440 only backfires

[Cody Gatlin]

hello I have a 66 charger with a 77 440 in it I just got it been sitting for who knows how long put plugs wires ready to run distributor ect. It backfire out the carb and exhaust im think maybe some stuck valves but just looking at some ideas it sat with no carb on i got it free and soaked with some marvel put a 90s dakota starter amd it turns over really good just cant get it to actually bust off and run any help would be appreciated

 

[Bad B-rad]

First place I would start is timing.
Maybe, plug wires installed incorrect, its easy to do, or your ignition timing is incorrect.

 

[Bad B-rad]

After you double check plug wires, and the timing, get friend to crank the car over(or a remote starter) and turn the distributer slowly.
Listen for the engine to try and start, if that has no effect, and you have made sure the distributer is not 180 degrees out.
Maybe pop the valve covers and check valves, are not stuck open.
Also MAY be carb issue dumping in too much fuel, but I would start with timing, and plug wires.

 

[diesel_lv]

I had fresh built motor, all new everything, followed every step. Backfired over n over. I'm rechecked wires, distributor, pulled valve cover to verify #1 3 different times. Still backfired. Then someone said it fires in counterclockwise rotation and I wan thinking, yes I know the distributor rotates counterclockwise. Then it dawned on me, wires get put in firing order counterclockwise too. I kept looking at a damn pic instead of laying them out counterclockwise. Fired up 1st try after that.

 

[440Coronet500]

As stated above, backfire through the carb typically means retarded timing. First, confirm proper order of plug wires. BB distributor rotation is CCW. Once that's confirmed, advance your timing using a timing light. A good starting point is approximately 12 degrees BTDC. 440'

 

[cheeseburgerhead69]

Set the balancer to TDC, pull the distributor out and verify that the oil pump drive is aligned correctly. it should be facing with one end facing the firewall and the other pointing to the radiator.

 

[Bad B-rad]

I was called in to get a new rebuilt 440 running, after a few GM guys gave up.
It was the timing, but what I found, and I think is funny was the distributer was 180 out, and the plug wires were installed on the cap so it would run 180 out!!!!
With the distributer being installed wrong, the vacuum advance was hitting something, I don't remember, not allowing the correct timing to be achieved.

I got a huge kick out of the wires on the cap, being installed WRONG, but yet correctly in order to get it to run, kinda,LOL.

 

[Cody Gatlin]

Okay I've tried messing with the distributor even took it out turned it 180 still same thing it gets better turning it sometimes but it builds up enough to just mainly gunshot out the exhaust I've double checked firing order

 

[Bad B-rad]

If your confident the distributer is installed correctly, so #1 on distributer is happening when the #1 piston is at TDC.

Pop off the valve covers, maybe you have stuck valves.

 

[Bad B-rad]

My 1969 Charger arrived to me with two stuck valves, and two bent push rods.
That car sat inside for 30+ years with hood on and carb installed and two valves were froze 1/2 open. So it can happen.

On my engine, I started by pulling valve covers before I even tried to start, just because it is the original engine, so before I tried to start, I wanted to check things out.

 

[Cody Gatlin]

If your confident the distributer is installed correctly, so #1 on distributer is happening when the #1 piston is at TDC.

Pop off the valve covers, maybe you have stuck valves.

That's what I was think I just wanted to make sure and rule out other possibilities bit im going to triple check firing orfer

 

[493 Mike]

Is the spark off the coil wire consistent while cranking? No cracks in cap or rotor? Pick up coil working properly?
Mike

 

[Cody Gatlin]

There's no telling im trying to make sure the motors good before I commit to it, im gonna pop the off soak it in marvel and see if I can break the rubber mallet out

 

[Cody Gatlin]

Is the spark off the coil wire consistent while cranking? No cracks in cap or rotor? Pick up coil working properly?
Mike

Brand new distributor coil wires plugs

 

[69Bee]

Unless you know the condition of the timing chain set, a "Silent" timing set (aluminum & plastic) could still be in there. When it deteriorates and falls apart, timing goes to ****...

 

[Cody Gatlin]

Unless you know the condition of the timing chain set, a "Silent" timing set (aluminum & plastic) could still be in there. When it deteriorates and falls apart, timing goes to ****...

I'm not sure about the condition

 

[Bad B-rad]

When you remove the valve covers, it should be very easy to see if you have any stuck or broken/bent parts.
If it all looks good, you should turn the engine over, by hand (or by starter, in your situation you have already cranked it with starter, so damage is done, if there is any) and watch, make sure everything is doing what it should. If at that point you find stuck valves, maybe then move on to the marvel mystery oil.

As 69Bee stated, the original single row "silent" timing chain could have missing or broken teeth, and your timing events are off no matter where you turn the distributer.


Imo If you find stuck valves, the head probably have to come off, you may have luck with the MMO, and rubber mallet, but you also may have other issues, if engine sat un covered, with no carb, and moisture got in to make valves seize in the guides, may be more headaches hiding else where.

 

[66Satellite47]

Didn't see anybody ask if the distributor is installed 180* off. Pull the valve cover off, watch the #1 intake valve as you turn the motor by hand, so as it closes you get TDC on firing position, see if the rotor is pointed to #1 in the cap. Otherwise timing chain may be off a tooth.

 

[Bad B-rad]

Didn't see anybody ask if the distributor is installed 180* off. Pull the valve cover off, watch the #1 intake valve as you turn the motor by hand, so as it closes you get TDC on firing position, see if the rotor is pointed to #1 in the cap. Otherwise timing chain may be off a tooth.

Post #3, LOL

 

[Don Frelier]

A compression test will tell you the engine condition.