Thread: 454 Wacky Timing

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STILL TRYING TO GET THIS MOTOR LINED OUT, NOW I'VE GOT HER STARTING GOOD IDLING GOOD TIMING SET TO WHAT I THOUGHT WAS CORRECT BUT WHEN UP I REV IT UP AND TAP INTO THE SECONDARYS ON CARB IT WANTS TO POP AND MISS AND SPIT FIRE . FIRST CARB 850DLB PU. HOLLEY, SECOND CARB BRAND NEW 750 MAN CHOKE ELDEBROC. BOTH CARBS SAME DEAL, AND IT IS ONLY WHEN I TAP INTO THE MANUAL SECONDARYS ON THESE CARBS,SO I ADVANCED THE DIS. TIMING WAY FARTHER THEN I REALLY THINK IT NEEDS TO GO DON'T WANT TO SMOKE NO PISTONS BUT WITH THE TIMING WAY ADVANCED LIKE THIS IT SEEMS TO ACT LIKE IT WANTS TO DO RIGHT . ANY ADVICE?

Did you set the timing with the vacuum advance disconnected?

If not, the timing will be retarded.

Go here for a little more info.

http://www.clubhotrod.com/forums/sho...threadid=13909

YES CX9 I DID SET TIMING WITH VAC. ADVANCE UNHOOKED SET AT 32 DEG. STILL POPS ONLY ON THE SECONDARY SIDE OF CARBS IT HARD OFF IDLE AND JUST USE PRIMARYS AND DOES FINE STARTS GOOD IT IT HARD AND TAP INTO SECONDARYS AND POP /MISS /PUF SET THE TIMING WAY UP LIKE TO 45 DEG APPROX. AND IT WILL TAKE IT SOMETHING ISN'T RIGHT WITH THIS PICTURE.

You could also have the numbers 2 and 4 spark plug wires switched.

denny w how do you set the tension or adjust the opening of the secondarys on a holley 850 dual line double pumper? , 76 1500 I've quadtriple checked myself on the wiring of the plug wires. what I'm wondering is it possible that I may have the timing chain off one tooth I really don't think that this has happened but who knows.What I did to this motor is replaced the oval heads with a set of newer style square ports installed a 268 dur./542int./554ex 110 lobe seperation lunati voodoo cam,a gm factory dual plane highrise marine intake, a holley 850 double pumper installed 81 primary jets,and 84 secondary jets last night,carb had 76 primaries and 80 secondaries still same problem,foloats set correctly, air correct, can't find any vac. leaks changed coils on hei same problem changed plugs, same deal, I set the valves[hyd.] on the engine stand according to the chiltons manual proceeder, should't be to tight.

denny w how do you set the tension or adjust the opening of the secondarys on a holley 850 dual line double pumper? , 76 1500 I've quadtriple checked myself on the wiring of the plug wires. what I'm wondering is it possible that I may have the timing chain off one tooth I really don't think that this has happened but who knows.What I did to this motor is replaced the oval heads with a set of newer style square ports installed a 268 dur./542int./554ex 110 lobe seperation lunati voodoo cam,a gm factory dual plane highrise marine intake, a holley 850 double pumper installed 81 primary jets,and 84 secondary jets last night,carb had 76 primaries and 80 secondaries still same problem,foloats set correctly, air correct, can't find any vac. leaks changed coils on hei same problem changed plugs, same deal, I set the valves[hyd.] on the engine stand according to the chiltons manual proceeder, should't be to tight.

thanks denny w I'll check this out, because now I'm grasping for straws.

How about the centrifugal advance weights in your distributor? Are the set up right, and/or are they working properly? If they are stuck or set too tight, they may give you a severe retard situation even at speed. Just a thought; I may be all wet.

Try restricting the secondary air flow with your hand (wear a glove) and see if the popping decreases. It sounds like the secondaries are lean, or the spark is way retarded. Are you sure your timing marks are right?

Maybe I'm just a dumb old geezer, but it sounds like to me you don't have enough fuel pressure. Sounds like when you open the secondiares, it's leaning out. Check that out.

Originally posted by Oldf100fordman
Maybe I'm just a dumb old geezer, but it sounds like to me you don't have enough fuel pressure or enough fuel supply. Sounds like when you open the secondiares, it's leaning out. Check that out.