yeah
The gang’s all here
Hey guys quick question . Could I run the pcv of the back port on my intake manifold instead of the carb ???
Could I run pcv of the intake manifold instead of the carb ?
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yeah
The gang’s all here
Dammit picture is flipped , sorry . But yeah could I run the pcv to that 90 degree fitting thst I have on the back of the intake manifold instead of the carb ???
Thank you
Peter
Thank you
Peter
mguner
How many is too many?
^^^ What he said. The manifold ports are for dedicated vacuum supply to brake booster etc... and will not bode well for calibrated vacuum leaks drawing in crank case vapors.
yeah
The gang’s all here
Ok guys I will not run it off that port and run it off the carb . Thanks you so much
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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The rear cylinders will tend to run lean at idle and light tip-in, and that makes it a bear to tune.If you flip the carb over you will see how the carb manufacturer handles the problem.
mguner
How many is too many?
Unless he has one of those rare carbs without the PVC for Fords....
famous bob
mopar misfit
a lot of intakes have a 3/8" port in the rear of the plenum that can be used. ever thot about drilling and tapping for a hole in front and back? u could tee the pcv line so it would run to both, for more equalization of the venting. I have to pull my intake to reverse some oil mods. I did anyway, so I`m going to take a long look at the front and rear thing.
jimjimjimmy
lobsterman
my 950hp has no vac port and I run my pcv in the manifold port seems to work great.
I may put a vac port in my 2 inch spacer in the future .
I may put a vac port in my 2 inch spacer in the future .
Many race engines don't use pcv's. That's why you see multiple valve cover breathers. You have to release the internal pressure somehow. The drag racers use a vac-u-pan system where the fumes are sucked out by a tube in the collector in the header. Years ago before Federal Emissions rules there was a downdraft tube that would suck the fumes out as the car goes down the road. Another venturi effect system.
Norway-dart
Well-Known Member
its free hp to get as low as possible pressure inside the engine
its free hp to get as low as possible pressure inside the engine
And internal pressures cause seals and gaskets to blow out. That's why every engine, transmission, and rear axle has a vent.
mguner
How many is too many?
There are also high dollar belt driven and electric evacuation pumps used on race engines. Good as mentioned for leak prevention but also extra ponies with the negative pressure.
Not TOTALLY true (I'm being pedantic...), my '53 Buick doesn't have any rear axle vent.
I figured this out after I had it rebuilt and it blew out the pumpkin gasket. Apparently, the old seals were felt, and they must have let enough pressure by that Buick got by without a vent. I am now running a vent tube through a brake bleeder screwed into one of the back cover bolt holes (which is open). I put an inline fuel filter at the end and now it's vented.
Just thought I'd share a weird story...carry on!
nm9stheham
Well-Known Member
As said, you are just asking for oil leaks and oil in the wrong places (like down the intake valve guides).
Breadburner
Well-Known Member
I have read on certain engines a vac system can be worth an additional 30 Hp.......
moper
Well-Known Member
Most engines benefit because it helps ring seal even on plain pistons. But that doesn't mean it's great technology for your street car. They tend to wear out quickly when you put them in an environment like a street car.
You can run the PCV off the manifold - but it has to be from the plenum area, and if it's possible, you're better off putting it into a spacer or something that pushes it as far from any individual port as you can for the reasons noted.
You can run the PCV off the manifold - but it has to be from the plenum area, and if it's possible, you're better off putting it into a spacer or something that pushes it as far from any individual port as you can for the reasons noted.
dano
Evil Handy Man
And make sure you run a complete PCV system. You should have a tube from the other Valve cover ran to a port on your air cleaner. No Valve cover breathers.
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