Alcohol properties

Turbo__Tim

One heck of a Tim!
Here is a post contributed by Steve Wood and contains materials from several sources. Great for anyone that is looking for some sound theory, and a peek at what Steve Yaklis is doing with alchy. It is interesting as to how much alchy he sprays (18 percent of the final mix) and the way he drops fuel pressure to allow for more alchy. Anyway, here it is...

This is a bit long but as Steve H and Denis K have pushed the boost and timing way past most of us, I think it is worth thinking about. Note how much they are injecting. They are using a lot of pressure and fogger nozzles...(technical term for Aquamist

Steve Y thinks they get away with 28-29# of boost and considerable timing because they use relatively small turbos. He has noted that larger turbos are more sensitive to timing. I don't know. He has sprayed more methanol than most of us will ever consider so he does have some experience:


From Steve H's Word doc.


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Methodologies
Water injection, or water/alcohol injection, acts as a highly effective gaseous intercooler. The only reason for an intercooler is to cool down the hot, compressed air from the turbo. Water can do this job far better because it has a very high property of Latent Heat of Evaporation, 500+ BTU’s compared to gasoline’s 135 BTU’s. and alcohol’s 470.

If you need a bit of extra fuel, a 50-50 ratio of alcohol to water strikes a good balance between the maximum anti-knock capability of water and maximum supplemental fuel.
For example, I use the alcohol as a supplemental fuel source, which allows me to relax my fuel pressure and continue using injectors which are currently max-ed out.

It’s interesting to note that at the relatively high flow rate we use in our system this extra fuel source accounts for approximately 18% of my total WOT fuel requirement.


Alcohols
There are different forms of alcohol which range in BTU’s from approx. 8100 to 9700:
Isopropyl - common rubbing alcohol.
Ethyl alcohol - the type used for consumption.
Methanol - highly corrosive, difficult to find, has the highest oxygen content, highly toxic.
Denatured alcohol - Ethyl alcohol to which a small percentage of Methanol and other chemicals have been added to make it poisonous. It has a high BTU value, is widely available at most hardware stores and is relatively safe to handle.
For these reasons Denatured alcohol is the preferred type of alcohol to use.


Pumps
To satisfy the requirements demanded by the turbo Buick we need a high flow, high-pressure pump, such as the ShurFlo 8000 or the FlowJet 2130 series. These pumps will tolerate alcohol and flow about 2 gpm at 90 to 100 psi. If using the ShurFlo be sure to order the optional Pump Bypass.
This will insure 90+ psi pressure.


Nozzle Types
There are a number of suitable nozzles such as the NOS-type, oil burner type, irrigation type, etc. You may pick your nozzle type based on price, size, ease of installation, or whatever suits you.
Although nozzle type is not critical, per se, the better atomization the nozzle achieves the better the ultimate performance. In any case, multiple nozzles are indicated when flow rates exceed a certain level.

I have hands-on experience with only two types, which I’ll discuss:

Oil Burner Type
A single, “oil burner”-type nozzle will work well, especially on stock engines running boost up to 16-18 pounds. These nozzles are large which means you’ll need the large ‘weld-o-let’ bungs available from Carrolls Supercharging to mount the nozzle to your up-pipe. A system with a single nozzle is simple and inexpensive. For higher flow dual oil burner-type nozzles will yield better control and the necessary spray volume without drowning the engine. A system fabricated around these nozzles can be done relatively cheaply.

Aquamist Type
Aquamist nozzles work exceptionally well. They require specific tubing, connectors and adapters, but I believe these nozzles are superior and well worth the additional expense.


Fluid Volume
Depending upon turbo size, intercooler efficiency, boost pressure and spark timing, the water or water/alcohol spray volume for all nozzle types will likely be between 15 and 30 gallons per hour.


Pump Control
The usual method of controlling the pump is through the use of adjustable Hobbs switch(s). These can be purchase with high current rated contacts which allow direct pump operation w/o the need of a high current slave relay.
Both low and high current rated Hobbs are available from a variety of sources, including Carrolls Supercharging and ShurFlo and many GN parts vendors.


Plumbing
This is an area where you are free to use your own imagination for location. Just remember, your system will use a generous amount of fluid and a two quart reservoir will be sucked low in about 4 full quarter mile runs.
Therefore, depending upon personal driving style, you should plan your tank capacity accordingly.

Examples:
Steve Hill locates a 2.5 gallon tank in the trunk. Fluid is transferred to the smaller windshield washer reservoir via a generic windshield washer pump. A Carrolls (modified Flojet 2130-xx) high-pressure pump, mounted in the engine compartment, sucks from this supply.

This design is somewhat complicated because of the extra systems and plumbing needed to supply the windshield washer reservoir and keep it full.

Denis Kefallinos mounts a 2.5 gallon tank in the trunk. He also locates his high pressure ShurFlo pump in the trunk. In this design he pushes the fluid forward to fill a much smaller, 2 qt pressurized accumulator, which can then be released under full pressure to the nozzles via a Hobbs-activated solenoid valve.

This is a less complicated and much cleaner looking system than mine.

Bob Avellar has his front mounted high-pressure ShurFlo pump suck directly from the windshield washer reservoir.

This is a nicely compact design which may require more frequent refills due to the relatively small washer tank capacity.





Tips

Before installing a water/alcohol system, record your engine parameters wot
Keep the pump and tank lower than the nozzles to help limit siphoning
Always use an in-line filter on the outlet side of the pump
Avoid line restrictions such as a check valve.
Use the black fuel pump test connector as a source of switched power for the pump relay
Try to keep DeltaP ( pump pressure minus boost ) at 60 lbs psi or better.
Use EGT and knock counts for precise tuning.
Use a cold spark plug


FYI Facts

Energy Content Heat of Vaporisation Oxygen Content
Nett MJ/kg MJ/kg wt%
Methanol 19.95 1.154 49.9
Ethanol 26.68 0.913 34.7
MTBE 35.18 0.322 18.2
ETBE 36.29 0.310 15.7
Gasoline 42-44 0.297 0.0

Methanol Ethanol Gasoline

RON 106 107 92 - 98
MON 92 89 80 - 90
Heat of Vaporisation (MJ/kg) 1.154 0.913 0.3044
Nett Heating Value (MJ/kg) 19.95 26.68 42 - 44
Vapour Pressure @ 38C (kPa) 31.9 16.0 48 - 108
Flame Temperature ( C ) 1870 1920 2030
Stoich. Flame Speed. ( m/s ) 0.43 - 0.34
Minimum Ignition Energy ( mJ ) 0.14 - 0.29
Lower Flammable Limit ( vol% ) 6.7 3.3 1.3
Upper Flammable Limit ( vol% ) 36.0 19.0 7.1
Autoignition Temperature ( C ) 460 360 260 - 460
Flash Point ( C ) 11 13 -43 - -39


Vendors and Informational Web Sites

Jay Carter Kits, sold through OGS, http://www.webdynamics-nj.com/OnlyGoodStuff/
Steve Chluspa, SMC Enterprises http://www.geocities.com/rad87gn/tech/SteveCkit.html
Steve Monroe’s web site, http://home.att.net/~stevemon/AlcoholInjMod.html
Carrolls Supercharging, www.carrollsupercharging.com
Chad Schwartz web page, http://www.geocities.com/rad87gn/tech/alcohol.html
Joe Tripodi, http://www.servtech.com/~racerx






A review of important points
Just realize that the higher boost and/or the smaller the turbo, the greater the heat that must be removed.

A mix of denatured alcohol will provide extra fuel (going towards rich) which must be adjusted for.

With the systems described in this primer, you'll need to spray a large quantity of fluid. Use nozzles rated (usually) somewhere between 12-23 gph.

Pump pressure should be 60 lbs Delta or better.

Multiple nozzles allow better atomization characteristics.

Get your car running properly on pump gas *first. Record egt, knock and fuel pressure. You’ll use this data as reference when on water/alcohol.

When you start to mix in alcohol your O2’s will tend to rise slightly on the rich side.
Adjust fuel pressure and boost accordingly.

Monitor knock and adjust boost until egt’s come back into the range you want, or until boost is where you want. You can remove fuel pressure one pound at a time to get higher (leaner) egt’s, and/or adjust alcohol. Monitor knock carefully (see below “words about knock”).

Knock will become your most reliable tool for gauging performance.

Direct Scan is highly recommended for your scanner requirements.


A few words about knock
SUSTAINED knocking is most harmful, especially when the knock starts to spike higher and higher in a saw tooth-like pattern. This is runaway detonation, in one or more cylinders, and is highly damaging to engine components. This type of uncontrolled knocking is what you would get when running insufficient octane and/or air fuel ratio for the boost and timing.

Knock SPIKES may be traced to distribution problems, where one cylinder may temporarily go lean, or to fuel/air flow instabilities at transient throttle. This is different from runaway-type knock.

At high boost/high timing you may see some intermittent spikes but these should be low intensity and decay quickly.
This initial “transient burst” knock phenomenon during the unstable region of wot is surprisingly common among modified turbo Buicks, and is not unique to water/alcohol systems.
About 1 second after going wot, engine fueling and airflow enter a more stabilized region of operation. At this point little or no further knock is expected. However, one or two degrees of millisecond-level knock spike no big deal *as long as knock decays quickly and stops*.
Again, this is not to be confused with sustained knock.

The water or water/alcohol should control most of this. You may have to live with some amount of knock spiking when engine parameters are in a state of flux, such as initial wot.

Parts Listing Courtesy Bob Avellar

SHURflo pump Model 8000
Northern Tool and Eqipment Co. Part# 2687-8216, List $100.95, discount price $69.99 (60psi @ 1.4gpm)
80-100 psi replacement pressure switch – optional
approx... $20. (raises pump pressure and is optional) Contact SHURflo for a distributor near you or Shuster Corp. 4 Wright St. New Bedford, Ma. 02741-3086 (508) 999-3261 part # 94-375-15 $19.30 + $4.80 C.O. D.
Water filter
$3.95 part# 81-0240 Carroll Supercharging Co. Inc. tel. 973/835-1705
3/8" barbed check valve
$3.50, part# 2431 Carroll Supercharging
12v Solenoid valve
$65.00, part# 359115 Carroll Supercharging
(2) Stainless Steel Nozzles
$5.95, Part # 1075 Carroll Supercharging or local plumbing supply $ 3.03 ea.
Oil burner nozzles rated in GPH and either 45 degree or 30 degree spray pattern.
Tank
$5.00, Salvage yard. I used one from a VW that is sturdy, has outlet at bottom and return at top.
windshield washer or coolant overflow tank will do
(4) 1/4" NPT x 3/8" Barbed elbows
$.50 ea. Part # L4-6BN Carroll Supercharging
3/8" Ball valve
$5.00, Home Depot
Fuel injection hoses 3/8" and 1/4"
approx. $10.00 ( lengths vary according to your arrangement of pump and tank) Approx... 8 ft. of 3/8" and 3 ft. of 1/4".
(15) (approx..) Hose clamps and assorted tees and fittings
approx.. $10.00
Hobbs pressure switches
$15.00 ea., Steve Chlupsa (adjustable 4-20psi)
(2) Relays, (30 amp)
$6.00 ea,. Radio Shack
Fuse holders, Assorted wiring
Radio Shack, lighted switch, a green and blue bulb, and connectors for attaching to relays, and switches (also need 1-3amp fuse and 2-10amp fuses) About $20.00
Outside Nozzle holders
Carroll Supercharging $10.00ea. part# 1582 (must be welded to uppipe) I had my own made from steel and TIG welded to pipe
Brass nozzle adapter
$5.20 ea. from local plumbing supply (brass- they came in 2 lengths but I think I used the short ones). Made for holding nozzles in oil burner.
3/8" X 1/4" brass bushings
$3.03 ea. From local plumbing supply. Might be to step down from 3/8" to 1/4" hose.
(2) 1/4" hose barb X M adapter
$.72 ea., local plumbing supply. ( screws into back of nozzle adapter and inside of the following adapter)
(2) 7/8". ODCOMP X 3/4M Adapter
$5.20 ea. From local plumbing supply. (These hold the brass nozzle adapters inside and the whole assembly screws into the outside nozzle holders.
 
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