• Welcome aboard HomebuiltAirplanes.com, your destination for connecting with a thriving community of more than 10,000 active members, all passionate about home-built aviation. Dive into our comprehensive repository of knowledge, exchange technical insights, arrange get-togethers, and trade aircrafts/parts with like-minded enthusiasts. Unearth a wide-ranging collection of general and kit plane aviation subjects, enriched with engaging imagery, in-depth technical manuals, and rare archives.

    For a nominal fee of $99.99/year or $12.99/month, you can immerse yourself in this dynamic community and unparalleled treasure-trove of aviation knowledge.

    Embark on your journey now!

    Click Here to Become a Premium Member and Experience Homebuilt Airplanes to the Fullest!

VW Crankcase vent

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Pops

Well-Known Member
Joined
Jan 1, 2013
Messages
13,222
Location
USA.
I was having a small problem with a oil leak around the prop hub seal. The area around the seal would have an oil film and after flying a few hours a light oil mist would be on the windshield. I built a reed valve like the 1/2 VW boys use to run a neg pressure in the cut case VW. Made from steel feeler gauge material maybe .005. Mounted it in the alum box bolted to the gen stand location with a thermos bottle sealed plug to add oil. The oil goes under the reel valve. With running a vacuum in the crankcase, you have no oil leaks and the prop hub area stays dry. I did like the VW company and ran the 3/8" breather line to the intake of the carb. I have a fiberglass tube that runs from the carb intake to the airfilter box. Drilled a hole about 2" in front of the carb intake and cut a bevel on the end facing the carb and epoxyed to the FG tube. Now with running a vacuum in the crankcase, I have no oil leaks. The area around the prop oil seal stays dry. You also will get a small increase in power by the crank running in a vacuum.

Dan
 

Attachments

  • DSCF0007 (2).jpg
    DSCF0007 (2).jpg
    79.8 KB · Views: 113
Back
Top