exhaust pipe on back of engine??

I have a 283 in my 62 chevy wagon, on the back of the engine, there is a pipe dumping exhaust exhaust to the ground. My mechanic said he's never seen anything like it, anyone have an idea about what this is and what it's for? Can it be plugged, removed, routed into the exhaust??

 

OOHHH, you have the rare 8.5 cylinder engine! When you smash the gas to the floor that extra pipe starts making some noise and smoke!

It all means POWER! WOOOO!



/sarc

Road draft tube

 

Draft tube?

 

Might not be the best person to be working on an old car! lol

^^ what they said...road draft tube!

 

hahahahahahaha.

 

It's called a draft tube and all SBC's had them up until about 1970. If the guy working on your car doesn't know what the tube is for, find someone else to work on it.

And know you can't plug it. It is the crankcase vent/pre PVC.

 

Your mechanic must not work on much old stuff.

 

I think you'll find that's the road draft tube, pre-pcv days way to vent the crankcase. Air was taken in through the breather cap on top of the oil fill tube.

I type too slow...

 

It is the crank case vent, before the days of emission control. Helped keep the dust down on those back roads too.

 

8.5 cylinder?? Never heard of such a thing..

Draft tube sounds right, is it supposed to smoke? Its not neccesarily black smoke, just exhaust like smoke. I took it over there this morning because I just finished it and got it running. I am getting backfires upon decerlation, and it sputters on occasion when you hit the gas. I had the timing checked and he had to close the air/fuel mixture screws on the carb because its running very rich... He thinks the carb is too big? Edelbrock 600 cfm..?

 

ok sounds like the draft tube stays.. Any thoughts on the backfiring and sputtering?

 

600 CFM shouldn't be too big

 

Show him the carburetor, I need a laugh.

 

Definately the 8.5, been looking for one for years.



Time for you to learn this stuff yourself. Let the Mechanic work on Priuses, Pri'i?

 

8.5 was a joke. yes it will smoke, more so if your engine is worn.

 

Yep, draft tube and as said, its the crankcase vent prior to PVC. On my 235 it basically emits a vapor.

 

http://www.chevytalk.org/fusionbb/showtopic.php?tid/178987/

http://www.jalopyjournal.com/forum/showthread.php?t=92105

Oh, and get a more knowledgeable mechanic

 

the too much smoke out of the road draft tube can mean its time for a rebuild..a lot of blow by.
a 283 with a 600 Carb on it..yeah that might be a bit too much, if its stock..i wouldnt go much more than 500

Found an old formula for figuring carb size.
CFM = cid x max rpm x volumetric efficent divided by 3456
ie:
283 X 5000 x .75(stock engine) divided 3456 = 307.074
390cfm would be plenty of carb for your 283.

 

Tell the mechanic to look under the distributor cap, there he will find the ***anium flux capacitor, and spring loaded reverberating carbonizer.

 

The backfire is most likely an exhaust leak. Ditch the mechanic......

 

Tman, Im doing my best, this is my first.. I pretty proud to have gotten this far!! I was hoping to get it down to Torque Fest this weekend, but it's just not running as smooth as I would have hoped for this 90 mile trek. Im desperate to get to the revival though..

 

WOW! I cannot believe so much time has p***ed that a real employed mechanic would not recognize what a road draft system is. For the benefit of our younger members, I will explain. Before the days of PVC systems, all engines used a road draft tube to allow fumes and pressure to escape from the inside of the engine. It consisted of two basic parts. The first was a way to let fresh air into the inside of the engine. This was usually done by using an oil filler cap that had a p***age through it with a permanent screened filter system. Some early flatheads had a filtered scoop on the fuel pump stand. The second component is the road draft tube you are refering to. It was a tube (usually about an inch in diameter) that allows fumes etc. to exhaust to the atmosphere. It is usually attach to the intake manifold, and exhausts from the valve chest. (sometimes referred to as the lifter valley). The placement of the tube and it's exhaust end were usually designed to exit in a low pressure area underneath the car, to help pull the fumes, etc. out.

If yours is puffing out that much smoke, you probably have excess blowby, from bad rings, valve seals, etc. You engine will probably need some attention sooner or later.

 

no, only amc's had those factory.

 

, thank goodness you didn't say Rambler, that would really throw that mechanic into a tailspin

 

musicnerd, seriously, if your avatar is your project, very nice- keep up the good work!!! A suggestion would be to hit the flee markets or old book stores, those old giant greasy books that say " MOTORS MANUAL " on them, buy one that hopefully covers your year car. Even if it dont cover your exact year car, learning about points, vacuum gauges, drum brakes, all that is indespensible knowledge. As your learning, modern day mechanics dont have a clue if they cant plug in a diagnostic ****yzer. These books are worth thier weight in Gold to a novice.

 

You've gotten a lot of cute answers, let me offer to help. Yes it's a road draft tube, used to allow crankcase pressure to escape. Otherwise it blows out through the dipstick. The best thing to do is either get the fitting that goes in the road draft hole with a tube for a pcv valve (Positive crankcase ventilation), or drive a freeze plug in the hole, and go pcv through valve cover breathers. You need filtered air in one side and pcv valve out the other into the base of the carburetor. This ****s the oil fumes into the combustion chamber and burns them. And as has been mentioned, if you have that much compression blowing past your rings, it might be time for a set of rings. Hope this helps.

 

If you are getting alot of smoke out of the road draft tube -make sure that the small canister in under the intake manifold-without it you will have issues

 

put a vacuum gauge on it. see if it holds steady vacuum at an idle. might be sticky or carboned up or burnt valve.

 

Hell, it sounds like it's running well enough to get you to Torquefest and back. Once you get there, ask for some help, plenty of folks willing to figure out issues with these old cars.

 

Alright, I'll make a sign that says "NOVICE NEEDS HELP".. haha