It should be noted that the carb drip pans serve two functions: 1) to deflect venting carb fuel from falling directly on the exhaust pipes and 2) to somewhat insulate the carb bowls from heat radiated by the exhaust pipes.
It should be noted that the carb drip pans serve two functions: 1) to deflect venting carb fuel from falling directly on the exhaust pipes and 2) to somewhat insulate the carb bowls from heat radiated by the exhaust pipes.
Likely true, but in my 2 Model IVs, I had the drip pans on the first one and the pictured (previous post) variation on the second because I found with the nine years I had the drip pans, they made routine inspections and adjustment of the carburetor much more difficult as the float bowl couldn't be removed without separating the carburetor from the manifold as the drip pans I used were bolted to the manifold (Picture below). In the normal running of the engine - ground and flight - there was no apparent difference with and without. This latter was emphasized when I started flying with the local group of six as we began exploring California and the back country of Idaho. We flew together for 7 or 8 years and none of the other guys had drip pans.
Last edited by HighWing; 03-18-2020 at 10:50 AM.
I know this method will not meet the requirements of many of our "professional" builder/owners but for almost 900 hours now I have zip tied a piece of heat shield material purchased from a local auto supply store under the carbs. The auto performance folks use this to insulate starters etc from extreme engine heat. I attach it to the manifold and carb throat so it forms a "bag" under the carb. Keeps heat away and prevents fuel from running on the exhaust. Easily removed for servicing. I also run the vent tubes into the air filters.
I can post pics if anyone is interested!
Take care and be safe. I find the best way to self isolate is IN the HANGER or better yet IN the AIR!
Cheers
Don
Vixen C-FOXK 912UL IVO IFA
Don - I'm interested in the pictures - when you get time. Thanks, Darrel
See my build log at:http://www.mykitlog.com/lowandslow/
HighWing,
I really like your solution to this issue, to the point that I acquired the two little funnels after seeing your photo in March. It is now at the top of my short list and was pondering the use of clear drain lines from the funnels instead of the aluminum just for simplicity??
I see the zip tie holding the vent tube in the little funnel. Does the rigid aluminum tube keep the funnel in place or is it secured somehow next to the carb?
KF5 w/7 FWF
First flight, hopefully this year
Since the last post brought this subject back into the "New Posts" option, I thought I'd add a picture of what I finally decided to do. Basically I followed the lead of those that routed the line back into the air filter.
See my build log at:http://www.mykitlog.com/lowandslow/
Mine are done just like Delta W except I put the hole into the air filter as near the bottom as possible to get as much downslope to the vent line as possible. Been that way for about 900 hrs. The only downside I see to this arrangement is if your carb bowls start to overflow due to sinking floats or excessive vibration you will immediately get a super rich fuel mixture which would cause the engine to run very rough or even kill it. If this starts happening you will get immediate warning, probably on the ground during warm-up. Those engines with Rotax supplied airbox do essentially the same thing with the vent lines-run them into the airbox which feeds the carb intakes, so the risk must be quite small.
Jim Ott
Portland, OR
Kitfox SS7 flying
Rotax 912ULS