Nylon-toothed timing gear.

[6thGenImperial]

While the 318 was commonly equipped with the cursed nylon-toothed timing gear, I am wondering if Chrysler's attitude around the Imperial was a little better. Since they went to so much effort to basically offer the best they had, does anyone know if this extended to the engine, and perhaps it was spared the leisure suit version of a timing gear? I mean, they got 360 heads and a unique version of the 360 intake. Or were run-of-the-mill short blocks the same for the Imperials too? I will have to know before I do much driving on my recent acqusition. That time bomb is in my mind. Had one come apart on me in my dad's '84 Ramcharger a few years ago. That 318 sounded like it had about 5 cylinders, but it got me home. Bent most of the pushrods, 3 valves, punched thru 2 rockers, but she still got me home. I was stunned when I pulled her down and saw what had happened. I vowed to NEVER run one of those cursed sets in anything I own. They're only a money saver til they grenade, and let's be clear, it was purely to save money. I know the story was to reduce noise. Really? Did the 360 get the same treatment? Pathetic excuse, but even a few cents per unit turns into millions saved in a company that was struggling. And once they went to the late 80's EFI, they all got nice wide metal sets because they HAD TO maintain tight timing to meet newer emissions requirements and coordination with the EFI. Not a peep about the noise. BTW, with new parts, that RC engine runs better than ever now.

 

[FredMcJoe]

This page over at imperialclub states what was advertized, that drivetrain components were pre-selected for use in Imperial. I recall seeing photos of the special stamp they put on starters, alternators, etc for use in Imperials. I believe the components with the highest build quality tolerances got the Pentastar stamp... I think it was a Pentastar... maybe someone else here can dig up those pics.
This webpage confirms the practice in the 2nd column over- http://imperialclub.org/Articles/81-83WPC/Page07_reg.jpg

 

[FredMcJoe]

Also, note Imperial EFI troublepoint #8 regarding slack timing chains.. 1981-1983 Imperial General Information

 

[6thGenImperial]

I figure I will be hanging upside down with a pen light trying to see thru the manual fuel pump opening in the timing cover to see if I can get a glance at the gear before I'm satisfied.

 

[FredMcJoe]

ohhh... always install always install new timing set... did I mention always install new timing set?

 

[6thGenImperial]

The seller stated approx 26,000 miles, but I don't trust those mugly others. No better than a timing belt.

 

[FredMcJoe]

I install a new timing set with every new mopar I get. They run so much better with a fresh chain and cogs. I get full steel sets, no nylon.
One night, a '72 Newport with factory optioned 440 died as I let off the gas on a freeway exit ramp. The nylon gears were all torn up upon inspection. 126k miles/30 years old at the time. New timing set ended the problems of surging at speed, oil burning, and fouled plugs. A wise investment.

 

[6thGenImperial]

I am a believer in excess capacity, so I always use full double-roller sets. Overkill for a stocker, but in my mind, too much is just right.

 

[FredMcJoe]

Does the odometer have "the asterisk"? http://imperialclub.org/Repair/Year/1981-1983/Retrofit/Pictures/ASTERISK.jpg

 

[6thGenImperial]

At the moment I cannot get the dash to illuminate, but I was looking around in there and it appears the pink power lead is loose. I kinda got side-lined recently and haven't been able to tinker, but it should not have the asterisk since it was never converted to carb.

 

[FredMcJoe]

A lot of clusters were needlessly replaced due to poor ground connections. When they installed a replacement cluster, it came with the asterisk circuit 'on', as I understand it. The repair links have more info on that kind of stuff if u backup the URL root. Neat car you have.. KYB shocks on my Volare Premier wagon turned it into a backroads burner. Super Six slant 6 with new timing set

 

[6thGenImperial]

Thanks. I kinda stumbled onto it, and probably shoulda just gone about my bidness, but the low mileage, overall basic familiarity of running gear, and price pulled me in. Don't often find a 33 yo car in this condition. Man, Slant Six. That'll last forever.

 

[FredMcJoe]

back to your question... the intake manifold is the same as a carb 318. The gasket that the TB sits on there at the intake manifold is a common vacuum leaker and a new one should be a regular maintenance replacement item if you're keeping it EFI. They won't run if they lose much vacuum.
Special to the Imperial were engines, transmissions, rear axles, and ancillary components. This page from the brochure shows how they were given special attention and used thicker body panels http://imperialclub.org/Yr/1981/Brochure/81brochure2Jmd.jpg
They screwed down the body parts like the engineers wanted them, no doubt they are the best build quality FMJ cars (except for the doomed EFI, of course). I presume the engines were selected for the best balanced crank assemblies and should be duly stamped by the engine block number, likewise for the other large components.

 

[Aspen500]

I'd almost be willing to bet it has a nylon tooth timing gear unless the timing set has been replaced at some point with aftermarket parts. They didn't use them for cost reduction, it was for noise reduction (that was the reason given anyways) and being an Imperial............ That said, I've never really noticed any difference in noise after replacing a nylon sprocket with steel. If you had them side by side, maybe you'd notice it.

The EFI wasn't a bad design or poor quality. The problem was electronics technology of the time wasn't exactly the greatest yet. That's what happened to the electronic sequential port injected '58 Chrysler's, excellent design and actually WAY ahead of it's time but,,,,,,,,,,,,,,,,,1950's electronic components were know to fail on a regular basis.
The one, and only one of the original 50 built that has the EFI on it only runs because the guy reverse engineered the control module and used modern electronics and I guess it runs like a charm.

 

[FredMcJoe]

LOL @ 500" Super Eight
We SuperSixers don't have piston envy.. really... we don't.....

 

[Aspen500]

LOL @ 500" Super Eight
We SuperSixers don't have piston envy.. really... we don't.....

LOL, you saw that Kind of a lie because the original was a E24 90hp 225, definately NOT a Super Six.

This may not be an absolute but the only Mopar engines I've run across with steel cam sprockets, that have never been opened up, were a 340 Challenger and a 360 4V from a Duster 360. Both were dual roller timing sets. I'd think engines like a 426 Hemi, 440-Six Pack, etc probably would have steel cam sprockets as well, most likely double roller.

 

[FredMcJoe]

Man cannot breathe by one barrel alone.

 

[Aspen500]

Man cannot breathe by one barrel alone.

Neither can an engine. Got SMOKED by my buddies wife in her stone stock '67 Camaro 250 with a 3 on the tree back in the late '80's. Can you say embarrassing? lol

 

[FredMcJoe]

the control module and used modern electronics and I guess it runs like a charm.[/QUOTE]

Well, the EPA wouldn't budge on a rule of their's. They wouldn't allow Chrysler to let the system reach a certain ppm of one of their regulated emissions. They required Chrysler to have a 'shut-down' feature built into the module so that if it got too rich at the O2 sensor, it would trigger the limp-home mode. There is also a ..I want to say stepper motor that controls fuel pressure that was of lower quality, a modern replacement has been discussed on the Imperialclub.com mailing list (searchable). Then there is the sealing of any and all vacuum leak areas down to the air cleaner lid gasket. I wondered if a voltage limiter couldn't be put inbetween the O2 sensor and the computer to block the high ppm readings that triggers the 'shut-down' limp home mode, but I'm no elec engineer. There is so much right with these cars that make fixing the wrong things worth it... <<< opinion

Then we can talk about the sagging front K-frame subframe problem.

 

[6thGenImperial]

I'd almost be willing to bet it has a nylon tooth timing gear unless the timing set has been replaced at some point with aftermarket parts. They didn't use them for cost reduction, it was for noise reduction (that was the reason given anyways) and being an Imperial............ That said, I've never really noticed any difference in noise after replacing a nylon sprocket with steel. If you had them side by side, maybe you'd notice it.

The EFI wasn't a bad design or poor quality. The problem was electronics technology of the time wasn't exactly the greatest yet. That's what happened to the electronic sequential port injected '58 Chrysler's, excellent design and actually WAY ahead of it's time but,,,,,,,,,,,,,,,,,1950's electronic components were know to fail on a regular basis.
The one, and only one of the original 50 built that has the EFI on it only runs because the guy reverse engineered the control module and used modern electronics and I guess it runs like a charm.

Not to lock horns with ya, but I don't buy the noise excuse, because the 360 didn't get the same treatment. The 318 was the base pedestrian engine, typically expected to not exceed 4,000rpm in most instances. a nylon set is the cheapest thing to run. The 360 was aimed primarily at the work truck/heavier duty crowd. They're gonna afford more gas and added costs because it's the price you pay for the added cubes, and this was when gas wasn't even a buck a gallon, but Chrysler was in a death spiral. I suspect it has nylon, cuz outta sight outta mind, and with the final drive ratio and low HP, it wouldn't be loaded with undue stress. It'd last 40K miles, maybe more. Will have to post when I get into it.