Auto-X problem - with Video!, I have a crankcase pressure issue Options

[Tom Perso]

Hey Guys,

I took the 914 out this weekend for my first Auto-X. It's a 74 slantnose with stock suspension, a stock front swaybar, and Yokohama A-008R's on Empi rims (they are just the Auto-X rims).

The motor is a Raby-inspired 2270 "C" motor (with too large intake valves).

I had some issues at high RPMS with blowing oil out of the valve cover gaskets and pushrod tube seals. I only had one vent on the case (at the oil filler) and I determined that I needed a little more venting due to the higher displacement and higher RPM's.

I had a second set of valve covers, so I drilled and added a 1/2" barbed connection that sits above the retaining bail (on each side). I vented each valve cover up to the air filter cover for the Webers.

I took the car out for a little spin and no more blowing oil! I figured I had success...


So, fast forward to the event. I take off around the course and at the first long sweeper and I bumped 7000rpm. I really needed second gear for where I was at, so I figured I'd get it right the second time around...

So, after that long sweeper, I start blowing oil out of the exhaust - badly. But it didnt last for long. I still had good pressure, so I dropped down to second gear and limped around the rest of the course.

Around the last sweeper I blew some more oil and then the motor almost quit at the ending gate.

To make a long story short, I sucked more oil into the carbs and finally fouled the plugs.

Here's the pathetic video...

http://www.qtm.net/~persot/914_smoke-1.wmv

So, should an external breather box help the situation or did I got wrong with adding the vents to the valve covers?

Any ideas/suggestions would be appreciated!

Thanks,
Tom

[Trekkor]

Andy showed us a picture of his set-up recently.

Use a sponge filled remote breather box.
The oil vapor will liquify and run back down into the valve covers.

You're almost there! (IMG:style_emoticons/default/driving.gif)

KT

[machina]

Here's the pathetic video...

I really liked the video clip, especially the enthusiastic commentary. (IMG:style_emoticons/default/laugh.gif)

dr

[Tom Perso]

My wife is very supportive (and understanding...)

LOL

Yeah, that's normal!!!! Hahah, she kills me!

Tom

[rhodyguy]

tom, i remember the vid of when you got your engine in the bug. i think jake mentioned that the cb style box was inadequate for the 2270, they can't handle the internal pressures created in the engine. some TIME ago brad told me to get a JAX bottle. my searches have been fruitless. cb doesn't list it on their website. i think rich should stock about ten of them at hph. i would get one tomorrow. man, i'm used to much longer ax courses. what size valves should you have installed in your heads?

kevin

[Brad Roberts]

Summitracing.com

and it was JAZ.

Tom, it is worthless trying to vent to the carbs. The only way that works is if you have a common intake plenum like the stock 2.0 engines with injection.

We run a catch can in the trunk and route it through one of the plastic latch cups in the trunk firewall. The best you can do is catch it... worry about draining it later. Make sure you check it every so often or figure out a way for it to drain back into the engine..


B

[Tom Perso]

Thanks for the tips... It's been a PIA recently to get this thing vented correctly.

The course was quite short - it's more of a "fun run" - the venue is quite small, so it's not really quick.

I have 48mm intake valves - Jake recommends 44mm.

Regardless, I think the car has some potential, I just need to get it tidied up and we'll be all set.

Later,
Tom

[Tom Perso]

Here is the link to a JAZ can...

http://cjsupra.kendra.com/PCV-Can.html

Later,
Tom

[bernbomb914]

Tom the vents for the intake are reverse of what you think they blow in at the heads and out at the oil filler. look at SIR ANDYS pics from a old post to see the way to go.

Bernie

[Jake Raby]

Tom, the deves rings you are using are not best for Auto-X.. they are great for the street and spirited driving, but in Auto X they hurt a bit with issues like this.

Yes, you must vent to the carbs somehow to get any success with a good breather system. I have a CSP breather box in the rear trunk that takes care of mine, and she is good for 8K revs.

[Tom Perso]

Thanks Jake,

I know the Deves rings are a little strange, but I didn't know I'd have problems like this with em.

Thanks for the tips everyone, I'll get it squared away and start with another Auto-X and tear it up!

Later,
Tom