Jim Peace Posted February 21, 2016 Report Share Posted February 21, 2016 (edited) Strained both left and right tanks and color was normal. Strained the fuel selector and the darker blue liquid came out. Looked like tidy bowl. Took three samples to be normal. Picture enclosed. Has anyone seen the dye get this dark? And why? plane was not flown in 12 days. But that is normal time for me. Never seen it before Edited February 22, 2016 by Jim Peace Quote Link to comment Share on other sites More sharing options...
Seth Posted February 21, 2016 Report Share Posted February 21, 2016 That does not look normal. But I have no knowledge if it is okay or not. If it were me . . . 1. Sump until usual color 2. If lots of sumping with no change, I'd ask a professional for assistance before starting my engine. -Seth Quote Link to comment Share on other sites More sharing options...
carusoam Posted February 21, 2016 Report Share Posted February 21, 2016 That would be typical of a few gallons of gas evaporating out of an open container. i have not collected anything out of the gascolator, yet... what is the volume of the tubes and gascolator? there are a couple of places that fuel can evaporate and concentrate that blue dye, but that is mostly after the carburetor. Best regards, -a- Quote Link to comment Share on other sites More sharing options...
N601RX Posted February 21, 2016 Report Share Posted February 21, 2016 I saw something similar to that a couple of years ago, except the fuel was purple. After removing the bowl and looking in the screen their was some purple debree in the screen. It was being slowly dissolved by the fuel and coloring it. It didn't come from the plane, it must have been something that got in while fueling. Quote Link to comment Share on other sites More sharing options...
LANCECASPER Posted February 21, 2016 Report Share Posted February 21, 2016 1 hour ago, Jim Peace said: Strained both left and right tanks and color was normal. Strained the fuel selector and the darker blue liquid came out. Looked like tidy bowl. Took three samples to be normal. Picture enclosed. Has anyone seen the die get this dark? And why? plane was not flown in 12 days. But that is normal time for me. Never seen it before I would look in the tank to make sure the Tidy Bowl man wasn't down there someplace. Quote Link to comment Share on other sites More sharing options...
takair Posted February 21, 2016 Report Share Posted February 21, 2016 Jim, I've never seen that either. One has to wonder what that does to octane rating and burn. Just curious, regarding sumping the gascolator and collecting in the sump cup, how do you do that? Are you in Florida where you can't deposite on ground? Quote Link to comment Share on other sites More sharing options...
Jim Peace Posted February 21, 2016 Author Report Share Posted February 21, 2016 (edited) 15 minutes ago, takair said: Jim, Just curious, regarding sumping the gascolator and collecting in the sump cup, how do you do that? Are you in Florida where you can't deposite on ground? I have a 1964 M20C. It has a quick drain almost like a tank. No ring to pull from inside. This was in Van Nuys and depositing it on the ground actually improves the place.... Edited February 21, 2016 by Jim Peace Quote Link to comment Share on other sites More sharing options...
Jim Peace Posted February 21, 2016 Author Report Share Posted February 21, 2016 2 hours ago, carusoam said: there are a couple of places that fuel can evaporate and concentrate that blue dye, but that is mostly after the carburetor. Best regards, -a- Well there must be a place for it to happen near the selector.....I don't see how this could occur any other way.....must have been evaporation Quote Link to comment Share on other sites More sharing options...
Mooneymite Posted February 21, 2016 Report Share Posted February 21, 2016 That's weird. How long had it been since the last sumping? Quote Link to comment Share on other sites More sharing options...
co2bruce Posted February 21, 2016 Report Share Posted February 21, 2016 Had some recent work done on fuel transducer. The part was out of the plane for a week or so and when we put it all back together and ran the fuel pump the fuel we collected had a very dark blue color. It's dye. I would continue to sump the selector until color is normal. I be you haven't summed it in a long time. ****** I'm not a mechanic just a PP. I would ask a local mechanic just to be sure***** Quote Link to comment Share on other sites More sharing options...
mike_elliott Posted February 21, 2016 Report Share Posted February 21, 2016 I have seen it before when there was a very slight weep of the quick drain (actually one of the rivets that secure the quick drain socket) and it hadn't been sumped in a couple of weeks. Quote Link to comment Share on other sites More sharing options...
Jim Peace Posted February 21, 2016 Author Report Share Posted February 21, 2016 2 hours ago, Mooneymite said: That's weird. How long had it been since the last sumping? 12 days......but I go two weeks all the time without flying.... Quote Link to comment Share on other sites More sharing options...
Jim Peace Posted February 21, 2016 Author Report Share Posted February 21, 2016 47 minutes ago, mike_elliott said: I have seen it before when there was a very slight weep of the quick drain (actually one of the rivets that secure the quick drain socket) and it hadn't been sumped in a couple of weeks. I will pass this along to my mechanic thank you Quote Link to comment Share on other sites More sharing options...
DonMuncy Posted February 21, 2016 Report Share Posted February 21, 2016 13 hours ago, takair said: Jim, I've never seen that either. One has to wonder what that does to octane rating and burn. Just curious, regarding sumping the gascolator and collecting in the sump cup, how do you do that? Are you in Florida where you can't deposite on ground? I have an oil catch container I slide under the center gascolator and pull the ring. I can then look at the gas and make sure no water is there. My catch pan has a pour nozzle on it where I could recapture the fuel for my tug, but I usually just let it evaporate. Probably not any better for the atmosphere than pouring it on the ground. Quote Link to comment Share on other sites More sharing options...
Hank Posted February 21, 2016 Report Share Posted February 21, 2016 Ah. You're collecting fuel in a catch pan, letting it evaporate, then adding more fuel. The dye doesn't evaporate, so you're concentrating blue dye over time. When you add more fuel, it will absorb the previous dye. If your catch pan is as crooked as the one I catch oil from my car, the fuel probably puddles in different places, and runs through or around the previous dye spots when you pour it out. Time between deposits can also have an effect. If a pool of partially evaporated fuel is still sitting there when you sample again, it will mix more readily than other dried dye will absorb while simply running across it. That's my theory, and I'm sticking to it! Quote Link to comment Share on other sites More sharing options...
DonMuncy Posted February 21, 2016 Report Share Posted February 21, 2016 Sorry for veering off topic. I have only been concerned about water in the fuel. Quote Link to comment Share on other sites More sharing options...
Marauder Posted February 21, 2016 Report Share Posted February 21, 2016 Strained both left and right tanks and color was normal. Strained the fuel selector and the darker blue liquid came out. Looked like tidy bowl. Took three samples to be normal. Picture enclosed. Has anyone seen the die get this dark? And why? plane was not flown in 12 days. But that is normal time for me. Never seen it before Do you know if they have old supercharged radial war birds on the field? There was an AVGas 115 produced that was a primary fuel. The color is supposed to be purple. I think they still make it available. I saw it once at an air show. Sent from my iPad using Tapatalk Quote Link to comment Share on other sites More sharing options...
carusoam Posted February 22, 2016 Report Share Posted February 22, 2016 Aside from leaving all the dye behind... The first part of the fuel to possibly evaporate and leave the system is the lighter more volatile part of the fuel. The light part is the part that is best for evaporating and burning when trying to cold start the engine. If this is a normal behavior of sitting for a few weeks, it may make more sense to catch and look at what comes out of the gascolator. When extra dark, bleed until normal. Toss or put back in the tank with the other 51 gallons...(I would prefer toss) The other half of the question is the octane rating. The octane rating is inversely related to the volatility of the gasoline. higher octane gasoline has lower volatility. a higher concentration of blue dye, is not going to naturally turn into the purple dye used for the intentionally higher octane fuel. In case I get misunderstood more than usual... Fun engineering stuff... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.