67 Fury 440 Engine Problems

[SportFury70]

Hi Everybody,

Here we go again with having more problems with the car now. Today we decided to get it out for the year to get it ready for a show this coming weekend, and we noticed a small leak coming from the back of the underneath of the valve cover. This was not there when we put the car away last year. We decided to get it out anyway, and my stepdad decided to play with and advance the timing on the car then take it for a spin around the block…. Well, in my opinion that was a mistake. We took it around the block and it ran great, until my stepdad really laid into it and put his foot to the floor. When he did that the car started to sputter, pop, bang, and misfire. I even said what’d you do?! to him. We got it back home and he fixed the timing back to where it was before he messed with it the first time, then he decided to take it for another ride…. well this time it wouldn’t even make it outta the driveway without popping and banging so we put it away and let it cool off for awhile. After we let it cool off, we took the plug wires off and they looked normal and good EXCEPT for one. One of the plugs was really loose and was only finger tight so I’m personally thinking that this is the only problem, but my stepdad thinks differently and thinks that its something electrical and ignition related. As I said, its always somethin with this car. My stepdad says that the car has not brought him joy since he got it on the road and that he’s really ready to just take the stroker motor out and put a regular 440 in it. I don’t wanna give up hope on it, because I think its just something simple but I really don’t know anymore. Does anyone think differently than me or my stepdad? Tomorrow or the next couple days, we plan to tighten the spark plug then take it for another ride to see what it does.

 

[CBODY67]

Tighten the spark plugs, ensure the wires are routed correctly, the timing is where it needs to be, PUT SOME NEW GAS IN IT, and take it on a CRUISE of about an hour or so. NO WOT, just part throttle. I suspect that might cure the problems mentioned.

Why should the stroker motor be any different than the stock 440? Except that it hadn't been jacked with?

Just some thoughts,
CBODY67

 

[Northcoast300h]

Sounds like the timing chain jumped a tooth when WOT was applied, but the timing chain would have to be so loose it would be impossible to time.

Could also be your coil, points, or ballast if you have one. I changed to an electronic ignition, removed the ballast and used the stock coil...mistake. It ran great when cold but if I took it out on a long drive, it would start to sputter and pop. The third time I took it out, the mufflers exploded with a big BOOM. My coil looked like it was melting. I let it cool off, fixed the melted wires attached to the coil and limped it the 5 miles home. I replaced it with a low ohm coil, no ballast and its been running great. That was over 10yrs ago.

 

[SportFury70]

Ok, I have an update. The car still runs horrible. My stepdad worked on the car. He says he tightened the loose plug then made sure all the rest of the plugs were good and tight, then he took it for a ride. The ride was good, until he decided to turn around and go home. He turned around and it died on the side of the road. Then when he went to restart it, it turned over slow and hardly wanted to start. He gets it started and the carburetor is on fire. He blows it out then brings it home and put it in the garage. This is all I remember him telling me. He says he’s done with it… the engine I mean, NOT the car. He says he’s so angry with it he’s going to take the stroker engine out, and put the stock engine in. His friend Rob (or @1968Chryslers) and I are trying to convince him to keep it and find out whats wrong, and that another friend of Robs can maybe come over and look at it. My stepdads other friend Kevin (or @jetboy) also offered to look at whats wrong with it. Does anyone else know what could be wrong with it?

 

[CBODY67]

Carburetors don't catch fire just by themselves. Probably need to start with the ignition system. Making sure all of the plug wires are routed to the correct cylinders and there is no possibility of cross-firing or carbon tracks inside the distributor cap. THEN making sure the base timing is close to what a normal 440 would be (in the realm of 10 degrees BTDC, typically), all things considered, rather than what "somebody" said it needed to be. In other words, getting things back to basically "stock" in order to get a baseline level of things.

The carb certainly needs to be looked at! Float level is ONE area, for sure. Uncle Tony has a recent video where he talks about Carter 4bbls having an issue with sharp left turns, in their design DNA. Making sure the basic systems are adjusted correctly, as a baseline. Jetting differences with the stroker motor are a separate deal. Just make sure the carb is working as designed and not modified in that orientation.

Once these things are determined to be good, THEN progress with the fine tuning for best drivability. NOT WOT performance, just driving around normally. Little increments rather than otherwise.

If the ignition is electronic-converted, and it is "Chrysler-sourced", might try a new (normal version, not "orange" or "chrome" Mopar Perf) control box to rule out that issue. Check the internal electronic guts to ensure they are all adjusted correctly and such, too.

Please keep us posted on your progress,
CBODY67

 

[FURYGT]

Just curious, was a new gas tank and sending unit installed when the engine was put in? Has fresh gas been put in the tank? When the carb caught fire was there a pop or backfire from the carburetor?

I just replaced the tank, sending unit sock and fuel filter as the original tank had debris in it and the sock was deteriorating.

 

[SportFury70]

Just curious, was a new gas tank and sending unit installed when the engine was put in? Has fresh gas been put in the tank? When the carb caught fire was there a pop or backfire from the carburetor?

I just replaced the tank, sending unit sock and fuel filter as the original tank had debris in it and the sock was deteriorating.

Hi Bill, yes a new tank and unit were put in when the engine was. Fresh gas was put in last year when we put the car away, like we always do every year with our cars. There was a pop or backfire from the carburetor yes. We don’t use socks in our tanks. I just do NOT understand how your engine runs so good, and ours runs absolutely terrible when they were built by the same person at the same time.

 

[SportFury70]

Correction on my post 184: my stepdad says he retarded the timing on the car before he originally took it out for a ride.

 

[SportFury70]

Carburetors don't catch fire just by themselves. Probably need to start with the ignition system. Making sure all of the plug wires are routed to the correct cylinders and there is no possibility of cross-firing or carbon tracks inside the distributor cap. THEN making sure the base timing is close to what a normal 440 would be (in the realm of 10 degrees BTDC, typically), all things considered, rather than what "somebody" said it needed to be. In other words, getting things back to basically "stock" in order to get a baseline level of things.

The carb certainly needs to be looked at! Float level is ONE area, for sure. Uncle Tony has a recent video where he talks about Carter 4bbls having an issue with sharp left turns, in their design DNA. Making sure the basic systems are adjusted correctly, as a baseline. Jetting differences with the stroker motor are a separate deal. Just make sure the carb is working as designed and not modified in that orientation.

Once these things are determined to be good, THEN progress with the fine tuning for best drivability. NOT WOT performance, just driving around normally. Little increments rather than otherwise.

If the ignition is electronic-converted, and it is "Chrysler-sourced", might try a new (normal version, not "orange" or "chrome" Mopar Perf) control box to rule out that issue. Check the internal electronic guts to ensure they are all adjusted correctly and such, too.

Please keep us posted on your progress,
CBODY67

Thank you for the information, I appreciate it. The car is on its 3rd carburetor, 2nd electronic ignition brain, and I believe 2nd coil. The car currently has a Demon carburetor on it, and a blue Rick Erhenberg brain in it too. I unfortunately do not know the cfm of the carburetor though. The cars wiring and distributor is also all brand new from what my stepdad says. I will ask him what else is new on it and what else was done. He says he’s not putting anymore parts in it though. I’m just tryin and really want to save this engine because of all the time and especially money spent on it, but my stepdad says he’s had it with it. He says he sold his Dodge HEMI Magnum because it gave him so much s***, but nothin compared to this car and he would rather have that car back. At this point, I don’t know whats next. I just hope its a simple, and easy fix so the engine can stay in the car. I will update on what he decides and if it gets fixed.

 

[FURYGT]

You should use a “sock” (filter) on the fuel sending unit. Today’s ethanol gas turns to crap after 3 months, even with a fuel stabilizer. Once the source of what caused the carb to catch fire, try running the car off of a gas can with fresh super unleaded and see how she runs.

I assume that the coil is a performance coil vs a stock coil.

 

[CBODY67]

Thanks for the information. There are THREE level of Demon carburetors, with the Street Demon being the most common one for street use. That one looks like an updated ThermoQuad. The other "Demons" are related to more serious performance orientations. I'm not concerned with the size (cfm), just the type of Demon.

With the repeated changes of several similar items, I'm getting the suspicion that some of his "advisors" might not know as much as they perceive they might. Just as observation, no more no less. Which means the engine itself is not causing the problems, it's what is bolted to it and the way it all was installed. I commend you for trying to help him, but it might well be that that point has passed.

Putting the orig 440 back in, I suspect, will have issues, too. So that option is not a good one, either. I understand your orientation on the financial end of things. It would be much less expensive to take a measured and methodical approach to determining why the new motor does not run well. Which can ALSO get into the cam, heads, intake, and such for the stroker motor, which are "choices" that might have been sub-optimal at best. IF you can dig that information out, that might help, too.

Just some thoughts,
CBODY67

 

[FURYGT]

Thanks for the information. There are THREE level of Demon carburetors, with the Street Demon being the most common one for street use. That one looks like an updated ThermoQuad. The other "Demons" are related to more serious performance orientations. I'm not concerned with the size (cfm), just the type of Demon.

With the repeated changes of several similar items, I'm getting the suspicion that some of his "advisors" might not know as much as they perceive they might. Just as observation, no more no less. Which means the engine itself is not causing the problems, it's what is bolted to it and the way it all was installed. I commend you for trying to help him, but it might well be that that point has passed.

Putting the orig 440 back in, I suspect, will have issues, too. So that option is not a good one, either. I understand your orientation on the financial end of things. It would be much less expensive to take a measured and methodical approach to determining why the new motor does not run well. Which can ALSO get into the cam, heads, intake, and such for the stroker motor, which are "choices" that might have been sub-optimal at best. IF you can dig that information out, that might help, too.

Just some thoughts,
CBODY67

CBODY67,

To give some history, SportFury70’s step dad and I have been friends for over 40 years and we both had our 520 stroker’s built at the same time by the same engine builder, Comp-u-flow. My stroker was built to appear stock and be able to race in a stock appearing series. The step dad went with aluminum heads, intake and headers and has a slightly higher compression ratio. When step dad first installed the engine he had all kinds of issues and it took a lot of parts changing to figure out the problem, which was a bad Mopar Performance distributor, which was replaced by an Eherenberg distributor and high output put ignition module. All of the parts and carb swaps took place years ago and the car was running fine. I appreciate your help on this.

 

[SportFury70]

I assume that the coil is a performance coil vs a stock coil.

The coil thats on it now is a stock one from what I remember

 

[Rainy Day]

Fuel air and spark.. we need not over complicate a simplistic system.. have step dad run compression test, are all holes within 10% of each other? Is coil putting out good hot spark? are fuel lines and pump flowing steady and no restriction, is fuel pump push rod to short. You keep referring to hot start or not running well when warm is fuel line close to headers/intake. Does carb fuel soak? Slow cranking could be a multitude of things from weak battery, dirty connections bad ground on stater relay ect. Help us help you.

 

[65CopCar]

I would be verifying timing. First check that the pointer is accurate. The timing could be set way different than you think. To cover all bases, make sure the wires on are the correct spark plugs. Then I would degree the cam to make sure the timing chain did not jump.

Really sounds like ignition/timing to me.

 

[FURYGT]

Fuel air and spark.. we need not over complicate a simplistic system.. have step dad run compression test, are all holes within 10% of each other? Is coil putting out good hot spark? are fuel lines and pump flowing steady and no restriction, is fuel pump push rod to short. You keep referring to hot start or not running well when warm is fuel line close to headers/intake. Does carb fuel soak? Slow cranking could be a multitude of things from weak battery, dirty connections bad ground on stater relay ect. Help us help you.

I spoke with the step dad last night and he is going to check the coil. The fuel lines are not close to the headers and the plug wires have heat shields at the plug ends.

Checking the fuel pump pushrod is a good idea. FYI, the engine can't have more than 300 - 500 miles on it.

 

[65CopCar]

I spoke with the step dad last night and he is going to check the coil. The fuel lines are not close to the headers and the plug wires have heat shields at the plug ends.

Checking the fuel pump pushrod is a good idea. FYI, the engine can't have more than 300 - 500 miles on it.

Normally when running out of fuel, motor just loses power. DAMHIK. I have never seen it cause carb backfires. I have never seen a bad coil do that either, but I suppose it can. My experience with bad coils when the work they are fine then with heat engine just dies. Restarts after coiled cooled down.

I can probably compete with anyone on how many carb backfires and carb fires I have had in my race car over the 40+ years I have owned it. I don't anymore because I am much better at covering the basics.