted very close to vertical.  I have seen them mounted angled back toward the foot well.  Seems to me that would lessen the area where the low pressure area develops.