Auto-X problem - with Video!, I have a crankcase pressure issue |
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Auto-X problem - with Video!, I have a crankcase pressure issue |
Tom Perso |
Aug 9 2004, 07:24 AM
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#1
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Crazy from the Cold... Group: Members Posts: 647 Joined: 8-August 03 From: Kalamazoo, MI Member No.: 1,003 |
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 |
Brad Roberts |
Aug 9 2004, 08:59 AM
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#2
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914 Freak! Group: Members Posts: 19,148 Joined: 23-December 02 Member No.: 8 Region Association: None |
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 |
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