carb and manifold question

[onebadmopar]

i have the performer 383 manifold catolog number 2186 on my 383 im also using the performer 1411 750cfm carb the manifold came with an adapter plate #2732 is this needed?

[firefighter3931]

i have the performer 383 manifold catolog number 2186 on my 383 im also using the performer 1411 750cfm carb the manifold came with an adapter plate #2732 is this needed?

The adapter plate should be used to help seal the carb to the intake manifold properly. The performer has a spreadbore flange and the 1411 has a squarebore baseplate. Use the adapter or you will have a vacuum leak. 



Ron

[onebadmopar]

i guess that explains why it seems like we hear air just as you step on the throttle and it stumbles could this give me a rich condition too?

[firefighter3931]

i guess that explains why it seems like we hear air just as you step on the throttle and it stumbles could this give me a rich condition too?

A leaking baseplate (vacuum leak) will cause the engine to go lean. If it's rich that is another issue. 


Ron

[onebadmopar]

put the spacer plate on and it helped still tho when ya start out on the throttle it feels like it wants to die if ya mash it quick it evens out and goes ok  at idle its fine just under initial load it stumbles

[firefighter3931]

Check your ignition timing and if using vac advance make sure it's plugged into ported vaccuum....very important !!!

I usually disable the vac advance and tune w/o it 

Bump the initial timing up to 12-15* at idle and check it at full advance. Ideally you want 36-38* all in by 2800-3000 rpm. 



Ron

[onebadmopar]

i think i managed to get it so it isnt so rich now but still the carb still seems a bit hesistant 1st off when we broke it in it had  a pinched line at the gas tank we thought line was clogged what we did was pour a little down the carb throat to try and suck some gas up what happened was it back fired thru carb a little small ball of flame we stopped then and checked out lines found that the line from  gas tank had gotten pinched off we then proceded to do break in all seemed  fine shut it donw and my buddies left i started it again and it ran like crap i shut it off and could see carb filling with gas i removed the carb and found a bad gasket in the carb put it back on and this is when  we noticed it being rich is it possible acclerator pump is bad too icouldnt tell by looking at it but it looked ok this was a brand new edelbrock 1411 750cfm with electric choke the choke seems to be working fine this motor is a 1967 383 2bbl to my knowledge it was built completely stock with what ever parts the engine builder got everything from  only exception to this is they did have to bore the cylinders 30 over  cam is stock stock lifters rods everything aluminum intake from edelbrock  hedman headers think maybe the carb is  to big for this motor? im at wits end its drivable but its a dog

[onebadmopar]

well friends came over tonight everything is spot on timing good vacum no apparent leaks all in agreement their is either dirt in carb or something happened to it when we had that backfire thru the carb 

[firefighter3931]

Borrow a carb from one of your buddies....one that is a known "good" carb and test it out. 

Where is your timing set ? at idle ? total degrees of advance and at what rpm ?



Ron

[onebadmopar]

timing set at 12 before it advances to about 36-37  runs much better but carb is responding very sloppy

[firefighter3931]

timing set at 12 before it advances to about 36-37  runs much better but carb is responding very sloppy

Did you set it with the vac advance hooked up ?


Ron

[onebadmopar]

no we disconnected the advance and plugged up hose

[firefighter3931]

no we disconnected the advance and plugged up hose

Did you leave it disconnected ?


Btw, your timing looks fine. 


Ron

[onebadmopar]

no we hooked it back up but we did take an allen screw and unwind it 8 turns no difference
is it possible carb is to big  for this motor?

[firefighter3931]

no we hooked it back up but we did take an allen screw and unwind it 8 turns no difference
is it possible carb is to big  for this motor?

When you hooked it back up which port did you install the hose in....that makes a big difference.

Personally, i never use vac advance....too much headaches. I would block off the port in the carb and leave it disconnected and take it out for a drive...see if it runs better.


Try that and report back.

The 750 should be ok on that motor...



Ron

[onebadmopar]

originally had it in the drivers port but then read its suppose to be in the passenger port .... made no difference

[onebadmopar]

well pulled carb apart .....found a dead beetle in it it was trapped in the opening where the choke plate is it was stuck under where the butterfly pivot is dunno if this caused my problem but i sprayed carb all out with cleaner and reinstalled is better still not 100 percent tho but that could be just tuning the carb now