Hi, You can mount and run this engine inverted. It has a 360 degree oil sump. You will however need to mount the carb right side up as there is a performance loss for some reason (can anyone clue me into why?). I ran mine for an hour today with no problems. I have had this engine mounted in my Fokker DVII 1/4 scale (mounted right side up) and now in my 1/4 scale Bud Nosen Aeronca (mounted inverted). I am useing a wood scimitar 20-8 @ 5200RPM and a APC scimitar 18-8 @ 6400RPM. Here are some pictures of my conversion of this engine and a movie of the DVII in flight with the Briggs. I havent had a chance to get the Aeronca on film yet but I will try tommorrow if anyone is interested.

Another note, you can replace the stock carb spacer (which is really wide and deep) with a spacer from a Ryobi 4-stroke engine. I purchased several of these from JacksSmallEngine.com for about 3.00 each. They are half the depth. You will need to trim some of the spacer at the ends to fit but it works just fine. I can post pictures of this also if anyone requests.

It is great to see more Briggs and Strattons out there.

http://media.putfile.com/Fokker-DVII-Sunny-Day

http://media.putfile.com/Fokker-in-flight