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I'm confused

31 bucket

New Member
I have been reading through everybody's post and advise. The knowledge is awesome here. But I am running a supercharged 350 with dual 650 edelbrock vacuum secondary carbs. Plus a mag distributor. Haven't had this bucket that long. Noticed that jet screws are way different between left side and right side. My first blower engine. Almost sounds like over carbed and the mag isn't good for cruising. I'm trying to build it right and run great. I was always taught. Old school. Fuel. Air and strong spark. And obviously tuned correct
 
Is there a question in there somewhere ?
 
I believe those carbs have to be 1405's, not 1406 if that is what you have. There are also some parts that should possibly be changed to run a blower. I have a parts list that is a STARTING point if you need it.
 
I would very much appreciate your advice

Since it sounds like you have a carburetion issue, tell us how does it perform on the road? Does it bog off the line? Hesitate when your give it gas at cruise speed? Or sputter at part throttle? How does it idle?
 
Idle is great. I haven't accelerated past half throttle. It leaves the line fast. My mistake I did punch it at cruising speed. It popped once and died off so I haven't did it since. Fuel pressure is erratic. Idling is 6 pounds.
 
Jeez, for the price of two blower carbs you could have EFI and it will tune itself. Best thing I ever did. Once you've gone EFI you'll never go back...
If you want to stick with carbs it would be nice to get those built for blower, where the power valve is referenced to the MAP. If you use the plain old carbs the motor can go lean when you stomp on it (sounds like this is what happened to you). Many folks just richen the carbs to compensate, but the spark plugs will need more frequent cleaning.
I'm guessing you have a mechanical fuel pump. An electric pump will give you steady pressure.
 
In ‘72 when I built my blown motor I had chrome pipes and knew a lean mixture would blue them so I drilled all the jets in my new 500 cfm AFB carbs with an 1/8” drill bit and never had an issue! Being young and dumb I guess I was protected by a higher power!
 
Update: I researched my carbs and the 6:71 blower. I was given a baseline setup for my carbs. I'll have to look at the way it is now. As I said before. I haven't had the bucket very long. So it is all new to me. Was also told that blower engines need 12 to 20 degrees inital timing. Total at 30 to 32 degrees. I have a mag distributor and no vacuum advance. Does that sound right
 
I would very much appreciate your advice
I have a 671 blower on a 392 cu. in. hemi with 2 #1405 650 cfm Edelbrock carbs. These are the changes I made to the carbs: Primary jets - first tried .101 (#1429), now running .104 (#1430). Secondary jets - .101. Metering rods - first tried .070 x .042 (#1450); these did not give me the idle speed that I wanted so I went to .068 x .042 (#1446). I'm still thinking about going to a smaller diameter on the .068 side. Started with orange step up springs, now running pink. Changed needle and seat assemblies to .110 #1466).
 
Update:Was also told that blower engines need 12 to 20 degrees inital timing. Total at 30 to 32 degrees. I have a mag distributor and no vacuum advance. Does that sound right
That sounds right.
 

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