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:
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Here is the vent that the hose popped off of:
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Here is the end of the hose that popped off:
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Here is a picture of the hose:
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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

Simple answer is - do not overfill!

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.
.. 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!

PS - I just added your L80E's pic an your VIN listing, to my "inspiration photos file" for my 73 914S/914-2.0's resto!

I had the same issue on my very first track day. I overfilled, thinking I was saving a spun bearing. (my Chevy days were on my mind)

Wrong thing to do. I blew smoke and oil all over that nice track.

Don't listen to those guys, 1/2 qt overfill is FINE for an AX ...

Now to answer your question, i simply used the OEM cloth covered breather hose. Never had a problem with those.

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.

It can and will melt the heter hoses.
Use the ones Andy has pictured, and change them every year.
They break down right at that connection from the heat both internal, and from the heat of the head...

1/2 quart overfill is fine for an autox...when you turn hard corners, you fill up the heads with oil so your breather system needs to be really tight...

If this continues, you can replace the aluminum tube with a threaded brass fitting (similar to the ones on the tank you are using) and then use even better hoses.


Rich

Yeah, what they said...

personally, I would like to see threaded fittings at the head and at the tank...all threaded with a threaded host to match...

I chased this one for a few yeras...mine was a loose fitting at the head, not the hose...

It can get pretty ugly when that hose falls off...especially on the highway....

RIch

There's water hose, good for water, fuel hose, good for fuel, can be used for water in a pinch, and oil/vapor hose, used for oil, and for oil vapor. You have water hose, not good for oil. Replace it.

The Cap'n

nice to see another colorado guy around
wow those are healthy dyno numbers... (what altitude)

you should join up with our colorado gang some time.

was it a pca Autox?

brant

Hey, guys...

Sorry, was offline for a while...

Thanks for the collection of responses. Allow me to respond to a few;


I don't think that I had an overpressure issue. If you look at the end of the hose, it's degraded pretty bad from oil exposure. It *barely* fit on the vent connection at the head end at all. The breather hose from the oil fill tower to the box is in exactly the same shape. It pops off of the oil tower when I pull the dipstick to check the oil level! Sneeze on them hard, and they fall off.


This is what I had always read about T4 oil levels and autocrossing. This particular course had a number of high-g turns at high revs. The hoses originally (when I got the car last August) fit nice and tight. Not so much, now!


That's the plan. I'm soliciting advice for what to use, and how to connect it. SirAndy's suggestion of the OEM cloth covered hose sounds like the most obvious solution. I see that he is using standard hose clamps to connect. Any suggestions for vendor sources outside of the local neighborhood Porsche dealer?


Thanks! The dyno numbers come from Jake Raby's engine dyno at Aircooled Heaven. He did the testing of the engine for the previous owner, after the engine was built at DTM Engineering in Atlanta. The only credit that I can take is that I bought well!

I've done a few drives with some of the Colorado guys, including the recent one when the former Phoenix 914-6 GT (Jon Bovey) was in town. I've been to a handful of Ferg's Coffee and Cars events in Louisville too.

I've been doing the SCCA autox events for the last couple of seasons, and I try to do the local PCA events as well. I'm hoping the schedule is clear for the one this weekend at Front Range airport. But I gotta get these stupid hoses fixed first!


Cool! My car was local to your area with it's first few owners. It was originally sold by Bozzani Porsche/Audi in Monrovia. I have no idea if the dealer still exists.

Found that Jake Raby's TypeIV Store carries the OEM style breather hose in 12 mm, and for a good price. However, I wanted to get the breather box replumbed, and get the car cleaned up for the PCA autocross event this weekend. So, I found this oil-rated, heat resistant 1/2" hose at my local NAPA store, so I picked up 9 feet, and a pocketful of hose clamps. Here is the result:

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I'll give this a shakedown, and hopefully, it will be good to go for this Sunday's event.

Very nice John!
Glad to have met ya
We need to get together so I can check out your motor!
Plus I'm in Lakewood, not far from you.