Started new E-85 topic from the "EFI for stock 440" thread.

https://board.moparts.org/ubbthreads/ubbt...440.html#UNREAD

Anyhow, Here is what I was thinking:
In theory, comparing 1000 cfm air flow (my carb size) on E-85 and Gasoline.
The data listed was just from a quick internet search, but this these are the values I found for the various conversions:
A pound of air is about 13.15 cubic/feet (normal temp/sea-level conditions?)
so 1000 cfm would be about 76.0456 pounds of air a minute?
I divided that by the air/fuel ratio to get pounds of fuel/minute using the 116090 for gas and 84250 for E-85?
This gave me 5.173 pounds of fuel/minute on gasoline, and 7.839 pounds on E-85.
Converting the pounds to gallons using 6.2 pounds/gallon gasoline and 6.59 for E-85 I get 0.834 gallon of gas and 1.189 gallons E-85?
I then multiplied the gallons of fuel by their BTU and got 96,863 BTU (per minute) on Gasoline, and 100,227 BTU on E-85?
So it looks like the E-85 has about 3.3% more BTU for an equal amount of airflow? This ignores the octane and cooling effects.

I have read that E-85 is supposed to be about 5% more power overall?

You're missing out on mechanical efficiencies. Compression and other engine bits that change to optimize for a specific fuel will alter the efficiency of the engine.


What got you so interested in air volume instead of fuel?



*edit* Forgot you were in CO. Density will throw a wrench in things too. Pumping losses, etc.

Engine power is limited by airflow not fuel flow.

Mainly interested because I just converted the Charger from Race gas to E-85 (12.4:1 compression.) Carb sizes were close to same flow rating, but not the same 1,000 cfm Holley HP on race gas to 1,050 QF E-85 carb. Both 4150 style carbs. Engine runs cooler on the E-85, but power seems down a bit, but I haven't tuned the E-85 carb and it is running rich.

If it stops snowing I hope to get the car out to the Lincoln Tech car show this weekend.

^^ have a A/F meter?

If you feel limited by a 1050 carb you must have a mighty impressive engine.

Guys are going plenty fast on less carb.

The altitude here is killing me...
It's the 499" stroked 400 with the Hughes CNC M/W heads, and 0.726" lift solid roller. I think either 272 or 274 @ 0.050" intake duration, a bit more on the exhaust. Been awhile since I looked at the spec card. No power adders, I'm sure nitrous or forced induction would help. Most of the non MOPARS I race are running some sort of power adder.

It's in the works...
Switching out the Edelbrock XT EFI computer on the Convertible with a FAST XFI 2.0 box, so I won't need the MTX Wideband O2 currently in the Coronet. It will be in the Charger later this year.

Tuning what you've got will likely make up the difference.
I imagine the 1050 will feed your engine just fine even with the density issue.

Just ran a 500" 440 on the dyno, similar cam, 915 heads. It made 650 up on e85 and 635 on race gas with 18 ft lb more tq. on e85.

I think the carb size is Ok also. Really at this point I'm already making more power than I can hook up with 27x 10.5 ET Radials and a near stock suspension on a 4,150# car.
I still need to put a roll bar in the car too, and maybe change out the 45-year old seat belts.

I didn't see where in your original calcs' you allowed for the air displaced by a greater amount of e85 needed, or did I miss that?

Using the BTU numbers to get pounds of fuel a minute? I think the math is off.

E85 has 2/3's the energy content of gasoline, so you'd need to burn more than your calc's should to equal the gasoline hp levels, all else being the same.

Tuning E85 for the strip is easy if you have an AFR gauge. Set your AFR gauge to read the lambda scale. Tune to read 15 to 20 rich or 80 to 85 lambda as you cross the strip. Mine is tuned at 83 lambda. The great thing about E85 is temp and humidity has little effect on your tune. I check mine every pass and it's always with in one or two numbers either side of 83. I haven't changed jets since the initial tune over six years go and the car always runs the number. I'm running a 496 stroker with a quick fuel 850 E85 carb. Jetting is 93 square. I shift at 5800 and cross the strip at 6000. The car runs consistant 6.5s in the 1/8th mile.

Wrong.

E85 SE (specific energy) is 9825 and E0 gasoline SE is 7891.

Don't know where you got your statement from, I'm thinking some orifice.

http://www.energyalmanac.ca.gov/transportation/gge.html

Heat (energy) value by the air/fuel ratio (Btu/lb ÷ A/F).
That ain't any ortifice talking, just mathematics and science.

I've dyno the same motor on both 110 octane race gas and local pump E85 that tested to be E90. That motor, after jetting for best power for both carbs. and fuel lost 12 HP(687 on gas to 675HP on E90) at 7000 RPM and gained 22 ft lbs of torque at the same peark torquue RPM) by switching to the E90 The E85 carb(Holley 1150 CFM Dominator converted by AJ Castelinin on here) needed leaning down 3 jets sizes to get best power as I was testing in Klamath Falls , OR at 4399 Ft in the spring, the Holley #9375 non HP 1050 CFM Dominator carb. didn't need jet changes, it like the stock jetting on that fuel that day with that weather BTW, my new car on E85 is way more consistent from morning to late afternoon now than the other race cars where on race or pump gas IHTHs

You can flow more E85 if you heat it as well. That is a trick if you believe the engine is lean and you can't move enough fuel. The heat changes the viscosity of the fuel and will it to flow quicker.