This truck has been here about a week now, and I'd like to keep it around, healthy. In process of rebuilding the carb, I notice a hose from right rear valve cover to a plate between the carb and the intake manifold. No PCV in this line. Left front valve cover has an oil filler-breather cap. My big bro, who also has a '66 F250, promises me that '66s predate required Environmental Equipment. Is PCV part of the EE ensemble? I have researched threads for Crankcase Ventilation and for PCV. While that process was interesting and informative, my inquiring mind still wants to know...was a PCV valve a stock item on my San Jose-built rig? Either way, would a valve be beneficial? Would carb adjustments need be made if a PCV valve were added? Does the hose by itself without a valve constitute PCV? Sweep away the oily smog obscuring my understanding. I need Positive Cranium Ventilation!

 

lb Welcome to FTE hope you will join in the fun here.

Sounds like the pcv valve that goes into the passenger side valve cover is missing. You said the hose is there so just put it in and you will be good to go.

John

 

Should be a PCV in the right valve cover with a hose running to a brass nipple on the rear of the intake just behind the carb. Direct intake manifold vacuum is needed and this nipple may share vacuum with the brake booster if you have one. The breather cap on the left valve cover is correct.

 

If you have a diecast dispersion plate under tour carb base one of several things can be going on. First 66's didn't use the plate on trucks, although some P-Cars did.

Somebody may have added the plate, or you may not have a 66 352CID FE engine, it may be later and something other than a 352.

NEver the less, I would suggest you install a PCV Valve in the end of the "hose" and stick that in the grommet in your valve cover. I can't believe the engine idles without a PCV Valve in it, unless the die cast plate is clogged & restricted with fried gunk.

The PCV relieves internal pressure as well as fumes. If in fact you have an engine which the diecast plate came on, & it is in fact a PCV engine to begin with, for whatever reason, running it without the PCV & Valve will eventually blow out your front & rear crankshaft seals. If you do not have a PCV engine, but it has the PCV parts you're describing, putting it together so it works certainly will NOT hurt and may even help the longevity of the engine.

FBp

 

I have a six, so maybe ignore me, but my six has a PCV valve. It fits down into the rear opening, and doesn't look very conspicuous. In fact, originally I ignorantly thought the hose (which goes to manifold vacuum, as yours does), was directly hooked up, with no valve at all.

Maybe you have a PCV valve and don't know it? Pull the "elbow" out of the valve cover. You may be pleasantly suprised.

Oh -- yes you need one. Its NOT some silly EPA idea (though it does reduce emissions). By removing water and acid vapors from your crankcase, you are keeping you engine cleaner.