390 CFM Holley alcohol carb?
#1
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Join Date: Jan 2004
Location: central Illinois
Posts: 459
390 CFM Holley alcohol carb?
A stock car guy brought me a Holley 4150 double pumper to rebuild. Said it ran great down the straightaway but blubbered bad in the turns. He is running Torco gasoline, he says. He thinks it is a 750 CFM carb. The choke horn has been removed , so no Holley number on it.
I noticed it looked a little strange when he left it off. It is. It is 1 1/8" venturis and 1 7/16" throttle bore. That makes it a 390 CFM I think. But when I took it apart it has stainless needle and seats, 90 jet size, .059" squirters and 35 power valves front and back. (It also had the back float shut completely off with the needle and seat run all the way down.) I think this has to be an alcohol carb.
Anyone have any input on this?
Someone went to a little trouble to make a small alcohol carb? Why?
I thought 309 carbs were pretty rare anyway?
I noticed it looked a little strange when he left it off. It is. It is 1 1/8" venturis and 1 7/16" throttle bore. That makes it a 390 CFM I think. But when I took it apart it has stainless needle and seats, 90 jet size, .059" squirters and 35 power valves front and back. (It also had the back float shut completely off with the needle and seat run all the way down.) I think this has to be an alcohol carb.
Anyone have any input on this?
Someone went to a little trouble to make a small alcohol carb? Why?
I thought 309 carbs were pretty rare anyway?
#2
No wonder it ran bad on gas.... :shock: Sounds like time for a new carb for him. Not sure who would run a 390 alky carb off hand. He probably had to close the back N&S to make the fuel close on gas for WOT, but would still be rich on part throttle. He will be MUCH happier when he gets a gas carb on it.