Blowby pressure problem at WOT - how to solve and keep the PCV system ?
#1
Blowby pressure problem at WOT - how to solve and keep the PCV system ?
Hello,
I will try to explain my problem best I can. I have built a 350 TPI engine, 6 speed manual transmission, Edelbrock Performer heads, Comp Cam 305 cam, High Flow Base and a SuperRam on top.
The SuperRam was the last part I installed and since I have a blowby problem at WOT when I accelerate. But really only when I'm doing a hard acceleration in two or more gears by full throttle, than I have a nice white cloud in the mirror ... First time I was shocked about that, than I have spoken to some guys and they said me to take the PCV valve on driver side out, let the hole in the valve cover open and close the hose that goes to the intake. And after this there wasn't no longer any white clouds ...
So I suppose this is a real blowby problem and I have too much crankcase pressure on the system ... Now the last months I have had several recommendations what to do, but I'm not sure at all and so I prefer to ask what are your opinions ...
Some people say me to simple close the PCV hose to the intake and set a breather in the hole on the valve cover in place of the PCV valve on driver side ...
Other think It's better to place two breathers, one on each side ...
I'm sure the breather would solve the pressure problem but I have read a lot of threads here in the forum. There is one from 2003... " PCV or no to PCV, that is the question " ... very interesting, but there is no real solution at all too... https://www.thirdgen.org/forums/tech...-question.html
Most people there explain, why it is better to keep the PCV system in place and I think it would be better, but how to do this and eliminate at the same time the pressure?
There is one installation in this thread at page 1 from member 1bad91Z He installed a breather and the PCV valve on the same valve cover. Seems nice and for the pressure problem this will work well I suppose, but in my opinion PCV couldn't no longer work at all because it need to create a vacuum and that is no longer possible with the breather in the same valve cover ? The system will suck fresh air from the breather and not the crankcase gases, or not ?
A second idea is the breather and catch can solution from member B4Ctom1 also on first page, the picture just below. He has a catch can in the PCV hose on driver side and on passenger side instead of the hose that comes on TPIs from the throttle body to the valve cover a breather can or simple breather would be the same I think. That seems okay for PCV vacuum but will this work for the pressure ? because the breather is on the opposite site of the venting flow direction. Will this setup be able to reduce pressure and work correctly?
If someone has any idea or has had the same problem or a nice solution, it would be great to let me know. I absolutely need to change something because I don't want to broke my seals ...
Thanks,
Pac
I will try to explain my problem best I can. I have built a 350 TPI engine, 6 speed manual transmission, Edelbrock Performer heads, Comp Cam 305 cam, High Flow Base and a SuperRam on top.
The SuperRam was the last part I installed and since I have a blowby problem at WOT when I accelerate. But really only when I'm doing a hard acceleration in two or more gears by full throttle, than I have a nice white cloud in the mirror ... First time I was shocked about that, than I have spoken to some guys and they said me to take the PCV valve on driver side out, let the hole in the valve cover open and close the hose that goes to the intake. And after this there wasn't no longer any white clouds ...
So I suppose this is a real blowby problem and I have too much crankcase pressure on the system ... Now the last months I have had several recommendations what to do, but I'm not sure at all and so I prefer to ask what are your opinions ...
Some people say me to simple close the PCV hose to the intake and set a breather in the hole on the valve cover in place of the PCV valve on driver side ...
Other think It's better to place two breathers, one on each side ...
I'm sure the breather would solve the pressure problem but I have read a lot of threads here in the forum. There is one from 2003... " PCV or no to PCV, that is the question " ... very interesting, but there is no real solution at all too... https://www.thirdgen.org/forums/tech...-question.html
Most people there explain, why it is better to keep the PCV system in place and I think it would be better, but how to do this and eliminate at the same time the pressure?
There is one installation in this thread at page 1 from member 1bad91Z He installed a breather and the PCV valve on the same valve cover. Seems nice and for the pressure problem this will work well I suppose, but in my opinion PCV couldn't no longer work at all because it need to create a vacuum and that is no longer possible with the breather in the same valve cover ? The system will suck fresh air from the breather and not the crankcase gases, or not ?
A second idea is the breather and catch can solution from member B4Ctom1 also on first page, the picture just below. He has a catch can in the PCV hose on driver side and on passenger side instead of the hose that comes on TPIs from the throttle body to the valve cover a breather can or simple breather would be the same I think. That seems okay for PCV vacuum but will this work for the pressure ? because the breather is on the opposite site of the venting flow direction. Will this setup be able to reduce pressure and work correctly?
If someone has any idea or has had the same problem or a nice solution, it would be great to let me know. I absolutely need to change something because I don't want to broke my seals ...
Thanks,
Pac
#2
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Join Date: Mar 2017
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Car: 1986 trans am
Engine: 305/350
Transmission: 5 speed
Axle/Gears: 3.27
Re: Blowby pressure problem at WOT - how to solve and keep the PCV system ?
did you figure it out,if not try some of the things you mentioned and you will have your answer.
#3
Re: Blowby pressure problem at WOT - how to solve and keep the PCV system ?
I just picked up a high torque mini starter, there are only two terminals for me to attach wires to although I have more than two wires. Can anyone help me out? I know which is for the battery and I know which one is for ignition but these other two I dont know where they're for.
#4
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Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: Blowby pressure problem at WOT - how to solve and keep the PCV system ?
All the wires with big terminals the same size as the one on the batt cable go on the stud along with the batt cable. (size to size) The purple wire with the small terminal goes on the ... ummm... uhhhh,,,, duhhhhhhhh... not sure which stud that one goes on.
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