Corn in the Comet

[Jim Comet]

Well with the price of race gas going over $10 bucks a gallon, I decided to try E85 in my 12.9 to 1 comp. 416FE. Last year I bought a custom E85 calibrated carb from Pro Systems. When I tried to run it with my 8an lines and Holley black pump, it kept going lean after launch. I put in the biggest jets I had at the time and ran 98 fronts with a power valve and 99s rear with no power valve but it would still go lean after launch. So, over the winter I upgraded to a Magnafuel Quickstar 300 pump and 10an lines front to rear. Pro systems said I should up my fuel pressure so I bumped up to 9psi. This helped but didn't fix it. I then upgraded from 120 needle and seats to BLP dual flow 140's, added a 4 window power valve and upped my jetting to 102 front and 106 rear. I was then able to lower my fuel pressure to 7psi. This was the ticket and I can now make full passes with my afr reading 80 on the lambda scale. There is no sign of detonation on the plugs and this is using pump $2.50 E85 that tests out to E80. The car is now running 10.70's @126mph. Jim

[6667fan]

Sound like you weren’t going down without a fight. Congrats on sticking with it. Must have taken several trips to track and a number of passes.
 I’m not familiar with running that fuel. Quite a balancing act to give it what sounds like a lot of fuel volume and then metering it with the right amount of pressure.

what’s next?

[Rory428]

Curious how much he special carb, new fuel pump, and other mods cost? Compared to a couple of barrels of Sunoco or VP race gas. I sure wish race gas only cost $10. a gallon here in Canada. I usually get 2 seasons from a 55 gallon drum, usually used VP C12, my las barrel was Sunoco Supreme, as it was a bit cheaper than the VP (at "only $1550. for a 55 gallon barrel!) That worked out to $28. Canadian per US Gallon. I did a back to back to back test between the Sunoco Supreme, Sunoco Standard, and  LL 110 "Av Gas", (my local dragstrip is a municipal airport between race weekends), and my Fairmont ran exactly the same with all 3 fuels on the same rack, on the same day. Guess I will be running the AV gas once I use up all the Sunoco. We don`t`have E85 readily available here, some guys do run Alcohol/Methanol, but that requires a new carb (or fuel injection), fuel pump, fuel lines, and draining the fuel system between race weekends, and lubricating the system . Does E85 require similar maintenance ? More work than I wan to deal with.

[Jim Comet]

I have about $2000 dollars in the complete setup. That includes the carb, fuel pump, regulator and new 10an fittings and lines front to rear. That is about 2 years worth of fuel if I was buying race gas here in Minnesota. I can buy E85 anywhere in Minnesota for $2.50 a gallon. It is a long term investment but now I don't have to buy and store barrels of race gas. As far as maintenance goes, I add Lucas oil E85 stabilizer to the tank if the car will sit. If the car is going to sit for more than a couple weeks I drain my carb bowls. I have a plastic fuel cell and use aluminum lines with Aeroquip Starlite hose and have had no issues so far. As I understand, E85 isn't corrosive like Methanol but does hold moisture hence the E85 stabilizer when the car is going to sit. Time will tell. Jim

[cjshaker]

Those are some BIG jets. I'm assuming it takes roughly twice as much fuel as regular race gas also? I'm sure it's still probably cheaper in the end. And cutting the same ET with 60 less horsepower and 600 less RPM is a win/win deal that will definitely make life easier on the engine.

[Jim Comet]

It takes a little over 1 gallon of fuel per 1/4 mile pass. That includes idle time in staging, the burnout, making the pass, shut down and returning to the pits. I would guess mileage to be about 1 mile per gallon. Jim

[mike7570]

Rory 428, how long does the fuel last in the drum? Would it continue to pass NHRA fuel check?
I’m currently using C25 (didn’t notice any difference from C12). I have been purchasing 5gallon cans at the track for just under $100 (US🙂) I get about 1 run per gallon in my stocker also.
Fred Moreno and a few other stock racers suggested using the C25.

[allrightmike]

It takes a little over 1 gallon of fuel per 1/4 mile pass. That includes idle time in staging, the burnout, making the pass, shut down and returning to the pits. I would guess mileage to be about 1 mile per gallon. Jim

Have you experienced noticeable oil dilution from the alcohol?

[Jim Comet]

I run Amsoil Dominator and have not seen that but, I do run a pair of Jays clear valve covers and was shocked at the amount of moisture in the motor after start up after is sits for a week. I am now installing an evap system to pull vacuum out and hopefully avoid the milk in the valve covers. Just to reiterate the oil on the dipstick has always been clear and looks moisture free. Jim

[1967 XR7 GT]

       Heads Up for everyone.
AV fuel has deicing agents for the cold at higher altitudes, and can be an issue for our high compression, big buck motors.

AV motors are low compression, and run in the 3,500 to 3,800 rpm range.



[ :)quote author=Rory428 link=topic=12785.msg137240#msg137240 date=1748565072]
Curious how much he special carb, new fuel pump, and other mods cost? Compared to a couple of barrels of Sunoco or VP race gas. I sure wish race gas only cost $10. a gallon here in Canada. I usually get 2 seasons from a 55 gallon drum, usually used VP C12, my las barrel was Sunoco Supreme, as it was a bit cheaper than the VP (at "only $1550. for a 55 gallon barrel!) That worked out to $28. Canadian per US Gallon. I did a back to back to back test between the Sunoco Supreme, Sunoco Standard, and  LL 110 "Av Gas", (my local dragstrip is a municipal airport between race weekends), and my Fairmont ran exactly the same with all 3 fuels on the same rack, on the same day. Guess I will be running the AV gas once I use up all the Sunoco. We don`t`have E85 readily available here, some guys do run Alcohol/Methanol, but that requires a new carb (or fuel injection), fuel pump, fuel lines, and draining the fuel system between race weekends, and lubricating the system . Does E85 require similar maintenance ? More work than I wan to deal with.
[/quote]

[Rory428]

Rory 428, how long does the fuel last in the drum? Would it continue to pass NHRA fuel check?
I’m currently using C25 (didn’t notice any difference from C12). I have been purchasing 5gallon cans at the track for just under $100 (US🙂) I get about 1 run per gallon in my stocker also.
Fred Moreno and a few other stock racers suggested using the C25.

I have had VP C12 that was 2 to 3 years old, that ran just as good as "fresh" C12 did, but at times, it would sometimes be borderline at NHRA fuel check. At the end of he racing season, I would dump whatever C12 that I had in plastic fuel jugs, or left in the cell/tank, back into he 55 gallon drum for the winter. A buddy with a Stocker had C12 that spent 3 years in his sock gas tank and still passed fuel check, but on the other hand, I had some C12 that that I bought a the Seattle National event, at he VP trailer in the pits, in 2010, and that same gas, one week later at the Sonoma California National event, tested borderline at fuel check. Go figure. When I lived on the West Coast of Canada, buying C12 by the 5 gallon pail, was considerably more expensive per gallon, as buying a 55 gallon drum. Plus the convenience of having a drum of fuel at home in handy. I prefered buying race gas at NHRA National events, and some LODRS divisional races, and having it pumped into my own jugs, but that was no always possible, especially at regular bracket races, as for the past several years that I raced at some tracks, race gas was not sold trackside.

[Rory428]

       Heads Up for everyone.
AV fuel has deicing agents for the cold at higher altitudes, and can be an issue for our high compression, big buck motors.

AV motors are low compression, and run in the 3,500 to 3,800 rpm range.



[ :)quote author=Rory428 link=topic=12785.msg137240#msg137240 date=1748565072]
Curious how much he special carb, new fuel pump, and other mods cost? Compared to a couple of barrels of Sunoco or VP race gas. I sure wish race gas only cost $10. a gallon here in Canada. I usually get 2 seasons from a 55 gallon drum, usually used VP C12, my las barrel was Sunoco Supreme, as it was a bit cheaper than the VP (at "only $1550. for a 55 gallon barrel!) That worked out to $28. Canadian per US Gallon. I did a back to back to back test between the Sunoco Supreme, Sunoco Standard, and  LL 110 "Av Gas", (my local dragstrip is a municipal airport between race weekends), and my Fairmont ran exactly the same with all 3 fuels on the same rack, on the same day. Guess I will be running the AV gas once I use up all the Sunoco. We don`t`have E85 readily available here, some guys do run Alcohol/Methanol, but that requires a new carb (or fuel injection), fuel pump, fuel lines, and draining the fuel system between race weekends, and lubricating the system . Does E85 require similar maintenance ? More work than I wan to deal with.

[/quote]
While I had heard similar stories about AV Gas in the past, and stopped using it years ago, I changed my mind a few years ago, when at my local track, which is also an airport, and sells LL110 AV Gas at a pump. My pit spot is not far from the AV Gas pump, and I was surprised when I saw some very well respected Stock and Super Stock racers buying AV Gas, and having it pumped into their own jugs. I asked one of them, who is a very highly regarded race engine builder, machinist, and Dyno operator, who at that time, was racing his 427 L88 Corvette in SS/AA, and 69 ZL1 Camaro in SS/BA, both cars ran well into the 8 second range, and approaching 9000 RPM. When I asked him if he was mixing the AV Gas with actual "race gas", or doing some considerable engine tuning changes, he said no. At a NHRA National event, or divisional race, where fuel check is done, he ran C16, but at the local Sock Super Sock association races, he ran the much cheaper AV Gas. Both of his cars, and many engines that his shop builds for Stock and Super Stock racers , are or have been NHRA National Record Holders, and have won Class and eliminator races, so he has pretty strong credentials. Some of the other racers buying AV Gas that day include a 71 Chevelle LS6 that runs 9.2 ETs in SS/DA, and a 69 Camaro 396/375 that runs high 9s in B/SA. So I figured if the AV Gas is good enough for those guys, and their big dollar, max effort Sock and Super Stock engines, I have no qualms about running it in my 7000 RPM, 10.5 compression 347 SB Ford that runs 10.0s.

[427mach1]

AV gas does not have any deicing additives; that is an old wives tale that refuses to die.  Many years ago, I called Phillips Petroleum and spoke to Clayton Reasor (don't know why I still remember his name after this long) about their racing fuels.  He told me all about the 5 or 6 variations they offered; lead levels, octane levels, etc.  I then asked him specifically if there were any deicing additives or anything else in their AV gas that would cause problems in an automotive engine.  He said no, and as long as you're not getting pre-ignition, it would be safe to run.  Something else to consider is the octane rating method.  Automotive fuels are rated using the average of the research and motor octane levels.  100LL uses the lower of the two.  If it were rated using (R+M)/2, it would be around 105 - 107.

[428kidd]

I ran Av LL for years in all my stuff never one hint of a issue. Id be running it now if it hadn't gotten hard to get.