got sludge? thinkin of synthetic oil...

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IQ52 said:
Come on Kim, enlighten me. What is it's purpose? When did they first come into use and why? I'm willing to learn.
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Pressure is "sucked" from the motor via one of the full time ports on the carb. I had the carb off my car a while ago and forgot to put the PCV hose back on, went for a test drive and got oil all under the hood, hooked it back up and now its fine. If you are really interested in learning about the use/need of a PCV, Google it, there is a wealth of knowledge on the introweb...
 
AH HA, crackedback, thank you, we have a voice of reason!

All those recommending that others read up on PCV valves...have you done so first?

Our Federal Government is the reason we needed PCV valves in the first place.

If you want to use it in an attempt to pull a vacuum in the crankcase to enhance ring sealing, okay. But there are far more effective ways to do so than burning low octane oil vapors.

Heck you could run a electric fuel pump and hook the inlet side of your mechanical fuel pump to a valve cover, vent the outlet side to the atmosphere and draw a nice crankcase vacuum, seen it done. There are vacuum pumps and exhaust gas driven pan evacuation systems. But the PCV is for Federally mandated emissions control.
 
Hey, I occasionally have lucid moments of clarity! :)

The milkshake deal... SB timing chain covers are a notorious source of water leaks into the crankcase. The aluminum rots, gets pinholes, which leak into the timing chain area, flowing to pan. I had one 318 that you could hear water running into the pan as fast as you poured it in the radiator.

If you pull the dipstick and the entire dipstick has that brown goop on it, you have a bad leak. Normal levels of condensation in the crankcase won't usually foul an entire charge of engine oil. Usually takes a decent amount of water to do that.
 
And the answer is... not the PVC valve (I never did put one of those on) and not any kind of water leak into the oil. The milky brown goo at the top of the dipstick eventually went away after a few oil changes and longer drives in the car.

PS - it's been 9 years since I've been on Abodiesonly, I can't believe that much time has gone by. I'm not sure if anyone will even see this update now, but thought I would do it anyways.
 
Thanks Kim! I went to live in KC for a while and then moved to Spokane, WA, where I'm at now. Didn't do anything new with the Demon, just drove it. In the meantime I restored and built a monster 4X4 truck, that got stolen last year. It was a 1980........Chevy square body. Dm, did I just admit to a chevy here on FABO?! I'm gonna get kicked off! lol
 
screeminDemon said:
And the answer is... not the PVC valve (I never did put one of those on) and not any kind of water leak into the oil. The milky brown goo at the top of the dipstick eventually went away after a few oil changes and longer drives in the car.

PS - it's been 9 years since I've been on Abodiesonly, I can't believe that much time has gone by. I'm not sure if anyone will even see this update now, but thought I would do it anyways.
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You SHOULD a be running a PCV valve. There isn’t a single reason not to.
 
OK, question was asked a long time ago, and this may have been answered dozens of times since, but PCV systems appeared early sixties. Before that, we had road draft tubes. Tube came off valve cover, dropped down below the engine, air passing by the bottom of the tube sucked out crankcase pressure/fumes/etc. So fresh outside air got sucked in through the oil breather cap, then crankcase fumes got sucked out through the road draft tube. Didn't work when the car wasn't moving, and was not very efficient at low speeds. Plus there was the issue of pollution when they did work. That's why they got replaced by PCV valves. You can see the road draft tube in this illustration of a 1956 Plymouth chassis. It's the black thing on the rear of the passenger side valve cover, running down to the bottom of the motor.

chassis.jpg
 
I had a 1962 Oldsmobile Starfire. 394 CID/345 HP. It had a road draft tube from the factory. It didn't work well below 45 MPH. If you look at early 1960's photos of the California freeways, you'll see smog in the air, and an oil stain just to the right of the centerline of the engine. I think you could call it the first version of emission controls, although it didn't detract from performance that much. Thoughts from an old man.
 
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