Road Draft Tube VS PCV - The 1947 - Present Chevrolet & GMC Truck Message Board Network

skokie · 12-28-2004, 07:32 PM

What are the pros and cons of a road draft tube in the back of the block vs a pcv in one of the valve covers or in the oil filler tube?

Thanks

crazy longhorn · 12-28-2004, 07:53 PM

Road draft.....yea, i remember seeing that so called set up......If I remember right, 61 or 62 was the last of that! there is a good advantage running a PCV system.....keep that oil in the eng! some veiw the pcv system as "early emissions controls".....maybe so, but I feel that the pcv does a lot for the rings(keepin things sealed).....crazyL

Tx Firefighter · 12-28-2004, 08:10 PM

PCV is all I would use.

You want those nasty fumes out of the engine. A road draft tube was marginal at best. The PCV will keep the crankcase cleaner, the oil will last longer, and the engine won't sludge up near as bad.

Your 68 would have had a PCV here in Texas brand new, so I'd definitely assume that your California truck definitely had one stock.

skokie · 12-28-2004, 08:46 PM

Tx Firefighter
When I got the truck it had the scripted valve covers on it with a pvc in the oil filler tube going to the carb. No breather that I could locate. I like the look of the scripted valve covers but I dont want to mess up the engine. Any thoughts on how I could do this?

JimKshortstep4x4 · 12-28-2004, 08:53 PM

One of my friends has a 67 Impala with the scripted valve covers. He had his block drilled and tapped for a 90 degree 3/8 fitting with the pcv in the hose.
The hose is connected to the carb in back so it is pretty well out of sight. The oil filler tube has a filter cap on it to complete the circuit.

Jim

mr402 · 12-28-2004, 09:07 PM

Need to check with some of the car guys but if I recall correctly there is a fitting that goes in the place of the draft tube onthe back of the intake to install a PCV. Saw a 409 set up this way. If they can do it with a 409 I'm certain they can do it with a small block. I agree with the rest run the PCV.

skokie · 12-29-2004, 12:09 AM

Quote:

Originally Posted by Tx Firefighter

PCV is all I would use.

You want those nasty fumes out of the engine. A road draft tube was marginal at best. The PCV will keep the crankcase cleaner, the oil will last longer, and the engine won't sludge up near as bad.

Your 68 would have had a PCV here in Texas brand new, so I'd definitely assume that your California truck definitely had one stock.

Do you mean a pcv in the valve cover or is there a way to run one where the road draft tube would go?

jimfulco · 12-29-2004, 02:16 AM

Here's the PCV adapter that goes where the draft tube was.

About the only good thing about having a draft tube is that you can make the engine idle very slowly.

skokie · 12-29-2004, 03:34 AM

So I can convert it from the road draft tube to the pcv. Hmm ok thats intersting. So it wont matter what year 327 I get.
Thanks for all of the info.

Fred T · 12-29-2004, 07:39 AM

Quote:

Originally Posted by skokie

So I can convert it from the road draft tube to the pcv. Hmm ok thats intersting. So it wont matter what year 327 I get.
Thanks for all of the info.

All you have to do to the tube is plug the vent and drill a hole for a grommet and pcv valve. If you want to get fancy cut the vent tube off the side and weld in a curved plug.

olblue60@aol.com · 12-29-2004, 10:04 AM

I have the road draft tube on my 60 sedan delivery. You will need to have a black driveway because they tend to drip an ocasional drop of oil. I believe thats why the change was made.

John

12-28-2004, 07:32 PM	#1
skokie Registered User Join Date: Oct 2003 Location: San Jose Ca. Posts: 3,334	Road Draft Tube VS PCV What are the pros and cons of a road draft tube in the back of the block vs a pcv in one of the valve covers or in the oil filler tube? Thanks __________________ RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234

12-28-2004, 07:53 PM	#2
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,403	Road draft.....yea, i remember seeing that so called set up......If I remember right, 61 or 62 was the last of that! there is a good advantage running a PCV system.....keep that oil in the eng! some veiw the pcv system as "early emissions controls".....maybe so, but I feel that the pcv does a lot for the rings(keepin things sealed).....crazyL __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

12-28-2004, 08:10 PM	#3
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	PCV is all I would use. You want those nasty fumes out of the engine. A road draft tube was marginal at best. The PCV will keep the crankcase cleaner, the oil will last longer, and the engine won't sludge up near as bad. Your 68 would have had a PCV here in Texas brand new, so I'd definitely assume that your California truck definitely had one stock. __________________ I'm on the Instagram- @Gearhead_Kevin

12-28-2004, 08:46 PM	#4
skokie Registered User Join Date: Oct 2003 Location: San Jose Ca. Posts: 3,334	Tx Firefighter When I got the truck it had the scripted valve covers on it with a pvc in the oil filler tube going to the carb. No breather that I could locate. I like the look of the scripted valve covers but I dont want to mess up the engine. Any thoughts on how I could do this? __________________ RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234

12-29-2004, 03:34 AM	#9
skokie Registered User Join Date: Oct 2003 Location: San Jose Ca. Posts: 3,334	So I can convert it from the road draft tube to the pcv. Hmm ok thats intersting. So it wont matter what year 327 I get. Thanks for all of the info. __________________ RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234

12-28-2004, 08:53 PM	#5
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	One of my friends has a 67 Impala with the scripted valve covers. He had his block drilled and tapped for a 90 degree 3/8 fitting with the pcv in the hose. The hose is connected to the carb in back so it is pretty well out of sight. The oil filler tube has a filter cap on it to complete the circuit. Jim

12-28-2004, 09:07 PM	#6
mr402 Registered User Join Date: Jan 2004 Location: Elmira, Oregon Posts: 449	Need to check with some of the car guys but if I recall correctly there is a fitting that goes in the place of the draft tube onthe back of the intake to install a PCV. Saw a 409 set up this way. If they can do it with a 409 I'm certain they can do it with a small block. I agree with the rest run the PCV.

12-29-2004, 02:16 AM	#8
jimfulco Registered User Join Date: May 2003 Location: Shreveport LA Posts: 3,170	Here's the PCV adapter that goes where the draft tube was. About the only good thing about having a draft tube is that you can make the engine idle very slowly.

12-29-2004, 10:04 AM	#11
olblue60@aol.com member Join Date: Dec 2003 Location: Silver Spring Md.20901 Posts: 2,031	I have the road draft tube on my 60 sedan delivery. You will need to have a black driveway because they tend to drip an ocasional drop of oil. I believe thats why the change was made. John __________________ 1967 C/K10 Chevy Panel 1968 C/K20 Chevy Pickup 1968 C/K10 Chevy Suburban 1941 Chevy Sedan Delivery 1960 Chevy Sedan Delivery 1972 Camaro SS 396 #s matching 1971 Harley FX Superglide



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