FrontEngineDragsters.Org Forum

Technical => Spud Miller's Cave => Topic started by: BK on September 10, 2018, 05:29:35 AM

Title: Fuel Contamination
Post by: BK on September 10, 2018, 05:29:35 AM
Spud,
 At what point would you think water in Methonal would affect performance.
 My car slowed a tenth in the 1/8th and was stuttering just before the finish line.
 It seemed fuel starved but everything looks good, Unless pump went bad in one run or line from tank is collapsing inside.
 I used fuel from a different source just before this started.
Title: Re: Fuel Contamination
Post by: gregm784 on September 10, 2018, 10:36:56 AM
Have you floated it to see if it is contaminated?
Title: Re: Fuel Contamination
Post by: BK on September 10, 2018, 01:32:10 PM
Not when I asked the question but I have it now.
I got a reading of .800 at 57 deg.
If my math is correct it comes out to 96.49% pure.
Or 3.51 percent of probably water. Is that enough water to make a noticeable difference?
Title: Re: Fuel Contamination
Post by: Spud Miller on September 11, 2018, 10:30:17 AM

 Yuck...anything with more than a percent or two and I wouldn't use it.

 When it gets moisture in it, it turns acidic and sets up a chemical reaction that can etch your fittings and ruin stuff quickly.

 Spud

Title: Re: Fuel Contamination
Post by: THE FRENCHTOWN FLYER on September 11, 2018, 02:02:32 PM
So, what is 96% alcohol good for? Besides starting trash fires.
Title: Re: Fuel Contamination
Post by: Spud Miller on September 11, 2018, 02:50:57 PM

 Killing weeds.

Title: Re: Fuel Contamination
Post by: BK on September 11, 2018, 05:42:50 PM
Thanks Spud.
Looks like I have 10 gallons of weed killer.
Title: Re: Fuel Contamination
Post by: JrFuel Hayden on September 12, 2018, 11:59:43 AM
Since NHRA Heritage JrFuel rules are ONLY Pure Alky is allowed, we are very good about alway clsing our fuel jugs after we fill our tank, because alky draws water.
I've heard cases of a jug left open can fill up the jug with water, depending on Humidity / grains of water in the air.
In the early 70's I helped an injected alky funny car and we used a tall plastic tube with what looked like moth balls to filter the alky before use to take the water out.
I have not seen those filers in years. But yes a engine can detonate with water in the fuel.
BTW Heritage JF is sponsored by ERC, race fuels and even Scott Parks has said ERC is the cleannest alky he has ever used, based on no crap in the fuel tanks after use. They double filter the fuel and then put it super cleaned barrels.
Of course we filter our fuel going into the fuel tank. And take apart & clean our fuel system after each race event. It's the first thing we do after getting back to the shop. Never had any pluged lines, nozzels, jets.
Cheers
Title: Re: Fuel Contamination
Post by: opa1 on September 12, 2018, 03:02:54 PM
What all do you do when you clean the system? I'm having to park my car for a while due to a accident(me not the car). I took the inlet hose to the metering valve off and blew air through the valve and nozzles to get the fuel out. Should I pull the supply hose from the tank to the pump and clean this out too? Returns too?

Mark
Title: Re: Fuel Contamination
Post by: Roger on September 12, 2018, 03:44:00 PM
Check out this previous post on cleaning the system between races. Good information there, alcohol and aluminum do NOT get along worth a darn.

http://www.frontenginedragsters.org/forum/index.php/topic,2560.msg18402.html#msg18402
Title: Re: Fuel Contamination
Post by: opa1 on September 12, 2018, 04:13:11 PM
Thanks Roger, Looks like my son has some work to do. :)
Title: Re: Fuel Contamination
Post by: BK on September 12, 2018, 07:31:51 PM
I knew better but bought 5 gallons out of a large tank at the track.
It looks like the bigger problem was the check valve in my primer nozzle.
Its plumbed into the distribution block and found it was leaking just blowing through it.
I couldn't see any trash in it. Cleaned it and it still wouldn't hold.
Ended up putting a Nitrous solenoid in line to stop the bleed back.