Positive Crankcase Ventilation PCV Direction
07-24-2010, 03:00 PM
#1
3rd Gear Member
Thread Starter
Join Date: Mar 2010
Location: California
Posts: 611
Positive Crankcase Ventilation PCV Direction
I did a search for this and came up short, so I figure I will ask a newbie question. When looking at the first generation 302 Mustang engines and comparing them to the second generation Mustang II 302 it seems like the Positive Crankcase Ventilation PVC direction is reversed. So does it matter which valve cover holds the breather and which has the PCV valve, and simply can the covers be swapped from left to right? (physically they seem to fit on either side)
On the first generation the air enters the air cleaner then comes out of the front of the cleaner through a rubber hose and down the driver side valve cover into the cylinder head and into the block, through the oil pan and up the other side through the block, past the head, out the passenger side valve cover, by the PCV valve through another rubber hose located in the BACK of the engine and into the carburetor spacer or the base of the carb itself. See first picture below.
On the second generation the air enters the air cleaner in the back of the engine then descends down the passenger side valve cover into the cylinder head and into the block, through the oil pan and up the other side through the block, past the head, out the driver side valve cover, by the PCV valve and into the carburetor spacer or the base of the carb itself in the front of the engine. See schematic diagram below:
Why do I care, why am I asking?
Well in the process of removing all of the SMOG stuff off of my 1976 engine I would like to use a non EGR intake with non EGR carb spacer and I don't want to have to run a long rubber hose from the front of the driver side valve cover all the way to the back of the carb spacer in the back of the engine, if I can just swap the valve covers then the PCV port will be on the back of the valve cover closer to the port on the carb spacer. See the current and proposed valve cover, carb spacer layouts on concrete below.
For the inlet I just plan on using a breather cap, (since I don't own a stock air cleaner, and will probobly opt for one of them round chrome jobbies with no inlet nipple on it), so I am mostly concerned with the PCV valve side as it tends to spew oil.
On the first generation the air enters the air cleaner then comes out of the front of the cleaner through a rubber hose and down the driver side valve cover into the cylinder head and into the block, through the oil pan and up the other side through the block, past the head, out the passenger side valve cover, by the PCV valve through another rubber hose located in the BACK of the engine and into the carburetor spacer or the base of the carb itself. See first picture below.
On the second generation the air enters the air cleaner in the back of the engine then descends down the passenger side valve cover into the cylinder head and into the block, through the oil pan and up the other side through the block, past the head, out the driver side valve cover, by the PCV valve and into the carburetor spacer or the base of the carb itself in the front of the engine. See schematic diagram below:
Why do I care, why am I asking?
Well in the process of removing all of the SMOG stuff off of my 1976 engine I would like to use a non EGR intake with non EGR carb spacer and I don't want to have to run a long rubber hose from the front of the driver side valve cover all the way to the back of the carb spacer in the back of the engine, if I can just swap the valve covers then the PCV port will be on the back of the valve cover closer to the port on the carb spacer. See the current and proposed valve cover, carb spacer layouts on concrete below.
For the inlet I just plan on using a breather cap, (since I don't own a stock air cleaner, and will probobly opt for one of them round chrome jobbies with no inlet nipple on it), so I am mostly concerned with the PCV valve side as it tends to spew oil.
07-24-2010, 04:27 PM
#2
6th Gear Member
Join Date: Jan 2007
Location: AR
Posts: 5,469
The direction of flow pertains directly to whether the engine was built for the northern or southern hemisphere.
Northern hemisphere cars will draw from the left and southern hemisphere cars will draw from the right.
This all has something to do with thermodynamic flow principles.
Northern hemisphere cars will draw from the left and southern hemisphere cars will draw from the right.
This all has something to do with thermodynamic flow principles.
07-25-2010, 08:53 AM
#4
3rd Gear Member
Thread Starter
Join Date: Mar 2010
Location: California
Posts: 611
After I read this for the first time I thought what the Frock, then I looked at who the source was, and I noticed it was you JMD, a guy who I have a lot of respect for, having seen your work, (pictures etc.) and began justifying it in my little head, so don't joke around like that man, you almost had me, LOL, jk
07-25-2010, 08:07 PM
#5
6th Gear Member
Join Date: Jan 2007
Location: AR
Posts: 5,469
Sorry, I couldn't help it 
Anyway, you can just use a little filter in the valve cover you want the air to go into.
http://www.summitracing.com/search/?...20filter&dds=1
Anyway, you can just use a little filter in the valve cover you want the air to go into.
http://www.summitracing.com/search/?...20filter&dds=1
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