anybody here run alchol? besides a larger pump,and different carb what is needed?And what is different about the carbs.
I run alky. What do you want to know?
I've run carb before, home-brewed conversion, and done right. Ran it for a few years, was pretty consistent. Someone made me an offer on it and I could NOT resist, so I sold it, and used that plus about $150 for a Rupert carburetor. The Rupert was about .1 quicker and 2.5mph faster, in the 1/8 mile. This tells me that no matter how well you think you know how to convert a carb to alky, the guys who do it for a living know it better. The Rupert also never milked the oil, idled clean from cold engine to hot engine, was easy to build heat in the engine from first start of the day. Excellent carburetor for alky-if one wants a carb.
Keep in mind that a circle track carburetor is WAYYYY different than a gas carburetor. It might look the same externally but everything else is different inside. Will a cheap carb work? Yes. Will it work as good as a good one? Not a chance...
Now then......Few years later I was at a race and had an accelerator pump diaphragm start to leak in the semi-finals. 'Course that was the end of the day for me. Not going to risk burning up the race car over a $5.00 diaphragm, nobody had one either. Loaded up and went home. Yes I fixed it and ran the carb another year or so. Someone had mentioned that they had a used injection setup for cheap so I jumped on it, figure why not. I pickled the carb and set it on the shelf sealed up good-just in case I wanted to go back. It took me a grand total of 30 minutes to figure out how the injection system works, and 2 race meets to have it dialed in. Since then, it's never really been apart. Sent the pump back to Ron's and it checked out fine. Only reason I sent it in was because I had seen a tiny bit of alky under it while sitting in the trailer. Turned out to be a leaky hose. Easy fix. Injection is roughly a tenth faster than the Rupert carb was. So that's about a .3 improvement over a gas carb, and about 3 mph.
converting from a gas carb to methanol, you're going to want to do it right the first time. Alky is misleading. The fuel burns "cooler" so it's real easy to burn a gasket, torch a head or block or piston if the timing and or fuel isn't right. Too rich, and it's hard on rod bearings. The engine will tell you but it's nothing like a gas engine. A lean methanol engine will just run weak, without much miss or pop. Next thing you know, you're down on compression in one or more lungs.
You'll need a front mounted fuel cell. Rear mount just doesn't work that well. It can, but its cheaper to run a front mount from the get-go. To run a rear cell, you will have to install a surge tank out front, which is basically a fuel cell with a holley float bowl on it so that it won't over fill. To me, might as well just run the cell in front anyway if you have to put in a surge tank.
Pump-you'll need TWICE+ as much fuel volume capability. You'll use twice as much fuel. I use about 1 gallon per pass (around 700 hp small block N/A). Then of course all your lines will have to be bigger. Most guys including myself who have converted from gas to methanol have used electric pumps and they work in real low power situations (like under 400 hp) but it is MUCH easier to run a belt or cam driven mechanical fuel pump. Most of us who have converted have eventually gone to the mechanical pump. Changing everything over from the get-go is cheaper if you do it right, which is why I suggest calling George Rupert if you're set on a carburetor. His stuff ain't cheap. But neither is doing it twice + fixing a few engines.
Injection on the other hand is so simple, it's crazy. I run a flying toilet. I have also run a terminator. Both work on the exact same principle but the terminator is a 4 hole throttle body and the toilet is a big single blade. The terminator gives you better idling characteristics in the pit area, easier to drive around, and the toilet is a little more responsive out on the race track-which is important to me since I'm foot-braking. The instant you touch the throttle, you're hauling booty. And it is instant. Yes you can drive in the pits with it, and pretty easily. At least I can. There are no accel pumps to leak. No power valves to die. No gaskets. Only a pump, valve/block, and a throttle body, then 8 injector nozzles....and that is all there is to it. Simple. I put mine on in 2008 and I still have the exact same nozzles and everything. I change the pill once a season to lean it out for summer time, since we'll start the season racing in the 50's and in the summer it'll be in the 110 area sometimes with humidity to boot. So I'll put a bigger pill in to lean it out (yes backwards of a carburetor, bigger pill=leaner, small pill=richer). Same principle as an 8 stack on a sprint car or a top fuel car for that matter, mechanical injection is all the same for the most part.
Also, with mechanical injection you can mix in a little nitromethane if you want, but you have to be really thorough and really careful with the stuff. It's like a turbocharger. You can mix it at 5% and be .2 quicker. That feels really good, so you want a little more after while. Then you're at 20% and a half second quicker. But the thing is, stuff is real hard on engines. Blocks and crankshafts, bearings, and head bolts especially. I suggest staying away from it. VP makes some fuel called M5 Methanol which is something like 5% nitropropane mixed in with methanol. It's worth about a tenth over regular methanol but you better have good eye and nose protection because the fumes are nasty. But it's really consistent. I have about 10 gal left over and need to use it up. I just hate the fumes.