What Is A Draft Tube?

[DENNISJR60]

AND HOW DO I KNOW IF I HAVE ONE?

THANKS GUYS:confused:

[IgnitionMan]

Aha, Road Draft Tube, vent for the crankcase, valley and valve cover areas. Look down at the driver's side of the distributor, just to its side. If there is a road draft tube, it will connect to the block, then snake its way down the side of the block, open to atmosphere.

If you have a PCV valve type system, there shouldn't be a road draft tube.

[bobs409]

Used on 1962 and older 348/409's. And this is what the little critter looks like: :D

http://www.348-409.com/images/ref17.jpg

[droptop62]

Huh!
That 1958 348 tri-power motor I recently bought out of the junkyard had
the road draft tube on it. I had never seen one before a couple of weeks ago.

here is a reproduction on Ebay
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2414343607

[DENNISJR60]

SO WHAT HAPPENS IF I DON'T HAVE ONE? IF I DO GET ONE CAN IT BE PUT IN WITH THE ENGINE IN THE CAR? (PLEASE SAY YES):confused:

[dq409]

And I thought a "Draft Tube" was my throat when I`m drinking beer !! LOL

Go with the PCV system,,,,,dq

[dq409]

PCV installed

[DENNISJR60]

HOW DOES THE PVC SYSTEM WORK AND IS IT EXPENSIVE. I'M STILL WONDERING WHAT HAPPENS IF YOU DON'T HAVE ONE? IS THE PVC EASY TO INSTALL? THANKS:confused:

[IgnitionMan]

The part shown is not the regular PCV valve mount point, but the replacement fitting used after road draft tubes were eliminated, and has a hose attached to it, that goes into tghe underside of the air filter, to pick up clean, filtgered air for the rest of the PCV system. It can be used as in the pic, but that isn't the first way it was designed.

As far as the rest of the system, there were oil filler tubes that had/have both a sealed filler cap and threaded bung on the tuber side. The sealed filler cap closes the system off, the threaded bung was for a screw-in PCV valve into the tube, and then a hose fro the valve to the front of the carb.

1964 small blocks had the threaded oil filler tube, earlier ones had a hose nipple fitting that uses an inline PCV valve, with hose nipples on both ends, lays on its side, early Chevelle uses this type filler tube/PCV valve.

[dq409]

Dennis, I don`t think I have more then ten bucks in the whole setup,,,,,I had the road tube fitting already.
Parts:
90* PCV valve
PCV grommet (sized to fit tube)
PCV hose to carb (rear of front carb)

All part can be found at any parts house,,,dq

[DENNISJR60]

dq409,

I'M SORRY TO SOUND STUPID, BUT IF I NEED TO START FROM GO BEING I JUST HAVE A HOLE THERE WHAT EXACTLY WOULD I NEED?
90* PCV VALVE?

PCV GROMMETT? (DO YOU KNOW WHAT SIZE AND IS THIS JUST RUBBER?_

PCV HOSE TO THE CARB (WHAT SIZE AND TO WHERE ON THE CARB?)

I HOPE YOU CAN HELP BECAUSE I HAVE NOTHING BUT A HOLE THERE AND DIDN'T EVEN KNOW ANYTHING WENT THERE.

YOU DON'T HAVE TO ANSWER IF YOU FEEL I'M ASKING TOO MUCH

THANKS!





:confused: :confused:

[fatride]

An early big block Chevy valve cover grommet (1.250 diameter) and 90° PCV into the back of the intake where the draft tube went with a rubber hose to a fitting in the back of the rear carb will get rid of the messy vent tube at the firewall.

[dq409]

You can never ask too much here,,,,,besides what would I do on my breaks ! I have been working at home on the house so I do take LOTS of breaks !!!

On to your questions,,,,,
(1) first you need the part from the draft tube thats goes in the back of the manifold,,might try posting a want for one here.

(2) then you take it to the parts store and get the grommet (rubber) that fits and the PCV valve and the hose.

Depending on what carbs you have ther should be a large vac port on the rear of it. It might have a plug in it you might have to remove and add the port tube. Edelbrocks all have these and the parts.

Go to a GOOD independent auto parts store, not a SCHUCKS !! Ask for help and let them know what your doing and looking for.,,,dq

[dq409]

FAT,, YOU WERE FASTER !!! dang,,,, Sooooo,,,,the valve cover grommet will work,,,,,,,DOH !! thats go to know,,,,dq

[fatride]

You don't need the draft tube at all. The grommet will fit right where the draft tube goes, right into the intake manifold.

[DENNISJR60]

OK GUYS HERE'S WHAT I DID I GOT THE GROMMET AND THE PCV VALVE AND I PUT THEM IN THE HOLE ON THE BACK OF THE INTAKE AND I RAN A LINE FROM THE PCV VALVE TO THE PORT ON THE SIDE OF MY CARB. IS THIS RIGHT? JUST FOR NOTE THE PORT ON THE CARB THAT I RAN THE HOSE FROM THE PCV VALVE TO IS SUCKING AIR WHEN I PULL THE HOSE OFF. DOES EVERYTHING SOUND RIGHT?

THANKS!

[fatride]

Yep, that should do it.:D

[Bungy]

Does it matter if the PCV valve is vetical or horizontal? Or doesn't it make a difference?

[ElkyBob]

I got this from a post from the old BB just last week after spendin g bout an hour looking for it, probably one of DQ's, but I'm not sure. Anyway the grommet is from the HELP section of any auto parts store, the part number is 42048. The PCV valve number I have is for a Fram, FV184. Get the PCV valve then you can get some hose to fit it while you are at the store. Hope this helps. ElkyBob. :cheers

[dq409]

Bungy,,,Nope doesn`t matter,,,,

[DENNISJR60]

THE PART NUMBERS I WAS TOLD TO USE ARE "HELP" #42048 AND PUROLATOR #PV774 AND EVEYTHING FITS GREAT.

[tripowerguy]

Bunch of young whipper snappers whats wrong with a draft tube. We build these engines so they don't smoke.:rolleyes: Roy