Flex Fuel for a 3V

[blacksheep-1]

The flame front speeds were an answer to a question I asked the Pro Commander folks. I asked why they didn't adjust timing (only fuel injector pulse width), and the answer I got was flame front speeds. It made sense so I pondered on it for a while.

The following is from google, so until I get a little more solid reference, I'll just put this out there.

Flame tomography showed that at radii between 8–12 mm, ethanol was burning the fastest, followed by butanol, iso-octane and gasoline. The associated turbulent burning velocities were 4.6–6.5 times greater than the laminar burning velocities and about 13–20% lower than those obtained by flame chemiluminescence imaging.

I wonder if that was an engine built to run on ethanol? I know there is a ton of power to be made by running alky, but to take full advantage of it, you need to build the engine around the fuel. (sprint car guys as an example). There's a lot of advantages, like less temp, no pre ignition, and you can really put the boost (or static compression) to it. I'm just not sure that you can gain a lot by simply changing the tune.
I'm far from an expert, all the alky engines I've been around have been in sprint cars, so I don't have all the answers, but when I saw the flame front statement, I had to question it, as an example, if you dump a quart of gas and a quart of alky on the ground and light it, the gas will burn much faster, so it seems odd.

 

[Boone]

I agree that it is best to design an engine around the anticipated fuel. In my case, I have options. A test pull on a chassis dyno resulted in 519 whp with only 8 pounds of boost. This is a break in tune, and very conservative. After the final flex fuel tune, if I want to lock into the E85, I can change to a smaller pulley on the supercharger, and generate lots of boost to take advantage of the knock resistance of the E85. But that would yield more power than I want at this point in time.

A little more research on the flame speed question shows that ethanol flame fronts are indeed faster than gasoline (about 25% faster for E85). One paper I ran across showed the optimized timing for the ethanol fuel to be 5 degrees RETARDED from the optimal gasoline timing. It goes against what we thought we knew on making power with gasoline. Raise octane, and advance the timing. The flame speed difference throws the old manual out the door.

For me, this means that I'll optimize my timing for E85, keep boost levels low, and run gasoline only when I need to... but at least I will be able to run gasoline.

 

[Fabman]

IMO there's no need to even deal with E85, Sal runs that corrosive stuff in his supercharged car on track days to prevent the Intake Air from pulling timing (among other things) You will go through a ton of that stuff as well. You must realize that there are 2 ways to measure octane, the good way, is strictly by octane measurement, the 2nd IMO crappy way, is by the fuel's resistance to knock, so, E...whatever is clearly resistant to knock to it gets an (artificially) high octane rating, I would assume that water would get a even higher number. but you can't run your car on it. Another way to prevent knock is by water injection, but again, you have to balance that by increasing fuel, timing and compression. You live in NC, I don't think there are any emission tests there, just pull the cats, shut off the down stream O2 sensors and run race gas on track days. I think you'd be much farther ahead.

Water/Methanol Injection Systems at Summit Racing

Find water/methanol injection systems for gasoline and diesel applications at Summit Racing. We’ve got Snow Performance, AEM Electronics, and Banks methanol injection kits.<br />

www.summitracing.com

Boon has the whole top end of my Blown 3v stoker monster. Blower, heads, cams, ID1000 injectors, fuel rails etc.
e85 was worth 150 HP and 200 # torque on that motor. Blower motors love e85.

Now the N/A Coyote I replaced it with only made 12 more HP on e85. It doesn't have the compression or boost to take advantage of. However, I still choose to use it though because 1) its way cheaper than race gas and 2) it has a cooling effect on the motor. Both worth the price of admission IMHO. Yes, I use a little more fuel, but at 3 bucks a gallon I'm still saving a ton of money and I just have to carry a little bigger cell.
I'm currently burning 15 gallons in a 35 min race at Laguna and that includes a 30 min warm up. (got lots of oil to heat) The fuel isn't actually corrosive, it's the water that sometimes enters the fuel system (or storage containers) if not properly handled. I store my fuel in a sealed drum (not plastic fuel jugs unless transporting to the track). I don't leave the cap off my fuel cell and don't expose it to atmosphere unless actively refueling. I don't even know how many years I've been running it exclusively and I've never ever had a problem. In fact, the fuel I ran at Laguna this last weekend was pump e85 left over from march 2018 when I blew up that stroker motor at the first race of the season.
One tip I can give you Boon is to add a little top lube to the fuel. 5 ml/ 5 gallons for racing.
It lubricates and promotes ring seal. PM me for details.

 

[Stangra]

...add a little top lube to the fuel. 5 ml/ 5 gallons for racing.
It lubricates and promotes ring seal...

↑↑↑ This ! ↑↑↑

 

[Fabman]

Look at the various tunes here, starting with 91 octane and moving to 100 octane and finally e85.
Timing and boost was adjusted accordingly, which is the whole point of e85.

 

[blacksheep-1]

What do you guys use for "top lube" with the alky? the reason I ask is open kart racers have been running alky for decades and they run a 2 cycle mix type of oil. the reason I mention that, is that 2 cycle lube is designed to burn in the combustion chamber.
I put 2 cycle lube in every bit of fuel that comes on my property, the reason is, if I happen to be out of town or the wife needs to do some yard work, she can run that stuff in any engine, 2 or 4 cycle and it won't hurt a thing. I have an ancient 1974 Sears Craftsman yard tractor that I've run that stuff in and it is still alive.

https://klotzlube.com/

 

[Fabman]

What do you guys use for "top lube" with the alky? the reason I ask is open kart racers have been running alky for decades and they run a 2 cycle mix type of oil. the reason I mention that, is that 2 cycle lube is designed to burn in the combustion chamber.
I put 2 cycle lube in every bit of fuel that comes on my property, the reason is, if I happen to be out of town or the wife needs to do some yard work, she can run that stuff in any engine, 2 or 4 cycle and it won't hurt a thing. I have an ancient 1974 Sears Craftsman yard tractor that I've run that stuff in and it is still alive.

https://klotzlube.com/

I used to use klotz in the fuel of my rotary powered race cars back in the day, so using toplube in this car doesn’t seem so foreign to me. This is what shaun recommended.

 

[blacksheep-1]

I think Marvel was first designed, back in the day for a top engine lube, but they hit upon a combination that works so well, everybody uses it for virtually everything from top lube to air tools.
It's funny that back in the late 60s we were launching big block Chevys at over 10K and shifting them at 9500. People think this is something new. (doing in on a points triggered electronic ignition as well)

Here's Auto Meter's high zoot tach. I'm sure it's reasonably priced... lol

5

8199-05702 Gauge, Tach, 5

www.autometer.com

 

[Fabman]

I think Marvel was first designed, back in the day for a top engine lube, but they hit upon a combination that works so well, everybody uses it for virtually everything from top lube to air tools.
It's funny that back in the late 60s we were launching big block Chevys at over 10K and shifting them at 9500. People think this is something new. (doing in on a points triggered electronic ignition as well)

Here's Auto Meter's high zoot tach. I'm sure it's reasonably priced... lol

5

8199-05702 Gauge, Tach, 5

www.autometer.com

That’s what I said when he showed it to me: “air oil?”
I’m afraid to use this tach as it may cause re productive harm....
Just when you thought california couldn’t get any more rediculous.

 

[TMSBOSS]

I’m afraid to use this tach as it may cause re productive harm....
Just when you thought california couldn’t get any more rediculous.

You folks in CA must mount your tach differently than most folks.

 

[Fabman]

You folks in CA must mount your tach differently than most folks.

Not this guy....

 

[Boone]

Thanks for the tip. One of the reasons there is 15% gasoline in E85 is cylinder lubrication. I can see how a small amount of a dedicated lubricant can keep things a little happier. When I switch over to E85, I'll make sure to add a little Mystery Oil to the mix.