Turbo - PCV Side Effects?
- Thread starter powerband
- Start date
I use a PCV in my setup and kept the factory oil fill cap/breather in the valve cover for fresh air. I had problems with the cheap auto zone PCV valves however as they would not fully seal under boost and would pressurize the crankcase and then kindly blow the dipstick out making a huge mess for me to clean. I installed a high quality PCV valve from the Ford dealer that actually closes under boost. The application was for a turbo tbird and it was a very well spent 10 dollars. 
The only mod for me was stuffing some scothcbrite into the factory valve cover breather to create a restriction and to filter the fresh air.
Plenty of people will tell you not to use a PCV with a turbo system, but plenty of people will also tell you that Elvis Presley is alive and well. Grain of salt, man. Grain of salt. 8)
The only mod for me was stuffing some scothcbrite into the factory valve cover breather to create a restriction and to filter the fresh air.
Plenty of people will tell you not to use a PCV with a turbo system, but plenty of people will also tell you that Elvis Presley is alive and well. Grain of salt, man. Grain of salt. 8)
When I started building turbo cars I didn't use a PCV valve either. Everything that I read and heard at the time said I would pressurize the crankcase and blow the seals out!
When I put the F150 together I left the PCV disconnected as well. The truck always had a thin film of oil covering the engine bay. In an attempt to control the oil I reconnected the PCV with a new valve. Much better!
I then setup the PCV system with a modern PCV valve for my MGB and had great results.
I used store brand PCV valves, like First Fox said, these sometimes leak and push the dipstick out.
When I put the F150 together I left the PCV disconnected as well. The truck always had a thin film of oil covering the engine bay. In an attempt to control the oil I reconnected the PCV with a new valve. Much better!
I then setup the PCV system with a modern PCV valve for my MGB and had great results.
I used store brand PCV valves, like First Fox said, these sometimes leak and push the dipstick out.
Is the recommendation then, to use a genuine FoMoCo PCV, as fitted to one of Ford's supercharged or turbocharged production cars?
And, a somewhat related 'converting-to-turbo' question... what to do about a vacuum modulator, specifically for a C6 trans, behind a turbocharged 300" with a max. of 8-9psi ?
TIA
J.R.
SoCal
And, a somewhat related 'converting-to-turbo' question... what to do about a vacuum modulator, specifically for a C6 trans, behind a turbocharged 300" with a max. of 8-9psi ?
TIA
J.R.
SoCal
I run a manual trans so I can't speak from experience on the modulator issue, but I seem to remember there having to be a check valve in place to the modulator as well as a "t" fitting to bleed the boost signal. Sorry I can't be more specific I don't remember it well.
I'll see if I can find the post for you.
I'll see if I can find the post for you.
What you want to do is run a check valve with a TINY hole to bleed it off. I bought one with a built in T on the transmission side of the valve, epoxied it closed, then used my ... #47? drill bit on it. This will, under vacuum, act normally. and Under boost not let any reach the modulator, while still allowing the modulator to breath 
Im unsure of why exactly it needs the "vacuum" but it does.
Im unsure of why exactly it needs the "vacuum" but it does.since you're doing draw-through you can hook it between the carb and turbo and you'll still get the vacuum signal like you would with an NA engine.
the other option that i've been looking at for vacuum brakes is a vac canister like modern cars have, with a check valve. more plumbing but it would keep your brakes working under boost... for emergencies? not sure if i'll need it...
the other option that i've been looking at for vacuum brakes is a vac canister like modern cars have, with a check valve. more plumbing but it would keep your brakes working under boost... for emergencies? not sure if i'll need it...
Like motzingg said, you should be fine using vacuum from under the carb in a draw through. But couldn't you also just plumb the PCV from the valve cover to the fresh air intake?
That is how the routing on my 2005 PSD (turbo 6.0) is routed from the factory. There is a 1" tube going from the driver side valve cover to the fresh air intake, just in front of the turbo.
Its an awful system, the entire intake tract is coated with oil, the compressor is coated in oil, the CAC tubes are coated in oil, it ruins the turbo CAC boots (oil soaked), it cokes onto the EGR valve, it coats the entire intake manifold..
Oh wait, I was trying to tell you why you should do it, not why you shouldn't.
At any rate, that is how 6.0 and 6.4 Powerstrokes are routed from the factory. On the 6.7 Powerstroke they do something very similar, but they invented a "Crankcase vent oil separator" its an interesting piece of engineering designed to capture the oil from the crankcase prior to ingestion by the turbo.
Other alternatives that the guys at powerstroke.org have suggested..
road draft tube
welding a bung into the down pipe in the exhaust and allowing the venture effect to suck the pressure out.
Building their own Crank Case Ventilation capture device (think round tube, 1" hose inlet and outlet, stuff it with steel wool, crank case vent comes in one side, the air mixture cools, and the oil falls out of suspension, then the 'clean' air goes out the other side to be sucked into the intake tract ahead of the turbo)
also, FWIW, 2003+ Powerstroke trucks have factory mounted vacuum pumps for operating the HVAC and ESOF (electronic Shift On the Fly) hubs. The pumps and resevoirs are on the passenger side fender liner, they look like a small coffin, black plastic about 10" long 5-6" wide with a slight dome to the top.
lots of luck.
-ron
That is how the routing on my 2005 PSD (turbo 6.0) is routed from the factory. There is a 1" tube going from the driver side valve cover to the fresh air intake, just in front of the turbo.
Its an awful system, the entire intake tract is coated with oil, the compressor is coated in oil, the CAC tubes are coated in oil, it ruins the turbo CAC boots (oil soaked), it cokes onto the EGR valve, it coats the entire intake manifold..
Oh wait, I was trying to tell you why you should do it, not why you shouldn't.
At any rate, that is how 6.0 and 6.4 Powerstrokes are routed from the factory. On the 6.7 Powerstroke they do something very similar, but they invented a "Crankcase vent oil separator" its an interesting piece of engineering designed to capture the oil from the crankcase prior to ingestion by the turbo.
Other alternatives that the guys at powerstroke.org have suggested..
road draft tube
welding a bung into the down pipe in the exhaust and allowing the venture effect to suck the pressure out.
Building their own Crank Case Ventilation capture device (think round tube, 1" hose inlet and outlet, stuff it with steel wool, crank case vent comes in one side, the air mixture cools, and the oil falls out of suspension, then the 'clean' air goes out the other side to be sucked into the intake tract ahead of the turbo)
also, FWIW, 2003+ Powerstroke trucks have factory mounted vacuum pumps for operating the HVAC and ESOF (electronic Shift On the Fly) hubs. The pumps and resevoirs are on the passenger side fender liner, they look like a small coffin, black plastic about 10" long 5-6" wide with a slight dome to the top.
lots of luck.
-ron