Alcohol vs. Gasoline

[Guest]

I'm wondering if anyone has any experience with the power differences between alcohol and gasoline in a serious naturally aspirated racing engine. For example, what do you think would happen if a guy like Dean Carter with his injected alcohol smallblock were to switch to a good sheet metal intake with two carbs and gasoline? Or how about a strong PST 358 running on alcohol instead of gasoline? How does the fuel affect horsepower and torque?

[maxracesoftware]

Switching over to Methanol from Race Gas=>

1- Approx 8 to 10 % PerCent increase in Torque/HorsePower potential

.....most times, a simple switch over shows instant Low-end to Mid-range Torque and HP gains , but no real Hi RPM gains because Methanol reduces VE %, and Ports need increased cross-sect area, and Carb CFM has to be 200+ CFM larger to account for more wet flow loss -vs- Gasoline

2- Approx 10 % PerCent "LOSS" in Volumetric Efficiency with no other changes except Fuel switching

3- Approximately double CFM in Blowby readings
example=> 4 CFM on Gas = about 8 CFM with Methanol
using Methanol increases Blowby, Ring and Valve Seat wear
Increased water in oil.

4- Could run 16:1 CR + because Methanol in comparison to best Race Gas has higher effective resistance to detonation, and the other reason to run higher CR is because of the previously mentioned LOSS of Ve %.

if the Ve % Loss is corrected, Comp Ratio might have to go lower ?

5- to build a Methanol specific engine, then Intake port cross-sectional areas would have to be larger, Cam Lobe/Lift increased.
The Canted-Valve Chevy Head or similiar Head would allow more cross-sectional area / Flow / Valve Size


Header with Collectors could be used instead of "Zoomies"

[Swede Racer]

Hope you don't mind if I hijack this thread with a qouple of q:s

I've been thinking of using E85 for my race/street car. The Turboguys over here are using it with really good results, even in street duty.
E85 is the environmental friendly (supposedly) fuel consisting of 86% ethanol, 11.6% regular gas, 2% MTBE and 0.4% Isobutanol.

Racegas over here costs about $20/gallon and E85 costs about $4.30/gallon, soo, my reasoning was to build the engine too accept alcohol instead of racefuel.

Any insight on this? Good/bad idea?

What static comp should I aim for? What else is included in a conversion like this except upping the comp, alcohol carb and overkill on the fuelsystem?

All newbie questions....thankful for any input!

/Mike

[Grocerius Maximus]

One thing that was hinted at but not mentioned specifically- alcohol is an oxygenated fuel. It carries its own air so to speak. Off the top of my head meth is 10% oxygen by weight, eth is 7-8%. Alcohol also has a much higher capacity for heat than gasoline. It will absorb more heat from the inlet air and the surfaces it comes in contact with, a LOT more than gasoline.

It is also pretty darned cheap in volume. Not uncommon to be able to buy the good clean virgin (not recovered) meth for $90.00/55 gal barrel here in TX.

The biggest con is you must design the fuel system from the ground up to use methanol. Methanol attacks rubber pretty hard, and is corrosive to many metals. It also takes over twice the volume of gasoline to get the job done, so your lines, pumps, regulators etc. must be up to the task.

[Darin Morgan]

Switching over to Methanol from Race Gas=>

1- Approx 8 to 10 % PerCent increase in Torque/HorsePower potential

.....most times, a simple switch over shows instant Low-end to Mid-range Torque and HP gains , but no real Hi RPM gains because Methanol reduces VE %, and Ports need increased cross-sect area, and Carb CFM has to be 200+ CFM larger to account for more wet flow loss -vs- Gasoline

2- Approx 10 % PerCent "LOSS" in Volumetric Efficiency with no other changes except Fuel switching

3- Approximately double CFM in Blowby readings
example=> 4 CFM on Gas = about 8 CFM with Methanol
using Methanol increases Blowby, Ring and Valve Seat wear
Increased water in oil.

4- Could run 16:1 CR + because Methanol in comparison to best Race Gas has higher effective resistance to detonation, and the other reason to run higher CR is because of the previously mentioned LOSS of Ve %.

if the Ve % Loss is corrected, Comp Ratio might have to go lower ?

5- to build a Methanol specific engine, then Intake port cross-sectional areas would have to be larger, Cam Lobe/Lift increased.
The Canted-Valve Chevy Head or similiar Head would allow more cross-sectional area / Flow / Valve Size


Header with Collectors could be used instead of "Zoomies"

As far as my take on it, read what maxracesoftware wrote above one more time.
I personaly hate the stuff.

[kid vishus]

Here's been my experiance with it; the more efficeint the engine, the less gain, if any, it will see from alcohol. I know a couple of guys that have large inch motors with good gas carbs, that actually slowed down when they tried to run alcohol. Since all I have run is sbf cleveland stuff, I normally see a 4 tenths improvement when switching from gas to alcohol. I really think the overly large 4v cleveland intake ports are perfect for a NA alcohol. One motor that was 10.5-1 with open chambers picked up just over 4 tenths, while another motor that was 14-1 with closed chambers barely gained 3 tenths.
The water in the oil is something that is 'improve-able'. The water temp needs to be kept much higher than guys normally like to keep a dragrace motor. I try and keep mine over 180 after a pass, and after the last pass of the day, I get the temp over 200* before shutting it off. I then pull the breathers, and prop the carb open and leave it. It sesms to work as I don't get near as much water in the oil now as I did when I first started running it. Also, I have found in my case that running a good top lube will make the valve seats wear no worse than on gas.

[cleverlever]

This web site should be of interest to persons interested in alcohol fuels Page 10 http://www.creedproject.org/stream_v7n2.pdf note 20% increase in power when tested on E85. Mileage went down. Think of a stock Prius converted to Bi Fuel operation. Leave the stock system for the cruise mode and retrofit a single throttle body fuel injector in the plenum connected to a seperate tank with e85 that turned on only in the accelerate mode.

The basic idea is similiar to Nitrous except its GREEN and probably a lot cheaper

Another neat ideal for a bi fuel atkinson would be to add the VVTL-i feature to the Prius VVT-I to further increase low speed torque