Engine: Road draft tube vs. PCV system

[SuperHawk]

My son and myself are restoring a 1960 Hawk, 289, 3 speed overdrive. Engine has been rebuilt, basically to stock. We would like to know if the PCV system is much better to implement on this engine than was the road draft tube affair it originally came with. I can go either way, as I have necessary parts in stock to do either. I just do not know if one system is better than the other ....

Carburetor likely will be an Edelbrock 1403 (500 cfm).

If we do end up going with a Studebaker style PCV system, will I need to discard the 1960 rocker arm covers and use the later model type with the breather caps, or will the stock breather cap on the oil filler tube be adequate?

I welcome your advice on which way to proceed.

Larry

[PackardV8]

Absolutely, positively, a good PCV system keeps the inside of the engine cleaner. I've torn down hundreds of engines and those with the best PCV systems are the cleanest. Suggest fabbing up the complete system which has a hose from the breather cap drawing air from inside the air filter.

OT, but for whatever reason some of the AMC engines have a small diameter PCV hose and they are always sludged up.

jack vines

[Mike Van Veghten]

Just remember, to work properly, it "must" be a closed system. That is no outside air can enter the system.
All this also presumes that the ring end gaps were set properly, ie., very low blowby....or ring leakage.

Mike

[JoeHall]

Just remember, to work properly, it "must" be a closed system. That is no outside air can enter the system.
All this also presumes that the ring end gaps were set properly, ie., very low blowby....or ring leakage.

Mike

Perhaps California mandates a closed system (whatever that is), but the Stude was designed as a ventilating system, with "outside" air coming in somewhere, picking up vapors & contaminants (mostly from blowby), then exiting somewhere else. The entrance is through the breather cap(s), and the exit is through the road draft tube or the PCV. The PCV is environmentally friendlier, since it passes the vapors into the intake & combustion chamber, where they are burned.
Fox max effectiveness of a PCV system, a breather cap on each valve cover would be preferable to just the one on the front of the engine. "Breather" cap, means it breathes outside air into the engine, whether it is an early engine with road draft tube, or later with PCV.

[PackardV8]

Yes, any PCV system has to have make-up air intake. What MVV probably meant was the only air being drawn in should come from inside the air cleaner.

No, Stude's system was first generation and didn't filter intake air other than the mesh in the breather cap. The second generation systems from other manufacturers had the oil filler cap sealed and getting it's intake air through a hose going into the bottom of the air filter. Thus, air being pulled in through the "breather" cap was being filtered by the air filter. Much better than having dusty outside air being sucked into the interior of the engine.

jack vines

[Mike Van Veghten]

Yea..sorry, Jack is correct.
Any air going into the crankcase is filtered first.
This in turn...makes it a closed system.

Mike

[StudeRich]

Yea..sorry, Jack is correct.
Any air going into the crankcase is filtered first.
This in turn...makes it a closed system.Mike

The interesting thing about late model Stude./GM V8 Engines is that Studebaker finally DID start using closed Systems like Jack and Mike are talking about Studes. NOT having!

The Canadian imported to Calif. and possibly all States late 1964 Models did have a sealed Oil Cap on the drivers side, a hose fitting equipped Cap on the Pass. side, a hose from it to the Air Cleaner, however I am having a hard time remembering if Dad's '64 had it on the OUTSIDE of the Air cleaner Case or on the bottom where the cleaned air is.
If I remember right it was on the Outside, maybe because there was no small special filter for the crankcase oil/dirt as on newer cars, so this air which is only drawn through the Carb. at higher speed, was filtered by the same Element as the Carb. Air.

And then there was the '63 version PCV Valve & hose system for low speed, low vacuum on late '64's as well coming out of the Valve Lifter Cover.
The '65 and '66 Models also have a sealed system, at least all of the West Coast Cars I've seen and probably ALL.

[wittsend]

I have, by the VIN, a Canadian built, '64 Daytona (all be it with Commander trim). The Studebaker engine was swapped with a 283 Chevy, but the "Made in Canada" casting numbers prove it a McKinnon. So, this must have been a '65 or '66 engine. While it had a PCV it was not what I'd define as a closed system. The air entered the engine through the mesh packed, oil cap/dipstick. I have no idea when this car was brought to the west coast. There was a lot of Canadian coinage, beer cartons insurance and auto club items found in the car. I doubt it was intended for original sale here.

So, maybe there was a mandate for a closed system for cars shipped to California for original sale??? Yet my memory recollects that '66 was the year California made that an issue. The old smog laws required testing for only '66 and newer cars. I know this law well. I had a leftover (last year - 1965) Volvo 544. Because the car lingered into the '66 model year the intended '65 car was required to be smogged. This shrunk down version of a late 40's Ford had to be the oldest looking car to ever be required a smog test in California.

Tom

[JoeHall]

Yes, any PCV system has to have make-up air intake. What MVV probably meant was the only air being drawn in should come from inside the air cleaner.

No, Stude's system was first generation and didn't filter intake air other than the mesh in the breather cap. The second generation systems from other manufacturers had the oil filler cap sealed and getting it's intake air through a hose going into the bottom of the air filter. Thus, air being pulled in through the "breather" cap was being filtered by the air filter. Much better than having dusty outside air being sucked into the interior of the engine.

jack vines

I recall the mid 1980s, when a smog inspector in SoCal tried to make me hook up the 56J similar to what you describe, in order to pass inspection and register the car. I do nto not recall mention of a PCV, but he wanted a sealed cap, with connector hose going to the air cleaner. I had began with the set up, to include drilled a hole in the air cleaner, when someone told me about C.A.R.B. I went through whatever wickets I was advised in contacting them, and they sent me a window sticker that said something to the effect of "CARB waived". With that, DMV registered the car without a smog certification, and I never encountered that problem again during the remaining 10 years or so that I lived in SoCal.

[speedbump]

The other part of "closed system" is under periods of low manifold vacuum, like acceleration, when the PCV isn't working very well, the HC's of blowby have an alternate path to the air cleaner where they can be burned in the intake charge. That way, no matter which path, no HC's are released to the atmosphere......thus "closed".

[Dan Timberlake]

The attachment is a page in the 1951 Chevy manual supplement section that describes a PCV (positive crankcase ventilation valve) as standard equipment on their big trucks, and a recommended option to be installed on vehicles in low speed, stop and go service that might be "conducive to sludging of the engine". I included that to keep PCV valves from being incorrectly lumped into the category of strictly "emissions" equipment.

here is a link to an image showing open and closed systems. Make and model unknown.

http://constructionmanuals.tpub.com/14264/img/14264_152_3.jpg

here is a link to an image of an air cleaner with a batch of emissions related hardware tucked inside, but all on the unfiltered side of the airfilter element.

http://home.sprynet.com/~dale02/aircl.jpg

Item 2 is a small chunk of foam covering the tube that is the start of the PCV system.

Some PCV filters are more elaborate.

http://t0.gstatic.com/images?q=tbn:ANd9GcRMukpBufhvzMv1JS7I4AphDSCZg3srSDDKqRQrNNuPLpKAPheu

[swvalcon]

If this is a car that will see very little mileage with regular oil changes I would just put it back stock. You wont drive it enough to hurt the air and oil should stay clean with regular changes.