Alchohol Conversion???

[Corzette]

Can anyone tell me what is needed to run alchohol on the 350? Do I need to just buy an Alchohol carb and go or???? How much HP gain should there be between the two. Im at 400 now.

 

Terry

[dr_hunt]

First of all let me say that if your fuel system is alcohol compatible you can always run gas, just by changing carbs. That being said the following is true to the best of my experience. BSFC for alcohol is 1, which is twice that of gas so you need bigger fuel lines than you do for gas. A -8 or -10 is pleanty. If you have a fuel cell already, take the foam out, alcohol eats the foam. Alcohol runs $110/55 gallon barrel. Race gas here now is $325/55 gallon barrel and I've been told is going up. You use twice as much but if you do the math, it's still cheaper than gas and you get the big gains. If you had a heating problem, alcohol will solve that in an instant, even without a thermostat, expect engine temps to hover around 150 depending on jetting and size of rad. If you richen up the mixture engine temp will lower, opposite for leaning it out. Expect ice cold intake manifold temps and after a run on a humid day, don't be suprised to see ice on the outside of the intake manifold. Rich and Lean sound the same as Rich does when running gas, so read the plugs or start rich and lean out until you don't see any more drop in quarter mile times. Alcohol jets jump a size, ie. 146, 148, 150, etc. which is a normal gas jet size times 2, so a starting point is 2 times whatever jet size you ran on gas, maybe one or two more sizes up to start. Lean is mean, but melts pistons, so be carefull or it'll melt a dime size hole in a piston real quick.

 

If anybody needs fuel cell foam, I have foam from two 12 gallon cells.

 

Alcohol compatible fuel pump is required, alcohol compatible fuel filter which is just brass screen type. Alcohol fuel pressure regulator, which is some of the more high end regulators, they have teflon seats and seals. Alcohol carb, Holley, DaVinci, BoLaws, BG, C&S, etc. all make fine carbs. If you have all that and save your gas carb, you can always change to gas by just switching carbs and adding gas.

 

HP gain, depends on the carb. You'll pick up a half second in the quarter as a general rule. I picked up 8mph on the top end. Mainly it picks up Torque throughout the whole rpm range but especially in the midrange. My 60' times dropped 2 tenths and I picked up 7 tenths in the quarter mile on a compression motor and 9 tenths on a 9:1 motor, but the carb size wasn't the same so that probably accounts for the larger gains. I went from a box stock 750DP to a C&S Aerosol Billet 900cfm cause they come with a 30 day money back guarantee, no questions asked.

 

Alcohol is hydroponic, which means it attracts moisture from the air. Maintenance is an issue if the car is going to sit for awhile. Alcohol also eats natural rubber. Drain the lines, tank and carb, spray penetrating oil in the carb and pump or do like I do, change to gas carb, clean alcohol carb, pump out the alcohol back into my drum, add gas and run till it clears up, good to go. Takes me 20 minutes to do all of that at the end of the day. I've left alcohol in the system for a week or two, but this is the dry southwest. Changing to alcohol is like adding a 50-75 shot of NOS IMHO.

[Corzette]

Thanks Doc. Well so far I have the Aeromotive regulator which is alcohol ready. My fuel pump in the Holley Black so that is also compatible. I have an aluminum fuel cell so I will need the additive for that right? My fuel lines are braided steel rubber lines that everyone has. Do I need to change those? My fuel filter is a PAXTON. I think it is alcohol compatible too. Its the BIG BLUE one with O-ring seals and -10 inlet and outlet as seen here at the top http://www.tweakit.net/shop/product_info.php?cPath=&products_id=358 Anything else to ponder? Jets are usually twice the size of gas right. Im thinking of an 850 carb for the alky.

 

Terry

[dr_hunt]

As far as the hoses go they are fine, I've been running alky for 3 years and not a sign of a problem. The additive I use is an upper cylinder lubricant from Red Line which is avail on ebay for 5 or 7 bucks, one bottle does a whole drum. The fragrance also works well so that the fumes don't sting the eyes. I don't run a fuel filter yet. The Aeromotive pump has a screen on the inlet side.

 

When the engine is cold, they are hard to start on alky, alky doesn't flood the engine like gas does. I squirt some gas in the carb when cold for the first start. Low compression engines are harder to start than high compression. And by cold I mean like 60 degrees, colder than that and even the high compression motors are hard to start. Alcohol usually requires a different plug, a little colder works for me. I'm running an Autolite AR3932 gapped at .025 for the AFR heads.

 

Alky engines are clean, in the combustion area, but the byproduct of the combustion is H2O, so what you'll see is a milky color to the oil after awhile. You have to change oil alot more often and don't be suprised if you pull the valve cover and find water beads everywhere. A vacuum system eliminates alot of that but I've never had any detrimental problems. Use a synthetic oil like Mobil1. I race with a 5W-30 as it's easier on the distributor gear IMHO.