Well forums are great for no question is a dumb question, so here's mine 69 F250 rebuilt 390 although there are some things the shop did I didn't really like .... I have moisture that sprays out the exaust on cold starts not to much but I live in a dry climate 55/65 winter's I thought that was odd I haven't run a old cast iron rebuild in 20 plus years so I don't know if that's normal ?.
I have 1,700 miles on the 390 for the first 1,000 or so there was alot of vapor coming from 1 side of the breathers I'm running both to the carb through the air cleaner ..

What did they do I didn't like ?
1 used cork gaskets on intake
2 reused my old push rods and I don't think they machined my old rockers at all / rail type there noisy
3 did a crap job at cleaning out my intake I should had replaced with performer but when I showed up to pick it up the had it on with the rockers as a long block .
I have a comp 265/275 dual energy cam
They used the engine tech rebuild kit high volume oil pump 50 psi driving 19/20 idle I broke in the cam and now use royal purple HP zinc oil my third or fourth change first 2 I seen silver City in the oil 3rd change it looked good no silver in the oil is it normal to have that vapor from the breathers and moisture from the exaust on a rebuild ?????
Also first 500/1,000 miles or so it used oil maybe a quart at 300 miles or so now it seems fine stays full break-in process I guess seating the rings valves etc although I got on it pretty good never really babied the motor .

 

When it's cool enough and/or humid enough it'd be weird to not see water vapor out the tail pipe during cold start. When ever you burn hydrocarbon fuel (gas, propane, wood, etc) moisture is produced. It has to come out the tail pipe. Some sneaks past the rings and into the crank case. Need to run the motor at least 180F to drive the moisture out of the crankcase or it will build up on the inside of the valve covers.

Probably shouldn't see vapor out the valve cover breather if you have a PCV valve. When it's cold enough (like 20F) might see vapor out the breather if you don't have a PCV valve.

 

Also think about the gas that the engine burns. There is alot of water i in the gas now a days. Thanks to the corn that is used.

 

Thanks that gives me peace of mind I only see the vapor when I pull the breather off for awhile I was smelling the vapor of the oil inside the cab so I put both breathers on the A/C , before I had 1,000 miles
I could smell the royal purple . I have a additional temp gauge on the water neck when it comes out of the cylinders by the thermostat it runs around 190
The stock temp gauge is about 10 degrees cooler cooler water coming from radiator but cylinder temp is always 190 oil filter is hot enough to burn my hand so think that's ok . Overall today's gas sucks for older carb cars that's the theme ... 91 octane here only with water and crap in it

 

What do you mean when you say you ran both breathers to the AC? The passenger side rear needs to have the PCV and the drivers side is the breather that goes to the AC. Hopefully you didn't omit the PCV.

 

The truck didn't have a air cleaner on it when I bought it I pretty much had to redo everything well I see guys running that filter looking breather I have both lines coming from each valve cover going to the air cleaner . The moroso or Mr gasket that chrome round breather that pops into the valve cover hole with a fiber filter inside and a nipple for a rubber hose should I run the filter type pop in to the passenger side and just hook up the drivers to the air cleaner with the hose ?

 

That kinda makes sense now since the driver's side with the hose will suck the air from the passenger side filter type breather through the carb from the engine bay through the filter pop in I had both hooked up to the air cleaner ....
Good thing I don't have many miles on it yet 1,700
Gonna change that out asap

 

Do you have a pic k of haow it should be routed !

 

This is how the factory did it. PCV on passenger side rear, breather fresh air front drivers side.

 

So in the pic the rear is bieng sucked in all the time through the intake I'm assuming the bent over hose is going to a fitting on the intake there ? And on the driver's side it gets ventilation through the carb air cleaner , I actually did hook mine up like that at one time only with the rear side it would stumble out and act like it had a vacum leak when I hooked it up to manifold vacum like that .
I see some guys running a filter there in the rear and one to the carb only , I also tried to hook the rear side up to the back of the carb as well it did the same thing stumbled out on me why ? Don't know that's why I just hooked both up to the air cleaner ports it's a K&N filter top 16" air cleaner open they didn't have a pcv valve at that time did they? I had that style breather on my stock valve covers I have aftermarket now there was no valve in it only a gauze type filter inside

 

There is a PCV valve in the valve cover breather on the passenger side. That's it the hose is connected to. The PCV valve is sitting in a rubber grommet in the valve cover breather.

 

Ok thanks for the pic I'm not running one maybe with only 1,700 miles it's not that bad but I did notice oil leaks starting I'm going to add one there I looked it up on you tube how it works it sounds lame but when I bought the truck all kinds of stuff up there was missing I pulled the motor out and took it down for rebuild put it back in but the pcv on a FE especially I shouldn't had over looked that .
Also when I tried it to full vacum there wasn't a pcv valve in it that might be why it stumbled out on me .

 

Either need a properly working pcv valve or nice sized breathers to vent the crank case. If you get a pcv valve, check it isn't sucking gobs of oil. If it does, the hose to the pcv valve can be restricted by inserting a smaller hose into it. It's a balancing act to vent the crank case enough but not too much. Too much or not enough are both bad for a motor.

My valve covers have two holes each where I have after market breathers. My valve covers stay clean inside and out. Once a year I have to rinse oil vapor out a of a breather or two. Got rid of the pcv valve because I got tired of seeing oil vapor going through my intake via the pcv valve. I tried various baffles and even an adjustable pcv valve when finally I talked with a guy who builds and sends FE's all over the country. He told me I could just vent it so I did and like the results.

 

I hooked up a pcv yesterday I had the chrome breather with a built in pcv , just had to back off my idle screws a little , it ran alot leaner with that extra air going into the intake at idle , left the driver's side hooked up to the air cleaner see how that works out.
I was starting to get some leaks from the timing cover and oil pan see if not running a pcv was the cause of the leaks after a few road trips