Puking oil out of this vent... Options

[jcwells]

Hey, all...

I took my teener out to a SCCA autocross event yesterday. Added 1/2 qt Brad Penn overfull to make sure that I had enough. I've got a tuna-can. Drove 100 miles to Pikes Peak International Raceway (PPIR), car running like a top. Made my first three runs, everything working great (I'm slow, not the car).

Third run complete, parked back on grid to get ready for fourth run. Look underneath, see a puddle of oil forming near the drivers side rear. Dang, what'd I break? Closer inspection shows that oil is dripping from above the tin, not below. Poking around inside, I see that one of the oil vent hoses has come loose, and the vent had puked out about 1/2 cup of oil onto the engine tin. I had some oil on my rear tire, so I bagged my last run, and headed home.

Here are some pics of what I've found:

I've got a Raby oil ventilation/recirculation box mounted on the firewall:


Here is the vent that the hose popped off of:


Here is the end of the hose that popped off:


Here is a picture of the hose:


Closer inspection of the hoses plumbed into the ventilation system shows that each of them are quite soft and gooey. It seems to me that these hoses are not up to the task of handling oil vapors. The hoses aren't more than two years old.

So, here are some questions that I'd like to ask:

• What type/spec of hose should I be using to handle this duty?
• What type of connectors/clamps can I use on new hoses to positively lock them on to the vent nipples?
• Vendor sources for these?

TIA for your help on this!

John

[Tom_T]

Simple answer is - do not overfill! (IMG:style_emoticons/default/biggrin.gif)

Type IV's & other VW & Porsche motors do NOT like to be overfilled & it causes all sorts of problems - including blowing out more expensive & hard-to-obtain parts, than your oil filler/breather tower!

Your "just to be safe" move actually caused the problem IMHO. (IMG:style_emoticons/default/dry.gif)
.. a better safety tactic is to just check & refill the oil as needed to be at the max level warm, between each run IMHO.

... BTW - that "loose hose" probably saved your butt from a more expensive break/damage, by allowing the excess pressure/volume to escape out it as the motor heated up & the oil expanded - as all stuff does when it heats, & shrinks when cool (which is why we check fluid levels in cars when warmed up).

The expansion factor & the fact that aircooled motors generally run a bit hotter than watercooled, is why the Type IVs & other aircooled VW & Porsche motors are so much more sensitive to overfilling.

Then since the oil is about half the cooling in an aircooled motor, when it burps the overfill - it usually burbs more than just the overage amount, and then you motor overheats due to the now too low oil level post burp!

[ChrisFoley]

Simple answer is - do not overfill! (IMG:style_emoticons/default/biggrin.gif)

I strongly disagree!
1/2 quart over filling a T4 engine has been accepted practice for AX and DE for as long as I've owned 914s. These engines are more sensitive to oil sloshing and uncovering the pickup than they are to "pressurizing the crankcase" or whatever from excess oil volume.
If there's enough pressure inside the rocker box to pop a hose you have more problems than a little extra oil in the sump. Crankcase pressure will not exceed 5" H2O - ever, in a healthy engine. That's only about 0.2 psi by the way.

You need fuel/oil rated hose not coolant hose.
Our breather kits include hose that works, as well as simple plastic hose clamps which are perfect for the application. We source them from McMaster-Carr.