engine chuggin

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ramman7284

ramman7284

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ok i got my new carb on and adjusted out as best as i can out of the box. when i get it about quarter throttle in gear it starts to chug i need some pointer on to get it smooth. in a since i might b using to big of an intake for a stock 318 and it might b pinging when it chuggs
 
"my new carb" "too big"

We need some details. Hell I don't know are talking about a small bore 2bbl, or a Holley 3bbl!!!! or one of these:

sv1black1.jpg



So you have a stock 318. Headers? Dual exhaust? stock cam?

What exactly do you have for a manifold?

What is the exact model/ part number of the carburetor?

Any idea what your timing, and timing curve amounts to?
 
as far as im concerned its a stock motor as when i bought the car the guy didnt tell me to much about it just that it was stock and from a 68 p/u. i threw a mopar m1 intake stock exhaust manifold dual exhaust the carb is a 4776 holley 600. as for timing im not sure wat its at as i power timed it when it had a 2bbl dist is a vac adv mopar
 
I have no idea why you thought either of those was a good idea. An M1 is a high RPM manifold meant for a high performance engine, NOT a stock 318.

You can "get away" with a 600 cfm carb on a 318 IF it's a vacuum secondary type carb. A 4776 is not. It's a double pumper, which means that if you open all 4 barrels with your foot, there is nothing (vacuum) to limit, and it's WAY too big for an especially stock 318.
 
first thing you need to do is get the timing set correctly with a timing light...

alot of carb problems are miss timed engine....
 
well first i was told i wouldnt have a problem with that intake and carb but yes i do need to adjust the timing
 
I'm in the timing camp as well.........I think there's a good possibility that your over advanced, especially at part/cruise throttle using the vac advance. You really do need a light to get it in the 14* initial range w/o vacuum and go from there. You could always pull the vac line and plug it first to see if it's any better. That could confirm my over advanced theory.
 
Whether or not you agree with the carb application here, it should be irrelevant as too this issue. If it's occuring at light to 1/4 throttle, he won't be into the secondaries anyway. Minor jetting differences aside, it will act like any 600, (DP or Vac) on the primaries. As to the intake, is it the dual plane or single plane?

I'm sticking to my post #7, timing first!

I am however, curious if when you tuned as best you could out of the box, that you checked/set the float levels?

Just to explain my overadvanced theory from earlier, here's a senario.........Initial is at 20*+ and a vac can pulling in a lg. number hooked to ported vac....... It starts and idle's ok, but as you start to accelerate your bringing in the vac adv so now your approaching 40*. As the rpm's increase, the mech adv is growing and now your close to 60* and the engine just isn't liking it........just 1 of many possibilities.
 
The street avenger would probably work great on a stock 318. Tried one on my 340 with is not stock and it was all wrong!
 
OldmanRick said:
I'm in the timing camp as well.........I think there's a good possibility that your over advanced, especially at part/cruise throttle using the vac advance. You really do need a light to get it in the 14* initial range w/o vacuum and go from there. You could always pull the vac line and plug it first to see if it's any better. That could confirm my over advanced theory.
Click to expand...

Is that btc or after? Granted for this engine is older than the car as I'm told supposed from a 68 p/u
 
ramman7284 said:
Is that btc or after? Granted for this engine is older than the car as I'm told supposed from a 68 p/u
Click to expand...

That's BTDC ramman. When i saw it was power timed, more times then not it leads to too much advance. I may be wrong, just what it sound like to me. Gotta get a light on that badboy and check it with the vacuum advance disconnected and plugged.
 
As Dirty Harry once said, "A man's got to know his advance curve."
 
ok now i no you guys have been doin this for longer than ive been alive probably. would it matter if the engine is an original left hand water pump then changed to right hand?
 
ramman7284 said:
ok now i no you guys have been doin this for longer than ive been alive probably. would it matter if the engine is an original left hand water pump then changed to right hand?
Click to expand...

If your talking about the timing cover, early vs late, and the corresponding marks on the balancer, then yes, you will have a problem reading the timing marks.
 
well i switched it cause thats what was in the car and i didnt like the way hose was ran right under the crank pulley i changed the timing cover pump balancer and all i needed i was told it would work as long as the balancer was 90 degrees from the older one im just curious on what someone would say bout that
 
Not sure if i understand completely, but if your using the late cover with the marks cast in it on the drivers side and the corresponding late balancer, you should be ok as far as the marks lining up?
 
thats basically my question. and as far as my timing goes it was way advanced i got it bout 10 atc but started running rough and i think i may have to pull my dist and reset it cause my vac adv is almost pointing straight forward but ill have double check my setting since i wasnt the one that put that dist in
 
If you haven't checked the marks with a piston stop, you'll never know if they're accurate
 
ya i no thats actually wat im goin to do next when i get a chance and some light when i get home from work
 
When you say 10 atc are you talking after top dead center or did you mistype and meant 10 before top dead center. It should at least be 10 before top dead center.
 
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