where to drill 21 stud intake for PCV?

mumpsimus

mumpsimus

Member
I saved a photo from an old forum thread that I can no longer find. It shows a tiny 1/4" hole drilled into the intake manifold on the passenger side beside the generator. But the PCV that everybody recommended has a rubber grommet that needs a very large 1" diameter hole (Standard V261 PCV, grommet HELP 42322). There isn't a space on the side of the manifold large enough to drill a 1" hole. Anybody out there with a PCV on their 21 stud motor, can you please let me know where you drilled the hole for the PCV and grommet?

The other end of the rubber hose was supposed to go to a 1/4NPT fitting drilled into the intake runner under the carb. But there appears to be a hot air jacket all the way around the vertical intake channels. Do you instead drill into one of the horizontal channels that feeds a pair of cylinders?

Sorry if this has been covered before. I've found lots of forum posts on PCVs in the later motors, but can no longer find that one thread that had info on how to install a PCV in an early 21 stud.
 
pntH6Lq
This was the image that I found a while ago and saved with the tiny hole drilled.
 
Some don"t like the smell or oil vapor of the road draft system. Ford used a PCV system in some enclosed environments such as military applications. I'm not a PCV fan, but a lot of folks are.
 
The Positive Crankcase Valve (PCV) is the best addition ever applied to an engine. The PCV removed 95% of the emissions discharged into the air, and it solved a lot of problems that the common engines had prior to 1963.
The road draft tube type of engine ventilation did not work well when the vehicle was stationary, sitting at a stop light idling, etc.
I have made it a habit to install a PCV system to every old car I have owned since the early seventies.
 
I’m still hoping to hear from somebody who can say where to mount a PCV on a 21 stud motor. Maybe I need to buy a different valve, one that doesn’t require a 1.0” diameter hole in the manifold near the generator?


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JSeery said:
There are PCV valves with pipe threads.
Click to expand...



I think that’s the solution. The grommet type one that was recommended is just too big. I’ll find a valve with 1/4NPT threads. That should be easy to fit beside the generator.


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qmdv said:
why have a pcv to begin with
Click to expand...

The vapors and oil residue coming out of multiple motors, think metropolitan highways + byways, were very very toxic. Not to mention increased skidding issues with the arrival of lite rains. In my youthful, Philly, eyes and heart there was no way the GROWTH of motor travel could continue.

Thankfully the PCV systems changed all of that.!!
Respects paid to paper filters and electronic fuel injection.

.
 
Drill one in the front of the manifold. Find a grommet, drill to suit and PCV of correct size to suit the engine capacity. . You may need to come up with a baffle on the inside if you think it can suck oil..[?] . Hole under the carb drill or use a vacuum plate. Block off the draft tube. Make sure it can still and breath from the vent cap.
 

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I don´t do PCV unless there is a seal on the crankshaft.
Using the slinger and PCV is not a good solution in my book since it will draw in dirt that way....
 
I'm with flatheadmurre, a PCV system on a 21 stud engine with the slinger rear seal is a bad idea. You are pulling unfiltered air into the crankcase and the bellhousing/clutch area has a lot of undesirable stuff in it.
 
Even with the pan vent blocked, PCV probably won't pull enough vacuum to worry about this issue. Forget a PCV valve anyway. Simply entrain the crankcase stink into the air cleaner with a hose from chrysler-style oil filler cap. Jack E/NJ
 

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