Modify tank rib for faster fuelling?

jimgreen · #1 08-01-2016, 06:06 PM

Talked recently to someone who had modified the most outboard internal ribs with larger holes to speed up fuelling. There are only two small holes at the top of the ribs.
What side effects would this have?
Any comments from builders who have done this?

SHIPCHIEF · #2 08-01-2016, 10:03 PM

I agree that fueling with the stock arrangement is slow if you want a full tank.
However, I have started flying aerobatics, and I can fly the whole 2016 IAC Primary sequence without the engine missing a beat with less than a half tank of fuel.
I do have AIrflow fuel injection, but I don't have a flop tube nor an inverted oil system.
So the small rib vents might be helpful keeping the fuel around the pickup?

jimgreen · #3 08-05-2016, 10:30 AM

I like to top right up every few fills to check on the totaliser.
I wondered about opening up holes in the second to last rib (out board) which I believe might be the main restriction to faster fuelling.
I doesn't seem that would have much effect on fuel sloshing about with lower fuel levels, but it would be great to get feedback from anyone who has tried that.
BTW is there any negative G involved in the IAC Primary routine?