alcohol carb??

Reply Subscribe

Thread Tools

Search this Thread

Mar 14, 2007 | 11:48 AM

#16

dinosaurfan

Cargo Master

Joined: Aug 2000

Posts: 2,931

Likes: 12

From: SW Michigan

alcohol burning

Bear, just beacause we CAN run 50 or 60* of lead doesn't mean we should. I have to wonder if the guys running that much advance keep getting faster as they advance the timing, usually there comes a point of diminishing returns. If you keep advancing, the fuel burns too soon, and the piston actually has to compress the already burning mixture. But the alcohols have so much detonation resistance that you can get away with quite abit. I would suspect that the guys who run 50 or 60* of lead are suffering from ignition lag. By which I mean that there is longer period of time from when the spark arrives to when the fuel actually starts to burn. The alchohols both have a wider flammability spread and faster flame speed than gasoline, but they seem to need greater amperage at the plugs to get the fire lit. What type of ignitions are these guys running ? My guess would be that if they switched to an 8 amp system with copper wires and tried about .080 plug gaps, they wouldn't need so much lead. Duraspark, HEI and Chrysler's breakerless all put out about 4 amps, points run about 2.5. DinosaurFan, at work but on lunch

Mar 14, 2007 | 11:58 AM

#17

hoxiii

Postmaster

Joined: Jul 2003

Posts: 2,711

Likes: 2

From: Pittsburgh

Alcohol needs more juice to fire and bigger gaps becuase it runs at a much richer mix than gas and is more difficult to vaporize, so there are more and larger fuel particles to ignite.

And you definitley can start to lose power from over advanced ignition before you start to knock, so I too wonder if they run that much becasue they can or becasue they should,

Justin