Roger Lee Posted March 23, 2016 Report Share Posted March 23, 2016 Sorry not true. The new Corona pump can have some oil drips past the pump shaft seal. It is in the manual and has a value. A drip or ooze is normal, but some may not drip too. It isn't even across the board.It may have a drop or two, but not a steady drip. Where you put the vent tube can affect this. This was true with the old Pierberg and AC pumps, but not the Corona. I know this because I'm typing it while sitting in my updated Heavy Maint. Rotax class. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted March 23, 2016 Report Share Posted March 23, 2016 If your pump is leaking fuel, it's in a failed state - brand new or old. The ignition temperature of gasoline is about 495° F. Your exhaust will make a fine ignition source. True, but gasoline begins to vaporize at 89°F. A drop will flash off to vapor before it ever has a chance to ignite. You'd have to dump more gas onto the exhaust than could quickly evaporate. If this were not the case, you'd have a lot of CT engine fires, since the carbs are directly over the exhaust. That drip tray won't catch everything. I flew the 1400nm back from Arizona with both carb float bowls leaking a bit (they probably leaked on the way out, too), and never turned into a fireball or saw any evidence of combustion under the cowl. Link to comment Share on other sites More sharing options...
Roger Lee Posted March 23, 2016 Report Share Posted March 23, 2016 Andy, Check your fuel vaporization temp. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted March 23, 2016 Report Share Posted March 23, 2016 I looked it up, the site I read said it starts at 89 and goes up faster from there. Even if wrong a bit, the principle stands. Link to comment Share on other sites More sharing options...
Roger Lee Posted March 25, 2016 Report Share Posted March 25, 2016 Andy, Here is gasoline MSDS sheet. The vaporization starting point for gasoline is -45F. Gas won't burn below this point as it does not produce any vapor. You must have vapors for gas to burn. Anything above that and gas will produce a vapor and can burn. So at your 89F gas is extremely flammable. Vapor concentration needs to be between 1.4% and 7.6%. Below 1.4% it is too lean a mixture to burn and above 7.6% it is too rich and needs more oxygen. In almost all places in the US and almost anytime of year gasoline will be ignitable because most places aren't below -45F. http://www.archgh.org/default/RiskMgmt/MSDS-Gasoline.pdf Link to comment Share on other sites More sharing options...
Roger Lee Posted March 25, 2016 Report Share Posted March 25, 2016 Please look at my above post about dripping from the Corona fuel pump. I original wrote fuel and it should have been oil. I was in class and thinking fuel pump and wrote fuel. It is oil that leaks around the fuel pump shaft past its seal. Sorry for the mislead. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted March 25, 2016 Report Share Posted March 25, 2016 Andy, Here is gasoline MSDS sheet. The vaporization starting point for gasoline is -45F. Gas won't burn below this point as it does not produce any vapor. You must have vapors for gas to burn. Anything above that and gas will produce a vapor and can burn. So at your 89F gas is extremely flammable. Vapor concentration needs to be between 1.4% and 7.6%. Below 1.4% it is too lean a mixture to burn and above 7.6% it is too rich and needs more oxygen. In almost all places in the US and almost anytime of year gasoline will be ignitable because most places aren't below -45F. http://www.archgh.org/default/RiskMgmt/MSDS-Gasoline.pdf To the point of my post...do you think a drip of gas on to the exhaust of a running engine would ignite? Link to comment Share on other sites More sharing options...
Doug G. Posted March 25, 2016 Report Share Posted March 25, 2016 That would depend on the flash point, you can boil gasoline as long as you have no spark to ignite it. (Not recommend, however.) Link to comment Share on other sites More sharing options...
FlyingMonkey Posted March 25, 2016 Report Share Posted March 25, 2016 That would depend on the flash point, you can boil gasoline as long as you have no spark to ignite it. (Not recommend, however.) That was my point, but the claim was stated that at some temp between 480° and 550° the fuel would ignite without flame or spark. Link to comment Share on other sites More sharing options...
Anticept Posted March 25, 2016 Report Share Posted March 25, 2016 The autoignition point is 536F. The flash point is -45F. The exhausts are much hotter than either. Using my heat gun, I was clocking over 800 degrees at higher power settings... and that's with cowling off. Most definitely enough to ignite. Link to comment Share on other sites More sharing options...
Roger Lee Posted March 25, 2016 Report Share Posted March 25, 2016 Look at your EGT temps in flight and tell me what you think the exhaust metal temps are right out of the head and right under each carb. I do agree that it may take the perfect storm to ignite and a drop will more likely evap, but in flight fires have and will continue to happen. Why play Russian Roulette if there is absolutely no need. Link to comment Share on other sites More sharing options...
Doug G. Posted March 26, 2016 Report Share Posted March 26, 2016 Yeah, can't say I am fond of any fluids leading under my cowl. I would much prefer Dex to fuel or oil though. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted March 26, 2016 Report Share Posted March 26, 2016 Agreed, I'm not saying leaks are cool. Just that small leaks of various fluids, even gasoline, are rarely dangerous. Rarely doesn't mean never, of course. Link to comment Share on other sites More sharing options...
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