crankcase vent problemo

[cs daytona]

well i was just looking over my 89 daytona shelby that i just bought, and i have this problem. when i drive it "kinda" hard, oil blows out of the dipstick like real bad. my #3 cyl does have low comp (100psi). the blowby is real bad thru the crankcase. so is the blowby on cyl 3 bad enough to where the boost is shooting thru the rings and blowing oil thru the dipstick?

cus.....i also found that the hose off the valve cover (the same rubber thing that holds the pcv valve) that goes to the airbox, is blocked off with a bolt. could this also cause this massive blowby problem? that should be a breather, right? can i buy a catch can with a breather on it? or would just a breather work?

i just want to get it to where i can drive the damn thing without oil spewing everywhere.

i plan on rebuilding it anyways, but just needing to see if it can wait for now.

any help is greatly appreciated

[cordes]

The hose with the bolt in it should most likly go to the air box. That draws vac while you are in boost to help draw the pressure out of the crank case. With low compression, you will have to stay on top of things to keep every thing intact if your PCV system is in shambles.

Look out, as excessive pressure in the crank case has been said to pop out the cam seals...

[puppet]

Get a vented, filtered oil fill cap ... the one with the hole in the top. It'll fit under the hood just fine. If this doesn't help ... the engine has big problems.

[Dave]

The hose with the bolt in it should most likly go to the air box. That draws vac while you are in boost to help draw the pressure out of the crank case. With low compression, you will have to stay on top of things to keep every thing intact if your PCV system is in shambles.

Look out, as excessive pressure in the crank case has been said to pop out the cam seals...

On top of that, you risk blowing the rear main seal. That one sure isn't fun.

The hose being blocked off with a bolt will cause massive blowby. Think of it this way... from factory the vehicle typically has two ways to draw pressure out of the crankcase... (1. Intake manifold & (2. Intake to the turbo. Both are designed great to pull vaccum. But since most all of us design our own intakes, we lose this part.

Now, again with "most people," we just put a breather on the end and be down with it, hoping the crossing air creates a Venturian (heh, I think that's right) effect, pulling pressure out of the crankcase. But it's not enough.

Your problem is two things. The rings could be so unseated that boost is blowing right by them, and while in any kind of boost at all (at 0psi) the PCV valve closes the source from the intake manifold, preventing boost from leaking into the VC, but now has nowhere to draw vaccum since the intake to the turbo side is completely shut off.

What you need to do is this. Uncork that pipe and run a 5/8" heater hose to the top of your k-frame with a foam pad from AutoZone on it. They're like $4. Works good for the time being. Or you could buy a catch can and I'll help you along with the install from there.

Both ways work good, but the catch can way works great!

[cs daytona]

thanks. right after i made this thread, i started to see more posts on this situation (if i only read those 1st).

i was looking thru my jegs cat and found this jaz catch can with 2 3/8" nipples and a breather for like $50. didn't want the cheap ebay one because it had no filter and i would have to use one of the nipples to add the filter.

if i get rid of my airbox and slap a cone on it, could i get the same effect if i add a nipple to the pipe after the filter and run a vacuum source there? if so i could use that with the catch can.

thanks for the help

travis

[Tony Hanna]

if i get rid of my airbox and slap a cone on it, could i get the same effect if i add a nipple to the pipe after the filter and run a vacuum source there? if so i could use that with the catch can.

thanks for the help

travis

That should work fine. If you do it that way though, I'd still run a pcv valve setup like stock.

[Clay]

Venturian (heh, I think that's right)

Pretty darn close. Its venturi effect. I think Venturians were on star trek or something!

clay

[Tony Hanna]

Pretty darn close. Its venturi effect. I think Venturians were on star trek or something!

clay