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Discussion Starter #22 (Edited)
Like the old,old, saying" If it ain't broke, don't fix it".


But, this was suppose to be "routine" maintenance.

Gonna leave well enough alone, it's running like a top.


Except, ever since I've had this vehicle, when I put in park there seems an awful lot of "slack" in the parking pawls....if parking pawls is correct.


Took it to the dealer, said; "Nothing wrong, thats the way it is".
 

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At some point in the early 60's GM switched most V8's from a road draft setup to the PCV setup. On my '61 Impala I just stuck breathers in each valve cover and it would idle so poorly and have no power off idle, after doing research I decided to put the PCV back on and it fixed all of the problems I was having. I'm a firm believer that all engines should have a PCV setup, I will be adding one to my 348 W motor's valve cover when I rebuild it.

I wish mine card still had the road draft tube and no emissions crap, no fuss, no muss, no exhaust gas introduced into the induction system. And a 1" steel pipe can relieve crankcase pressure faster than a rubber hose connected to a spring loaded valve. If we're talking stock setup, the early 60s 283/348s and 194s had road draft tubes and the carbs were not setup with a vacuum takeoff for a reason, engine was designed to run on straight gas/air and not to suck oily crankcase gases especially when the chokeplate is closed in cold weather. System required only a periodic cleaning of the reusable valve cover breather. These engines cannot run correctly with a breather in each valve cover, the blowby gases will choke and dilute the mixture in the combustion chambers.....no vacuum source and pressure across both breathers so the gases cannot escape the crankcase effectively. Road draft tubes work on a venturi principle where air moving under the car across the end of the tube creates a partial vacuum so fresh air enters the breather and crankcase gases get sucked out the end of the road draft tube. My 194 was a smoker, never saw the blowby gas when moving, but when stopped for a light the smoke from the tube came out of the passenger wheel well, more than one date and adjacent cars had remarked the car was on fire.


For my 2 cents the road draft tube meets 60's emissions so why not reinstall it and run only on gas and air, and not burned crap.....might even increase gas mileage.
 

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I wish mine card still had the road draft tube and no emissions crap, no fuss, no muss, no exhaust gas introduced into the induction system. And a 1" steel pipe can relieve crankcase pressure faster than a rubber hose connected to a spring loaded valve. If we're talking stock setup, the early 60s 283/348s and 194s had road draft tubes and the carbs were not setup with a vacuum takeoff for a reason, engine was designed to run on straight gas/air and not to suck oily crankcase gases especially when the chokeplate is closed in cold weather. System required only a periodic cleaning of the reusable valve cover breather. These engines cannot run correctly with a breather in each valve cover, the blowby gases will choke and dilute the mixture in the combustion chambers.....no vacuum source and pressure across both breathers so the gases cannot escape the crankcase effectively. Road draft tubes work on a venturi principle where air moving under the car across the end of the tube creates a partial vacuum so fresh air enters the breather and crankcase gases get sucked out the end of the road draft tube. My 194 was a smoker, never saw the blowby gas when moving, but when stopped for a light the smoke from the tube came out of the passenger wheel well, more than one date and adjacent cars had remarked the car was on fire.


For my 2 cents the road draft tube meets 60's emissions so why not reinstall it and run only on gas and air, and not burned crap.....might even increase gas mileage.
You touched on what I understand to be the negatives... the venturi effect means road draft tubes are ineffective while stopped and at low speeds. There's also the issue of it not actually being an emissions system, it just dumps the excess pressure and whatever is suspended in the air into the atmosphere...

I considered going back to a road draft setup on the 348 (it has most of the parts) but my 283 is from '67 so it doesn't have the parts and I don't see the benefit in buying them for it. To be honest, while I'm not a tree hugger or any of that I don't have much of an issue with running a PCV valve setup, I've had the intake manifold off after a couple years of driving and the valves don't have excessive buildup. The spark plugs also show little sign of oil burning. I can do this small thing for the environment.
 

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A properly functioning pcv system is a good thing for the engine regardless of the emissions component. You remove corrosive byproducts from the oil to keep it cleaner, reduce windage in the crankcase (which improves power), and also improve seal life by not pressurizing the crankcase and causing oil leaks. There's a reason racer cars will run a vacuum pump, to keep the crankcase at negative pressure (you will actually gain ~10hp or so at ~500hp via reduced windage, obviously gains can increase with higher hp and higher RPM setups).

You can't just vent a crankcase to atmosphere on an EFI car with a MAF as it will allow unmetered air into the engine and throw off the tune.


So no, a road draft tube from the dark ages isn't the superior solution just as a carb isn't...
 

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there was a post a while back- on how long the car could move/roll, before the transmission pawl would engage....
 

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Agreed, a properly functioning PCV system is a good thing because it removes corrosive by products of combustion......but what does it do with them?.....it stuffs them right back into the engine where it can crap up the induction system. Sort of like washing the car and dumping the bucket of dirty soap water into the washing machine instead of onto the driveway.



A vacuum pump to keep negative pressure in the crankcase is an excellent idea, but importantly what does it do with the corrosive crap coming out of the exhaust side of the vacuum pump? Because if it throws it back into the induction system it negates the idea of increased vacuum in the crankcase. If it dumps it into the atmosphere, which makes more sense, it is in reality acting on the same principle of a motorized road draft tube, albeit more efficient.


Doesn't seem to make any sense to run a racing engine with a PCV system or an EGR for that matter.
 

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Discussion Starter #28
Haven't measured the roll, but it seems around a 10 to 12 in. Which, seems excessive to me. But the young service man at Jerry's Chevy dealership said it was normal.


Will do a little research.
 

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I beleive thats what others said- up to a foot--- which seemed excessive.
But I think mine may be a couple of inches.
 

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Haven't measured the roll, but it seems around a 10 to 12 in. Which, seems excessive to me. But the young service man at Jerry's Chevy dealership said it was normal.


Will do a little research.
I think I'd soil myself if my car rolled a foot after engaging park... My '14 only rolls a couple inches which seems normal to me based on the cars in my signature. If it rolled a foot I'd definitely bump a car in the parking lot.
 

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Agreed, a properly functioning PCV system is a good thing because it removes corrosive by products of combustion......but what does it do with them?.....it stuffs them right back into the engine where it can crap up the induction system. Sort of like washing the car and dumping the bucket of dirty soap water into the washing machine instead of onto the driveway.



A vacuum pump to keep negative pressure in the crankcase is an excellent idea, but importantly what does it do with the corrosive crap coming out of the exhaust side of the vacuum pump? Because if it throws it back into the induction system it negates the idea of increased vacuum in the crankcase. If it dumps it into the atmosphere, which makes more sense, it is in reality acting on the same principle of a motorized road draft tube, albeit more efficient.


Doesn't seem to make any sense to run a racing engine with a PCV system or an EGR for that matter.
A poorly designed PCV system doesn't render all PCV systems a bad idea. An ideal setup will allow oil mist to separate out and just carry the vapors, thus minimizing oil collection in the intake tract. Putting it back into the intake is a necessity since you need the vacuum source in the first place, and the fact you can combust the nasties instead of breathing them in is a nice side benefit. The PCV isn't the only source of oil in the intake - depending on ring condition and reversion between the cylinders, you'll often see some oil build up just from blowby - I've seen the top ends of race setups that ditched the PCV and just ran a breather and you still get dirty intake ports.

A vacuum pump will discharge into an accumulator can, basically a better version of a simple catch can since the pump will pull out a lot more blowby, particularly since if you're building an engine with the intent to run a vacuum pump you'll usually use lower tension rings to free up power and let the pump provide the sealing. Then the can is usually vented out through a filter to atmosphere out of simplicity.

EGR is pretty much a thing of the past since variable cam timing can add or remove overlap as needed to perform the same NOx reduction. The Traverse doesn't have an EGR. Even my non VVT LS1 and LS3 have never had an EGR.
 

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Discussion Starter #32
Ok, in the left picture the new pcv valve is in the hose and zip tide to another hose running along side it.


The plan is to get a short piece of hose,remove the screw, clamp it to the old piece of "valve" sticking out of the manifold and clamp the other end to the new valve.


Should put it back to functioning as originally intended.


Right now the vehicle is running good, but the valve is not recycling the bad stuff.
 

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Discussion Starter #33
Got a 1 &1/4 in. piece of 1/2 in. emission hose, clamped it to the new pcv valve,removed the screw and clamped that to the piece of valve(see picture somewhere above), and cranked it up.



Runs like a new one and should be recycling the bad stuff as intended.



One last thing..........that's a machined hole in the cover, with a "pcv valve" in it. Correct me if I'm wrong but "logic" tells me that the valve should be replaced or at least cleaned from time to time.



As stated before on this forum, and I've checked, GM does not even list a pcv valve part for this vehicle, but, O'Reilley's does.



Go figure.
 

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Is this "PVC" valve in the pics open inside? I seen a video where they drilled out the holes a little for better flow. I pulled mine this past weekend and it was all gummed up. I cleaned her up and opened up the holes on both ends.
 

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Is this "PVC" valve in the pics open inside? I seen a video where they drilled out the holes a little for better flow. I pulled mine this past weekend and it was all gummed up. I cleaned her up and opened up the holes on both ends.
Yea it's not an actual PCV valve like we are used to, it's really just controlling flow through the orifice, enlarging them slows down the gas which helps the suspended solids settle out rather than get sucked into the manifold.
 

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Been all over the net, U tube, etc.


Nobody has had a seized valve..............Why Me??


Answer............Why Knot.


But, that thing is coming outta there even if I gotta put a torch on it........and I gotta half a mind to do it.


The BW...IE: Beautiful Wife agrees.........I gotta half a mind.
Have the same problem this is the worst ever vehicle gm has ever produced.
 

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Well I don't know about that. Remember the Vega? Yes this vehicle has it issues but it is far from being the worst. I am on my second Lambda. First a 08 Outlook, WavePlate, P.S. Pump and Rack, waterpump, Plugs at the first 100K, A couple of Purge Valves, 2 sets of Tires, Stabilitrack, Milkshakes, Throttle Body clogged PCV, MAF sensors, 212K I can't reall complain too much. I now have a Certified 2015 Enclave,60K no problems so far.
 

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The best solution is the 1 way vented cfm oil cap
Any pressure in crankcase , which comes from piston blow by , will blow out oil cap
If intake manifold is in vacuum state, and if it sucks air in through the dirty side PCV orifice. Then cfm oil cap will seal shut, and will not throw off fuel trims by allowing UN metered air into crankcase
Since crankcase no longer has positive pressure from piston blow by ... because of cfm oil vap
No crankcase gunk will be pushe out of crankcase via clean side PCV breather hose and into clean air air intake hose ( between air filter and throttle body)
Since crankcase sees zero psi pressure, it does not "pressure cook" the crankcase fumes and deposit them as "varnish" all over the inside of your crankcase.
Thus making your engine last longer.
My 2 cents ^^
 

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Discussion Starter #39
Well I don't know about that. Remember the Vega? Yes this vehicle has it issues but it is far from being the worst. I am on my second Lambda. First a 08 Outlook, WavePlate, P.S. Pump and Rack, waterpump, Plugs at the first 100K, A couple of Purge Valves, 2 sets of Tires, Stabilitrack, Milkshakes, Throttle Body clogged PCV, MAF sensors, 212K I can't reall complain too much. I now have a Certified 2015 Enclave,60K no problems so far.
How bout the "Unsafe at Any Speed"......IE: Corvair?
 

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How bout the "Unsafe at Any Speed"......IE: Corvair?
The '60-'63 Corvair certainly had a problem with the swing axle design that pivoted at the transaxle and could, under certain conditions, cause the axle to "tuck". Ralph Nader's book, unfortunately, painted the '64 and later Corvair's with the same brush. However, the modified design that incorporated universal joints at the out-board end of the axle shaft enable the wheel to remain in a vertical alignment even when the suspension was compressing or rebounding. It was a design very similar to the independent suspension incorporated in the '63 Corvette--but you never hear of them having a safety issue due to rear suspension design. Just my opinion, but I think the '64 and later Corvairs were an excellent car--especially the Corsa with the turbo. Fun cars to drive!
 
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