popping out the exhaust

[rattlesnake]

After setting the timing last week and thinking it was gravy because it ran so good. I had a lot of problems with getting the choke adjusted right so I thought I might just remove it and see how it goes. After getting it set up I do not plan on driving it too awful much in the winter anyway. So it started right up yesterday but had a loud popping noise coming from the headers. Could this be a result of just being cold with no choke? I did remove the carb to take the choke off, so could a leaky carb flange gasket cause this?  I ended up monkeying around with the timing, even though I knew it to be correct before, did not seem to effect the popping. It was not consistent but seemed to be random.

[anlauto]

This could be unrelated, but years ago I had a car making a loud popping noise and was told it was a sticky valve

[brads70]

Sounds like an exhaust/header leak?

[72cudamaan]

I'm betting base gasket didn't re seal and now you have a lean condition. 

[HP_Cuda]

You retarded the timing too far and with a small gap in your exhaust (least path of resistance) your backfire came out via that gap.

Tighten up your manifolds and then you will have a real backfire through your carb!!! 

I'd advance the carb till you don't get a backfire or set the timing.

[cudabob496]

too much timing advance can cause backfire

[HP_Cuda]

that is true as well, he didn't say which way he went.

too much timing advance can cause backfire

[rattlesnake]

New plugs and a new carb base gasket did the trick. I must have dropped the #3 plug when putting it in and did not check it, the gap was mashed flatter than a pancake as in 0. Runs like a champ now.

[cudabob496]

New plugs and a new carb base gasket did the trick. I must have dropped the #3 plug when putting it in and did not check it, the gap was mashed flatter than a pancake as in 0. Runs like a champ now.

awesome!

[rattlesnake]

might have spoke too soon. Changed out the break-in oil today and then started the 440 up and guess what? pretty significant popping out the exhaust again. It did go away as the car warmed up and went away completely after total warm-up. What the crap?

[cudabob496]

might have spoke too soon. Changed out the break-in oil today and then started the 440 up and guess what? pretty significant popping out the exhaust again. It did go away as the car warmed up and went away completely after total warm-up. What the crap?

maybe the warming up sealed off a leak somehow?

might want to check ohm rating on your plug wires? when testing them with a probe at each end, move
the wire around to see if you have an occasional opening of the circuit.

make sure plug wires are not interfering with one another.

got a new distributor cap?

[Chryco Psycho]

are you using a choke , could be just lean while cold

[cudabob496]

misfiring?

make sure your electrical system is good.

[rattlesnake]

Thats what I am wondering, Chryco. No choke, I had to cut the choke body off as well as cut the vent tubes and breather post down to get hood clearance. It is cold (warmed up to 40 degrees today)in Indiana this time of year. If the choke is the problem, I am not sure how to get around that. I have no room for a choke body unless I change my intake.

Cudabob,
Plug wires are brand new, but I have new junk before so I will check them. As far as interferring with each other I have a really nice wire loom and the wires do not touch each other except at the distributor, but again I will check it. If it was the cap or the electrical system, wouldn't it act up when hot as well as cold?

My other concern is can it damage the engine by doing this during warm-up. I did notice tonight it must have run real hot, real quickly during warm-up tonight because it discolored a portion of one of my header tubes. I don't remember it being there before tonight after warm-up.

[cudabob496]

Thats what I am wondering, Chryco. No choke, I had to cut the choke body off as well as cut the vent tubes and breather post down to get hood clearance. It is cold (warmed up to 40 degrees today)in Indiana this time of year. If the choke is the problem, I am not sure how to get around that. I have no room for a choke body unless I change my intake.

Cudabob,
Plug wires are brand new, but I have new junk before so I will check them. As far as interferring with each other I have a really nice wire loom and the wires do not touch each other except at the distributor, but again I will check it. If it was the cap or the electrical system, wouldn't it act up when hot as well as cold?

My other concern is can it damage the engine by doing this during warm-up. I did notice tonight it must have run real hot, real quickly during warm-up tonight because it discolored a portion of one of my header tubes. I don't remember it being there before tonight after warm-up.

If its been a while, a new distributor cap and rotor can sometimes do wonders. At least check the contact points under the cap, and on the rotor, for corrosion, etc.

If engine running in place for a long time, put a box fan on high setting in front of car.

Is carb in good shape?