Ford Racing Valve Covers and EFI

$uperstang

New Member
Jul 20, 2004
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Detroit, MI
Ok, So I purchased a nice new set of Polished Ford Racing valve covers and want to know about the set-up solutions. Since the 5.0 is set-up with a closed crank case design I was planning on plugging the tube on the throttle body. Then the hole that is on the passenger side I was planning on plugging and on the hole on the driver side I was going to install a closed breather so I can use that side to fill my oil. The Cobra intake poses no clearance issues so I can still get oil in there as I have a one inch spacer and no A/C. What do you guys thik. Is it ok to close up the crank case?
 
It is ok to eliminate the tube coming off the throttle body and run a breather, however if you do this you will also need to eliminate the PCV valve. If you run a breather with the PCV still in place, you are allowing un-metered air in to your engine, which can affect the air/fuel ratio. I plugged off the PCV on my intake. I then pulled out the PCV valve and replaced it with a very small K&N breather.
 
$uperstang said:
Ok, So I purchased a nice new set of Polished Ford Racing valve covers and want to know about the set-up solutions. Since the 5.0 is set-up with a closed crank case design I was planning on plugging the tube on the throttle body. Then the hole that is on the passenger side I was planning on plugging and on the hole on the driver side I was going to install a closed breather so I can use that side to fill my oil. The Cobra intake poses no clearance issues so I can still get oil in there as I have a one inch spacer and no A/C. What do you guys thik. Is it ok to close up the crank case?
Do NOT delete the PCV system and run breathers as it's not as efficient as the PCV system at evacuating the crankcase of corrosive vapors. Running straight breathers is also a passive system that only equalized crankcase pressure and doesn't evacuate the crankcase like the POSITIVE crankcase evacuation does. Straight track cars may run breathers, but they usually have a way to make it into a positive system like a vacuum pump or connecting hoses to the headers in order to create the suction that the PCV valve does in our engine. They also rebuild their engines more often than street cars. Here's the oil fill cap that you should run in order to maintain your PCV system with those valve covers: View attachment 497156 part #M-6766-D302 from from http://www.fordracingparts.com. The price is only $7.50 so it's not expensive either.
Tim
 
18mustangs said:
Do NOT delete the PCV system and run breathers as it's not as efficient as the PCV system at evacuating the crankcase of corrosive vapors. Running straight breathers is also a passive system that only equalized crankcase pressure and doesn't evacuate the crankcase like the POSITIVE crankcase evacuation does. Straight track cars may run breathers, but they usually have a way to make it into a positive system like a vacuum pump or connecting hoses to the headers in order to create the suction that the PCV valve does in our engine. They also rebuild their engines more often than street cars. Here's the oil fill cap that you should run in order to maintain your PCV system with those valve covers: View attachment 497155 part #M-6766-D302 from from http://www.fordracingparts.com. The price is only $7.50 so it's not expensive either.
Tim

Cool So I just figured it out as I posted this questions I just purchased teh FMS 6766-G302 breather with PCV almost like the one you show here and I purchased a FMS oil cap for the other side. I will just hook the tube from the TB to this new breather set-up. Cool?
 
$uperstang said:
Cool So I just figured it out as I posted this questions I just purchased teh FMS 6766-G302 breather with PCV almost like the one you show here and I purchased a FMS oil cap for the other side. I will just hook the tube from the TB to this new breather set-up. Cool?

If both caps are for a closed crankcase you're good to go. Just connect the tube from the throttle body to the port on the oil filler cap and you're PCV system is still fully functional. While you're at it, you may want to replace the PCV valve, PCV filter, and PCV grommet if you haven't done it in a while. All three together at ford is about $20 total.
Tim
 
18mustangs said:
If both caps are for a closed crankcase you're good to go. Just connect the tube from the throttle body to the port on the oil filler cap and you're PCV system is still fully functional. While you're at it, you may want to replace the PCV valve, PCV filter, and PCV grommet if you haven't done it in a while. All three together at ford is about $20 total.
Tim

Yes both are for closed crank case design. I will hook the tube from the TB to this new breather cap and have everything work like stock. I will also change the PCV unit. Thanks for the help
 
Suggestion - go to the dealer to re-new your pcv components. Rubber grommet, pcv valve and the oil trap/screen under the grommet can be had for about $20. The grommet gets rigid over time and often doesn't seal well around aftermarket pcv valves. And the screen clogs with oil/grunge. If you don't want to replace the screen, place it in a glass jar with lid, and cover it with acetone overnight. That will clean it right up.