Universal Crankcase Evacuation System

• Exhaust-scavenged design uses exhaust flow to pull crankcase vacuum

• Two breathers mount in 1.25" valve cover openings, hose-linked to exhaust

• Weld-on bungs install in the exhaust collector; check valves prevent backflow

• Not for use with O2 sensor–equipped exhaust or vehicles running a muffler

The Universal Crankcase Evacuation System uses exhaust flow to pull a vacuum on the crankcase, rather than simply venting to atmosphere. Two chrome-finished steel breathers mount into 1.25" valve cover openings using the included grommets, and connect via 5/8" ID hose to two weld-on threaded bungs installed in the exhaust — typically at the collector. As exhaust gases pass the bungs, they draw crankcase gases through the system, and the included one-way check valves prevent exhaust gases from flowing back into the crankcase.

This system is designed for open exhaust or header-and-collector setups without a muffler, and is not intended for vehicles equipped with oxygen sensors or a muffler in the exhaust path where the bungs are installed. Hoses are not included — only the hose barb fittings on the breathers and bungs.

This kit is commonly used on universal hot rod, muscle car, truck, and performance builds, including Chevrolet, Ford, Mopar, and GM V8 applications with compatible valve cover openings and header/collector exhaust systems. Verify valve cover hole size, exhaust bung placement, and hose routing before installation.

Kit Contents
(2) chrome steel valve cover breathers, (2) breather grommets sized for 1.25" valve cover openings, (2) weld-on threaded nipples for exhaust installation, (2) one-way check valves. Hoses are not included.

How It Works
The two breathers mount in the valve covers; the two weld-on bungs are welded into the exhaust, typically at the collector. Exhaust flow past the bungs draws crankcase gases through 5/8" ID hose connecting the breathers to the bungs, and the check valves prevent exhaust gases from reaching the crankcase.

How does this crankcase evacuation system work?
It uses exhaust flow to pull a vacuum on the crankcase. Two weld-on bungs are installed in the exhaust, typically at the collector, and connected by hose to two breathers mounted in the valve covers. Exhaust flow past the bungs draws crankcase gases through the system.

Can I use this with an exhaust system that has oxygen sensors?
No. This system is not intended for use with oxygen sensor–equipped exhaust systems at the bung installation point.

Can I use this with a muffler?
No. This system is not intended for use on vehicles running a muffler in the exhaust path where the bungs are installed — it's designed for open exhaust or header/collector setups.

What size valve cover opening do the breathers need?
The included grommets are sized for a 1.25" valve cover opening.

Where do the weld-on bungs get installed?
The bungs are typically welded into the exhaust collector.

What do the check valves do?
The one-way check valves prevent exhaust gases from flowing back into the crankcase through the system.

Are hoses included?
No. Hoses are not included — only the hose barb fittings on the breathers and bungs. 5/8" ID hose is required.

Does this system affect emissions compliance?
This product does not affect vehicle emissions and is not subject to emissions compliance regulations.