Alcohol and SBM.
- Thread starter tvt59
- Start date
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Rat Bastid
Dunamis Metron
IMO, you can (and should) make the same power on gasoline as you do alcohol IF your cooling system is capable of keeping the engine cool enough for gasoline.
Most guys think 180 degrees at the start of a run is good for gasoline. A gasoline burning engine shouldn’t see the high side of 170 at the end of a run.
Gasoline hates heat.
Alcohol on the other hand loves it. That’s partly because you are stuffing 2.2-2.5 times as much alcohol through the engine as you do gasoline. You have to atomize, then vaporize ALL that fuel to get it to burn.
I‘d have no issues leaving the line at 190-195 and hitting 220ish through the lights IF your cooling system (with the help of the alcohol) can get the temp back down to 180 or so on the return road.
Alcohol requires different cam timing than gasoline does. The intake charge is wetter and therefore heavier than the same charge (meaning the same charge to make the same horsepower) for gasoline. The mass of air/fuel is harder to get moving and harder to stop. And harder to turn a corner or change directions. You should consider that when porting for alcohol verses gasoline.
As far as lean out valves and stuff like that…IMO you need to dial in your tune up, get your engine temperature up and clean it up that way. They don’t need to be drooling, sloppy rich to make the best power. They can be, but don’t NEED to be.
If I’m driving the car to the staging lanes and back to the pits I’m running a power valve on the primary side. If you don’t, it will be super pig fat rich and miserable to drive and it will stink far more than it should.
Learn to read your plugs and trust that.
If you are milking the oil, that’s a tuning/temperature issue. Get that squared away and you should have relatively clean oil. And the extra coolant temp will vaporize more of the fuel, which reduces crankcase fuel dilution.
Also, never ever run Group IV or V synthetic base oil engine oils on alcohol. The two (alcohol and Group IV and V base oils) are wholly incompatible with each other.
If you do try it, you will notice any alcohol that gets past the rings will act as a solvent to the oil and cause the additive package (apart of it anyway) to separate from the base oil. That’s not good and I’ve seen it first hand many, many times. There are a couple of companies out there still claiming you can do the IV and V base oils with alcohol but they are fibbing at best.
You can use a Group III “synthetic” because it’s really a highly Re-refined mineral oil. It only gets labeled as synthetic because the courts made a mistake.
Most guys think 180 degrees at the start of a run is good for gasoline. A gasoline burning engine shouldn’t see the high side of 170 at the end of a run.
Gasoline hates heat.
Alcohol on the other hand loves it. That’s partly because you are stuffing 2.2-2.5 times as much alcohol through the engine as you do gasoline. You have to atomize, then vaporize ALL that fuel to get it to burn.
I‘d have no issues leaving the line at 190-195 and hitting 220ish through the lights IF your cooling system (with the help of the alcohol) can get the temp back down to 180 or so on the return road.
Alcohol requires different cam timing than gasoline does. The intake charge is wetter and therefore heavier than the same charge (meaning the same charge to make the same horsepower) for gasoline. The mass of air/fuel is harder to get moving and harder to stop. And harder to turn a corner or change directions. You should consider that when porting for alcohol verses gasoline.
As far as lean out valves and stuff like that…IMO you need to dial in your tune up, get your engine temperature up and clean it up that way. They don’t need to be drooling, sloppy rich to make the best power. They can be, but don’t NEED to be.
If I’m driving the car to the staging lanes and back to the pits I’m running a power valve on the primary side. If you don’t, it will be super pig fat rich and miserable to drive and it will stink far more than it should.
Learn to read your plugs and trust that.
If you are milking the oil, that’s a tuning/temperature issue. Get that squared away and you should have relatively clean oil. And the extra coolant temp will vaporize more of the fuel, which reduces crankcase fuel dilution.
Also, never ever run Group IV or V synthetic base oil engine oils on alcohol. The two (alcohol and Group IV and V base oils) are wholly incompatible with each other.
If you do try it, you will notice any alcohol that gets past the rings will act as a solvent to the oil and cause the additive package (apart of it anyway) to separate from the base oil. That’s not good and I’ve seen it first hand many, many times. There are a couple of companies out there still claiming you can do the IV and V base oils with alcohol but they are fibbing at best.
You can use a Group III “synthetic” because it’s really a highly Re-refined mineral oil. It only gets labeled as synthetic because the courts made a mistake.
I just installed the Pro Systems alcohol fuel system and carb. I've not made any passes yet. It doesn't appear to be super rich. I've idled it in the shop for several minutes and it didn't run me out. My carb didn't come with power valves but I've always used them in everything I've ever had. I like for it to be clean on the return road and in the pits. It sounds pretty snappy and I've always ran my stuff with smaller jets than most other people. I think I'm going to go ahead and put a lean out on it just incase. The oil I currently use is Lucas Synthetic Racing oil. Would you think that is compatible?
Rat Bastid
Dunamis Metron
Not sure on what base oils Lucas uses. I’d call them and ask.
According to their website it's a blend of group III and group IV oils
Rat Bastid
Dunamis Metron
I’ve never seen that so I’m not sure. Chances are it will work because is suspect it has more Group III oil than IV. I wouldn’t be afraid to try it. You’ll know pretty quick if it’s not working because when you drain the oil out you’ll see long, stringy plastic coming out. That’s part of the additive package.
Then there's the neglect. These "pros" would load the cars after race night, never check on the fact that their carbs were pissing out. They even bent a rod because of it (hydra lock), TWICE. High tide mark visible on the one.
I'm not sure what my end on the night routine will be. But I'm thinking of running all of the alcohol out of the carb. Then putting gasoline in the front bowl run that out Then put gasoline in the rear bowl run that out and load it up.
Lol your avatar
@Oldmanmopar knows about that stuff. I think he's done methanol racin before. Maybe he'll chime in.
@pittsburghracer runs alcohol in his SB, maybe he can chime in.
He wants to run power valves so I can’t help him. I haven’t ran a power valve in 47 years.
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