i just put a 600cfm carb on my 383 and was test driving it. it is tune from the factory to be pretty close to the right tuning. i took it out and tried gunning it from about half trottle to full and there was not really an increase in speed or rpm(i think i dont have a tach) why is that? could the secondarys be not tuned right?
2006-10-16 13:25:08 · 7 answers · asked by John M 2 in Cars & Transportation ➔ Maintenance & Repairs
try setting your choke pulloff...if it is not functioning correctly it won't let the 4 barrel open. the choke has to be open all the way before the secondary will open.
2006-10-16 13:30:57 · answer #1 · answered by Kenneth S 5 · 0⤊ 0⤋
Assuming you have a Holley it's probably the secondaries (like many others have said). If it a mechanical secondary, you need to tweak the secondary linkage to open further/faster.
If it a vacuum secondary you may need a different (lighter) secondary diaphragm spring. They are color coded and come in a kit of about 7 -if I remember right. (Holley Part #: 20-13)
You need a lighter spring in order for the secondaries to open faster. There is a chart on the back of the package that describes the springs, if I recall, the lighter the color, the lighter the spring.
It's not a hard swap, just don't loose the little check ball in the diaphragm housing when you disassemble it!
If the spring doesn't help, consider a larger (700/750) carb, especially if it has a larger cam and good exhaust. 383's like to BREATHE when you wind em up, that's what makes 'em such good motors!
2006-10-24 02:36:47 · answer #2 · answered by konstipashen 5 · 0⤊ 0⤋
choke pull off has nothing to do with power. It only kicks in the high idle on cold starts and keeps the engine from stalling when cold. Now this Holley you bought, is it vacuum secondaries or mechanical?. Now the Chryslers used carter AFB carbs on their engines, and if i'm not mistaken, it is alsmost the same cfm rating as that ol Holley carb. you just bought. Sop why would you feel more power? Now if you changed the rear gear ratio and added a 750 double pumper on top of a dual plane aluminum intake, then you would have a kick in your pants.
good luck..........
2006-10-16 20:36:42 · answer #3 · answered by mailbox1024 7 · 0⤊ 0⤋
It sounds like the secondarys are not opening up. In order to change that if that is the problem is to bend the linkage rods with a pair of needle nose pliers
2006-10-16 20:35:56 · answer #4 · answered by Danno 2 · 0⤊ 0⤋
if you have this 383 mated to an auto trans with a trottle contolled kick down cable maybe it just needs to be adjusted to kick down sooner or was not conected at all.
2006-10-16 20:42:41 · answer #5 · answered by lem604 2 · 0⤊ 0⤋
IF your motor is ok , replace carb ,if it is factory set ,you only need ,fast idol adjustment. remember power comes from the drive train / transmission . SPEED KILLS.
2006-10-24 19:29:40 · answer #6 · answered by john d 1 · 0⤊ 0⤋
Your secondaries are not opening.You need to adjust your linkage.
2006-10-22 16:33:20 · answer #7 · answered by George K 6 · 0⤊ 0⤋