390 PCV problems (*PICS*)

[willowbilly3]

Do you have a vent side on your crankcase ventilation?
On a stock engine it would be a hose from the valve cover to the air cleaner and had a small foam element onside the aircleaner. This not only serves to allow the pcv valve to pull clean air through the engine but under certain conditions (like hard acceleration) there is more crankcase vapors than the pcv can handle so the vent side actually lets off the excess pressure.

[bugser]

The way I see it is you've got about 4 inches of hose going vertical before it goes to the carb. So,every time vacuum pulls the pcv open,some oil/vapors get into the hose. The air gets to go the whole trip,but the oil can't make it all the way up the hill. When the pcv closes,the oil stays in the hose.

Just a thought.

[ToughOldFord]

Don't know if this is your problem, but I see you're running all hose on that PCV so I'll throw this in here just in case:

The after market hose we get for our PCV is way thinner than the stock rigid hose and cannot stand up to the high vacuum very long. I used new hose when I put my 390 together and after short use noticed the hose looked narrower than it should. I revved the engine while looking at it and saw the hose was sucking in on itself, (collapsing), and thereby cutting off the PCV all together. I bought some copper tubing at the hardware store and hard plumbed the PCV system, using hose to only connect the ends. Problem solved.

[kid]

Hey what is that read cap sticking up behind the Thermostat?

[ToughOldFord]

That's a cap off of an anti-freeze jug. The intake is from a '62 T-Bird so it has that pipe there for adding oil. Problem is I can't put a regular oil cap on it because it then interferes with the intake snout on the air cleaner.

[DuckRyder]

What kind of oil pump did you use when you built it?

How much oil are the heads retaining?

All the drainback holes clean?

[kid]

That's a cap off of an anti-freeze jug. The intake is from a '62 T-Bird so it has that pipe there for adding oil. Problem is I can't put a regular oil cap on it because it then interferes with the intake snout on the air cleaner.

Right on.

[blue68]

What kind of oil pump did you use when you built it?

How much oil are the heads retaining?

All the drainback holes clean?

Used a Melling HV oil Pump with Clevite Hardened Shaft. Every drainback hole has been cleansed. Block was vat cleaned and heads were fully re-done and surfaced. How can I tell how much oil the heads are retaining?

[kid]

Lift the valve cover on one side or the other and then start the engine. At an idle it should not pour out of the cover. Check the Oil level while running and see how low it is compared to shut down. There is less than 1/4 a quart in the oil galleries and another 1/4 in the rocker shafts.

Old Hi Po motors had dipsticks that showed full when you were a quart or even two over because the motors pumped 2 to 4 quarts up into the heads and valley at high rpm.

[blue68]

Old Hi Po motors had dipsticks that showed full when you were a quart or even two over because the motors pumped 2 to 4 quarts up into the heads and valley at high rpm.

Oh gosh.. that sounds pretty bad. Never even thought about that occuring.

I fixed the problem with the PCV hose getting saturated. I did exactly what ToughOldFord did.. I used a peice of flexible metal tube and short hoses with clamps on each end. Worked like a dream. I'll try to snap some pictures tomorrow or something.

[DuckRyder]

It is widely believed that when you put a high volume oil pump in an FE that you should restrict the oil feeds in the heads to the rockers.

The drain holes look huge but the head bolts run through them as well and there is actually a pretty small passageway there.

With stock rocker assemblies, a 80-90 Holley jet in the oil feed under the rocker stand is about as small as you want to go.

If you are pooling oil in the heads than that might be your fix.

If the heads are holding a lot of oil, it will make it easier for the valve to suck up the oil.

Sounds like you have at least partially fixed it though.

[blue68]

Here's what I did. Works like a dream so far!

[70_F100]

Is that flexible conduit that you used?

[fordman]

thats what it looks like. not right but it does work. it also kind of gives that chrome look to the enigne. i wouldnt use it myself. unless it was over a rubber hose.

[70_F100]

Looks good, but it might create a new set of problems.

If it's not underground conduit (which I doubt it is), it's not totally sealed and could have a vacuum leak. Just asking for a burned valve.

For a chrome look, some stainless steel braided hose connected the same way would work fine.