Yeah I like use a breather on valve cover on one head and a PCV on the other side hooked up to intake or carb. No major oil leaks. Good stuff. Keep it comin'!
Road Draft Tubes were designed with an angled-cut at the end which would face opposite the air flow while the vehicle was traveling at speed. This angle-cut was supposed to create a vacuum in the crankcase to evacuate the pollutants. It would work while you were running down the highway, but not so when sitting in traffic. Being an old fart, I remember the days when having a worn out engine and sitting in traffic without a/c would result in a passenger compartment full of toxic crankcase fumes. Use a PCV if you can, but make sure to use the correct one because they're calibrated. Also remember that there needs to be a source of filtered air into the opposite end of the crankcase or at the oil filler tube in order for the PCV to work effectively and to promote proper evacuation of crankcase pollutants.
Luckily I missed out on those days of road draft tubes and the passenger compartment being filled with fumes lol. You are correct about using the correct pcv valve for the application and the engine also needs a source of filtered air coming into the engine for a pcv valve to operate correctly.
Some of what you're saying is incomplete and perhaps misleading even if not intentional. The PCV valve doesn't create vacuum. It's basically a pressure relief valve. It operates on differential pressure. Vacuum on one side or pressure on the other can open the valve (usually unseat a ball). A low difference in pressure allows the valve to remain closed. Closed is usually the normal position (not to be confused with fail safe position). Vacuum comes from the intake manifold. Pressure comes from (mainly) blow by gases escaping past rings. A PCV valve doesn't help rings seal. If you have bad rings you have bad rings. The PCV valve system vents the gases back through the intake to be reintroduced into the combustion chamber and prevents excessive pressure in the crankcase. That's what it does. Why reburn and get these oily vapors (sometimes dirty oil) clogging up a throttle body and sludging up valves? Thank the EPA for that.
Technically the vacuum comes from the piston going down in the cylinder drawing the intake charge in. If pcv valve doesn't help ring seal then you need to tell Hastings, Sealed Power, Wiseco and others that recommend that you do have a pcv valve for better piston and ring seal. The big three had already implemented pcv valves before it was mandated by the EPA. California was the only state that required it and that was in 1961. It would be many years later before it became a nationwide mandate by the EPA.
@BlackLabGarage ok technically, is your pvc connected to the intake or the piston? Manufacturers are always ahead of the laws. There's no surprise that tomorrow you need x. You should quote these companies claiming PCV valves help piston rings seal. I wonder which stroke they believe it to be?
High vacuum holds the PCV valve (mostly) closed, otherwise the engine would have difficulty idling. It would be the same as a vacuum leak. Low vacuum allows it to open, in order to pull the blow-by created under load when the throttle is opened. When the throttle is open, the extra air coming from a wide-open PCV valve is only a small percentage of the intake volume so it doesn't dilute the mixture much. If vacuum is opening your PCV valve, you have it installed backwards lol It's not a pressure relief valve, as crankcase pressure would tend to force it closed (the same as vacuum on the intake side). If there was actual pressure in the crankcase, oil and fumes would be blowing out everywhere, including the seals, dipstick tube, and breather cap.
@@captsorghum You have a few things backwards. I said what I said. I never said it was a pressure relief valve. Made sure not to do that. And here you are correcting me on that.
When I started mechanicing the PCV system became mandatory and Hot Rod Magazine always recommended removing the PCV system. They claimed 5 HP gain or something stupid like that. I had one guy bring his nicely done Chevelle in because it kept blowing oil out of gaskets. He removed the system as recommended by Hot Rod in an article with no alternative ventilation. His first lesson in don't believe everything you read or hear.
Yes the pcv valve pulls a vacuum in the crankcase. But it's a major cause of the carbon on the valves and combustion chamber. The best solution is the vacuum pump. The exhaust evacuation system also pulls a vacuum from the crankcase but it's used more on race cars because it not effective at low rpm.
I agree that the vacuum pump is better than a pcv valve. I have used the exhaust evacuation system on a drag car before. I have also seen what happens when they go boom from the check valve not working properly lol
Anyone you have to explain this to is either to old and draft tube Veteran or to young and V-Pump user. Mid 60's-80's or so Folks need to pay attention! They were there for a good for Damn Good reasons!
I agree with you. Unfortunately there are still people who say to just run two breathers and you will be fine. Then they wonder why their new engine blows oil all over the valve covers and has oil leaks
I converted my road draft tube on my 390 to PCV. I basically made my own version of the 64 CA emissions FE PCV setup but way more simplified and probably more effective since I was keeping the baldy valve covers, It works great. I found an old allen head straight thread hydraulic cap that just barely didn't fit in the intake side of where the road draft tube slides into the 90 degree adapter for the intake, filed the threads down until it barely fit in the intake adapter. I drilled the center of the hydraulic cap out so a FV202 PCV valve fit in with some resistance and then used a bit of RTV to seal those threads I filed down seal to the 90 degree elbow, tapped it in the intake and the 3/8 hose goes to the PCV port on the carb. I can still get the PCV valve out if I need to but its a snug fit. Best part is it for the most part looks stock.
I run one but I use a catch can for the oil , Oil especially a 100,000 mile engine it can feed enough oil into the fuel and air vapor to cause detonation. So a little electric motor to make a vacuum and a catch can is better than feeding it in to the intake.
It also cleans your engine. Lot of people "over credit" modern oils for not sludging up your engine, but a lot of that carbon build up was due to improper crank case ventilation. Couple that with the 1st adaptation of the "automatic choke" and it was a recipe for disaster that sent many of these old classics to the Junkyard at 100k miles. Detergent based oils coupled with a good PCV system and you can break the Myth that those old engines had to be rebuilt at 100k miles. Good Stuff as always man!
Yes… but people don’t realize it doesn’t have to go back into the motor… I saw junkyard digs drove a car to Dalton’s house with horrible blow by and just used the pcv to make an oreillys 1 gallon oil bottle catch can for the oil and just kept pouring it back in every 30 minutes when it would run out of oil lol
well not really, I have a 2018 boat with a volvo v8 (ls 5.3 basically) and there is no pcv like a car going into any of the intake. What they do is they run a hose from each valve cover to the front of the air filter (flame arrestor). IF the PCV system was really designed to be advantageous, boats would have it. EPA is the reason behind PCV, 100% and since boat have different EPA regs, they don't have one -yet-.
Some Volvo (GM) engines the pcv valve is actually in the hose. But regardless even if yours does not have it in the hose, by running the hose to the air filter housing it is still pulling vacuum on the crankcase just like a conventional pcv system does.
@@BlackLabGarage I think he means the hose runs to the intake upstream of the carb or throttle body. So there is no real vacuum, therefore no need for a PCV valve to limit flow at idle. I imagine the air draft and/or slight vacuum inside the air filter (if the outlet is inside the filter) draws crankcase fumes in the same way as a draft tube. Maybe they can get away with it because it's on a boat that doesn't have to idle in traffic or meet EPA regs. Seems like it would tend to gunk up a carb or throttle body though.
@@captsorghum yeah I know what he meant but from what I looked up there is still a vacuum pull on the hose. Maybe not as much as hooking it straight to the intake manifold but it says there is still vacuum there. Which makes sense because air flowing by the opening of the hose would indeed have that effect on the hose
The problem here is not the PCV valve system... But the people who have forgotten their 8th grade science... Vaccum is a great thing even better if you know how to use it.. And understand how it realates to pressure... I've had mod ford engines come in with the vac hoses screwed up blowing valve cover gaskets... And people saying how can it build pressure if its all sealed up! 😂😂😂... They just can't grap the concept!
Thank you! I wonder why my motorcycles don’t use a pcv system tho, especially my dirt bikes which are relatively new just vent to atmosphere.. also I used a valley pan per your recommendation on my 85’ 370 but just to clarify you said if you block the egr port at the head you can go without the valley pan? Thanks!
The pcv system is better than nothing but it also causes problems such as carbon buildup and clogging millions of catalytic converters. The pcv system alone is not good enough and needs to be used with a catch can or similar device to catch all that crap instead of putting it back into the engine.
Yeah I like use a breather on valve cover on one head and a PCV on the other side hooked up to intake or carb. No major oil leaks. Good stuff. Keep it comin'!
That’s the way it should be done. Clean filtered air coming in as the pcv system pulls the stuff out. Thank you for your kind words
Road Draft Tubes were designed with an angled-cut at the end which would face opposite the air flow while the vehicle was traveling at speed. This angle-cut was supposed to create a vacuum in the crankcase to evacuate the pollutants. It would work while you were running down the highway, but not so when sitting in traffic. Being an old fart, I remember the days when having a worn out engine and sitting in traffic without a/c would result in a passenger compartment full of toxic crankcase fumes.
Use a PCV if you can, but make sure to use the correct one because they're calibrated. Also remember that there needs to be a source of filtered air into the opposite end of the crankcase or at the oil filler tube in order for the PCV to work effectively and to promote proper evacuation of crankcase pollutants.
Luckily I missed out on those days of road draft tubes and the passenger compartment being filled with fumes lol. You are correct about using the correct pcv valve for the application and the engine also needs a source of filtered air coming into the engine for a pcv valve to operate correctly.
Some of what you're saying is incomplete and perhaps misleading even if not intentional.
The PCV valve doesn't create vacuum. It's basically a pressure relief valve. It operates on differential pressure. Vacuum on one side or pressure on the other can open the valve (usually unseat a ball). A low difference in pressure allows the valve to remain closed. Closed is usually the normal position (not to be confused with fail safe position).
Vacuum comes from the intake manifold. Pressure comes from (mainly) blow by gases escaping past rings.
A PCV valve doesn't help rings seal. If you have bad rings you have bad rings.
The PCV valve system vents the gases back through the intake to be reintroduced into the combustion chamber and prevents excessive pressure in the crankcase.
That's what it does.
Why reburn and get these oily vapors (sometimes dirty oil) clogging up a throttle body and sludging up valves? Thank the EPA for that.
Technically the vacuum comes from the piston going down in the cylinder drawing the intake charge in. If pcv valve doesn't help ring seal then you need to tell Hastings, Sealed Power, Wiseco and others that recommend that you do have a pcv valve for better piston and ring seal. The big three had already implemented pcv valves before it was mandated by the EPA. California was the only state that required it and that was in 1961. It would be many years later before it became a nationwide mandate by the EPA.
@BlackLabGarage ok technically, is your pvc connected to the intake or the piston?
Manufacturers are always ahead of the laws. There's no surprise that tomorrow you need x.
You should quote these companies claiming PCV valves help piston rings seal. I wonder which stroke they believe it to be?
High vacuum holds the PCV valve (mostly) closed, otherwise the engine would have difficulty idling. It would be the same as a vacuum leak. Low vacuum allows it to open, in order to pull the blow-by created under load when the throttle is opened. When the throttle is open, the extra air coming from a wide-open PCV valve is only a small percentage of the intake volume so it doesn't dilute the mixture much. If vacuum is opening your PCV valve, you have it installed backwards lol
It's not a pressure relief valve, as crankcase pressure would tend to force it closed (the same as vacuum on the intake side). If there was actual pressure in the crankcase, oil and fumes would be blowing out everywhere, including the seals, dipstick tube, and breather cap.
@@captsorghum without one there is definitely crankcase pressure
@@captsorghum You have a few things backwards. I said what I said. I never said it was a pressure relief valve. Made sure not to do that. And here you are correcting me on that.
When I started mechanicing the PCV system became mandatory and Hot Rod Magazine always recommended removing the PCV system. They claimed 5 HP gain or something stupid like that. I had one guy bring his nicely done Chevelle in because it kept blowing oil out of gaskets. He removed the system as recommended by Hot Rod in an article with no alternative ventilation. His first lesson in don't believe everything you read or hear.
Yeah take anything Hot Rod says with a grain of salt lol
Yes the pcv valve pulls a vacuum in the crankcase. But it's a major cause of the carbon on the valves and combustion chamber. The best solution is the vacuum pump. The exhaust evacuation system also pulls a vacuum from the crankcase but it's used more on race cars because it not effective at low rpm.
I agree that the vacuum pump is better than a pcv valve. I have used the exhaust evacuation system on a drag car before. I have also seen what happens when they go boom from the check valve not working properly lol
That’s why use moroso exhaust one way valves like drag cars and let the after burner deal with the vapor.
@@RobertYonng I've used those on drag cars but I never have used them on a street car
@@BlackLabGarage It would be illegal on a street car, at least in a state with pollution laws.
@@captsorghum yeah we don’t even have yearly inspections here
Good asvice. Thanks
You're welcome!
Anyone you have to explain this to is either to old and draft tube Veteran or to young and V-Pump user. Mid 60's-80's or so Folks need to pay attention! They were there for a good for Damn
Good reasons!
I agree with you. Unfortunately there are still people who say to just run two breathers and you will be fine. Then they wonder why their new engine blows oil all over the valve covers and has oil leaks
I converted my road draft tube on my 390 to PCV. I basically made my own version of the 64 CA emissions FE PCV setup but way more simplified and probably more effective since I was keeping the baldy valve covers, It works great. I found an old allen head straight thread hydraulic cap that just barely didn't fit in the intake side of where the road draft tube slides into the 90 degree adapter for the intake, filed the threads down until it barely fit in the intake adapter. I drilled the center of the hydraulic cap out so a FV202 PCV valve fit in with some resistance and then used a bit of RTV to seal those threads I filed down seal to the 90 degree elbow, tapped it in the intake and the 3/8 hose goes to the PCV port on the carb. I can still get the PCV valve out if I need to but its a snug fit. Best part is it for the most part looks stock.
That sounds like a good set up
I run one but I use a catch can for the oil , Oil especially a 100,000 mile engine it can feed enough oil into the fuel and air vapor to cause detonation. So a little electric motor to make a vacuum and a catch can is better than feeding it in to the intake.
I agree with that on high mileage engines.
It also cleans your engine. Lot of people "over credit" modern oils for not sludging up your engine, but a lot of that carbon build up was due to improper crank case ventilation.
Couple that with the 1st adaptation of the "automatic choke" and it was a recipe for disaster that sent many of these old classics to the Junkyard at 100k miles. Detergent based oils coupled with a good PCV system and you can break the Myth that those old engines had to be rebuilt at 100k miles.
Good Stuff as always man!
I agree with you as always! Thank you for your kind words!
Yes… but people don’t realize it doesn’t have to go back into the motor…
I saw junkyard digs drove a car to Dalton’s house with horrible blow by and just used the pcv to make an oreillys 1 gallon oil bottle catch can for the oil and just kept pouring it back in every 30 minutes when it would run out of oil lol
Very true. A catch can is fine to use. I seen that episode and all I can say is they had way more patience than I would have😂
But wait...the PCV valve helps ring seal
At least, I've been told
well not really, I have a 2018 boat with a volvo v8 (ls 5.3 basically) and there is no pcv like a car going into any of the intake. What they do is they run a hose from each valve cover to the front of the air filter (flame arrestor). IF the PCV system was really designed to be advantageous, boats would have it. EPA is the reason behind PCV, 100% and since boat have different EPA regs, they don't have one -yet-.
Some Volvo (GM) engines the pcv valve is actually in the hose. But regardless even if yours does not have it in the hose, by running the hose to the air filter housing it is still pulling vacuum on the crankcase just like a conventional pcv system does.
@@BlackLabGarage I think he means the hose runs to the intake upstream of the carb or throttle body. So there is no real vacuum, therefore no need for a PCV valve to limit flow at idle. I imagine the air draft and/or slight vacuum inside the air filter (if the outlet is inside the filter) draws crankcase fumes in the same way as a draft tube. Maybe they can get away with it because it's on a boat that doesn't have to idle in traffic or meet EPA regs. Seems like it would tend to gunk up a carb or throttle body though.
@@captsorghum yeah I know what he meant but from what I looked up there is still a vacuum pull on the hose. Maybe not as much as hooking it straight to the intake manifold but it says there is still vacuum there. Which makes sense because air flowing by the opening of the hose would indeed have that effect on the hose
The problem here is not the PCV valve system... But the people who have forgotten their 8th grade science... Vaccum is a great thing even better if you know how to use it.. And understand how it realates to pressure... I've had mod ford engines come in with the vac hoses screwed up blowing valve cover gaskets... And people saying how can it build pressure if its all sealed up! 😂😂😂... They just can't grap the concept!
So......is there really a pcv controversy?
There sure is because there are still people that argue that a pcv or vacuum pump is not needed
Thank you! I wonder why my motorcycles don’t use a pcv system tho, especially my dirt bikes which are relatively new just vent to atmosphere.. also I used a valley pan per your recommendation on my 85’ 370 but just to clarify you said if you block the egr port at the head you can go without the valley pan? Thanks!
You can block the exhaust crossover at the head or in the intake just as long as it’s blocked off to keep from heating that passage in the intake up
The pcv system is better than nothing but it also causes problems such as carbon buildup and clogging millions of catalytic converters.
The pcv system alone is not good enough and needs to be used with a catch can or similar device to catch all that crap instead of putting it back into the engine.
Especially in the case of high mileage engines