73 Charger - Timing Chain

[FLASH80]

Greetings Charger Friends,

Dealing with a continued issue setting the timing on the '73.   Engine is 400.   It's got a edelbrock 750 performer series,   4barrel carb and presently we're blowing flames through it on occasional start-ups.   Needless to say, it's starting really hard and I'm calling edelbrock's tech support line back.

That being the major issue... I have been suspicious of the timing chain and one of the things on our list is to replace the timing chain.   I found one listed on Paddock parts and was wondering if anyone had any particular experience with this replacement part.     

Name:   66-74 DODGE/PLYMOUTH REPRODUCTION TIMING CHAIN SET   SKU:     3501SA  

Any tips or suggestions are very much welcome.   Fireballs look all cool, but damn, gas is expensive and this thing's a beast anyway!

[Ghoste]

I would suggest going to high quality double roller set.  If there isn't a speed shop near you or the local parts jobbers can't supply a true roller replacement, then order it from Jeg's or Summit.

[cudaken]

 Flames, out of which end?

Have you checked the chain for slop or if it has jumped timing?

I like the MP Chain.

                                  Cuda Ken

[Ghoste]

You didn't have the distributor out did you?

[FLASH80]

Flames through the top of the carb, out through the newly singed hole in the air cleaner.  ;-/ 

I haven't checked the chain yet but it just seems like a likely suspect and a good idea to knock it off the list by replacing it with a new/upgraded one... I don't know about specifications for these things, so I was thinking "stock" was the way to go, but I'm completely open to suggestions.

Thanks!

[FLASH80]

The distributor is in.  This just happens when it won't start and won't start and suddenly, Whoosh, a wannabe car-b-que! I should get out the marshmallows and have a party, or at least video tape it for a segment of stupid human tricks... ;-)

[Ghoste]

Sorry, I meant did you have it out and then put it back in before this problem began?   It could be out of synch.
First thing to do is make sure the rotor is pointing to number one when that cylinder is at top dead center on it's ignition stroke.   Then you need to check for slop in that chain.   Pull a valve cover and rotate the engine manually until you see a valve just begin to move.   Then rotate it the opposite direction until the same valve begins to move the other way and note how far you have to rotate to initate the change in direction.
Stock replacement is not money well spent if you drive the car.   The chains stretch and the gears are usually nylon which is notorious for teeth breaking off.   This is a situation where you get what you pay for.

[cudaken]

 Flash, best thing to do is start with better details.

When did this start?

How many miles that you know of on the 400?

Had you changed anything, then the problem started?

Have you checked the timing?

Does it crank slow when starting?

How does it run when started?

Have you checked the Choke?

There are a lot of things than can cause a Carb back fire, what made you think it was a chain?

If you need a chain, I would use the Mopar Performances P5249268. It is a ture double roller chain and will out last a stock chain by 50,000 miles. I installed one and used it 62,000 miles, pulled that engine, checked the deflection and was only 3 degrees. In other words still good as new, used it in the new engine.

                                               Cuda Ken

[Ghoste]

Ken's right.  We're jumping ahead of ourselves here.

[FLASH80]

Wow, lots of questions but I will answer best I can...

Recently acquired the car, but based upon the blistered paint on the hood, it's not a new problem. Once it gets going, the engine is sweet.

Don't know about the actual mileage at all... but I am guessing +150k.

We've been working on the timing and... it's just not right.  I told my friend it's probably a matter of the fact that everything on the car is just that much out of spec to make it so any particular action doesn't give the expected normal result (if that makes sense).

The choke... ugh... this one is weird... or maybe just wired backassward:  The Edelbrock 750 is one with a manual choke.  You know, usually you pull out the choke to increase or open the fuel flow. Ehhh... not in this case... if the choke is pulled out, then that closes the choke. (Yeah, I'm like WTF, but we just got this and can't solve "everything" simultaneously, so it's backwards for now). 

Not thinking that it's necessarily the chain that is the whole problem with this backfire issue, but I think it sounds like a fundamental part that could bear replacement, thereby, bringing one item to a reliable operating standard, as in works as advertised.  Once that is done, and perhaps aligning/synchronizing the distributor, then perhaps, if the problem is still happening, the edelbrock guys will have something relevant.  We've already re-jetted/metered the carb... but now I have to go get a new air cleaner (a filter or two) since my firebreathing dragon has done a beautiful job on the one that's in there...

But... this and all the other little issues aside, I do love this car.

[BrianShaughnessy]

It's entirely possible you have a motor with one of those old crappy nylon gear timing chains.   Probably best to get rid of it since you think it's got that much mileage.

Take a look at 440source's page...  many options to choose from.   Not that you have to buy from them either for that matter.  http://www.440source.com/timingchains.htm

[cudaken]

The choke... ugh... this one is weird... or maybe just wired backassward:   The Edelbrock 750 is one with a manual choke.   You know, usually you pull out the choke to increase or open the fuel flow. Ehhh... not in this case... if the choke is pulled out, then that closes the choke. (Yeah, I'm like WTF, but we just got this and can't solve "everything" simultaneously, so it's backwards for now).   

That is the way it should work. Pull it out and close the choke. When you said timing is not acting right, is it jumping a round? What is the timing sat at idle? Mine like's 10 BTDC.

Going to guess you are not in the USA either which is fine, just got a call from Belgium little while ago.

Sound off hand the engine is starting to lean. Not a Edie fan, but on Holleys found about 1/4 inch open choke works best.

Does it back fire as soon as you crank it or when you try to give it some gas still cold to get it off idle?

                                 Cuda Ken

[Chryco Psycho]

put a breaker bar & socket on the crank & rock the crank back & forward , you will feel the extra load as the cam is turned , see how many degrees of slack the chain has now

[FLASH80]

  Pulling out the choke to close it is how it's supposed to work? Yikes... counter-intuitive.

Sorry, I don't have the specs on what it is currently set at but when we originally got the car, it started like a champ, but to describe the idle... it wasn't smooth, it was sortof "surging".  So, that's why we started trying to tweak the timing, which you think would be simple.  Anyway, the idle is now smooth, when it's running, but the car is really hard to start.  The backfire occurs after trying to start it a few times, I'm guessing excess gas is in the carb and then it ignites...so not immediately but we're talking 8 inches of flame... very hollywood fx.  When that backfires, with the requisite BOOM, the choke blows closed.  Quite a phenomena. It will start though.  Just takes way too long and let's be real, you look like an idiot out in public just turning the motor over, "rrreearrrreeaaarrrrrearr, rrreearrrreeaaarrrrrearr, rrreearrrreeaaarrrrrearr," over and over again.   

What can I say... I'm not too mechanically inclined... yet.  But I am learning as time permits. Thanks a ton for the advice everyone, and the lead on replacement timing chains too.  I definitely don't want a cheapie nylon tooth one.

Once this is resolved, it will be back to unravelling the mess in the electrical.  And then one day, body work, paint and interior...

[cudaken]

 Sorry, I don't have the specs on what it is currently set at but when we originally got the car, it started like a champ, but to describe the idle... it wasn't smooth, it was sortof "surging".   So, that's why we started trying to tweak the timing, which you think would be simple.   Anyway, the idle is now smooth

Could the Charger have a cam in it, before you worked on it how did it run when it was off idle? Had a guy when I was 18 (Long, Long, Long time agao) told me he could make my 68 Runner idle smoother. He did, had the timing all F--ked up. Got my ass kicked by a 289 2 barrel when I took it for a drive, went back and retimed it the right way.

What did you do to make it idle smooth, just timing or did you play with carb as well. If the Charger as a cam in it it will idle bad. When I moved he my neighbor asked me what was wrong with the Runner, told him nothing just a big cam. He looked confussed.

                                   Cuda Ken

[The Mad Scientist]

Yup, a cam can sure do that.

A friend of mine put a camshaft from his outlaw dirt car into his El Camino.   That thing wouldn't idle for shit.   He had to stall the converter at stopsigns.   Which sucked because the cam threw manifold vacuum off so bad that the brakes were weak to begin with.  

But that Camino was fun to cruise in anyway.     

If anyone repops nylon cam gears then I don't understand how they stay in business!

I bought a Cloyes double roller for the 318 when it puked up the stock gear (lasted 29 years, not bad),  Before the slanty in Dad's Volare ate a cam gear it was showing 15 degrees of slack. 

I agree with everyone else.  Check your static timing first, then go from there with your tuning adjustments.

[Nikeajax]

Well fellers, I'm here now to answere the questions, I'm the one working on this car.  Um, when we first got the car, the timing was set at I'm guessing about 30-50 BTDC, or four-inches from top dead on the pulley.  The car would start, but it was only pulling about three to four-inches of vacuum, so I reset it at about 8+ -, and raised the RPM's, now I get about 12-inches; I could get more, but it feels like at that point, the RPM's are just too high: this is set when the vacuum advance is disconnected.  It still doesn't idle great, it has a miss in it somewhere that I can't find, indicated by the unsteady tailpipe.  The car has a stock cam in it, because the trick cam is in the trunk, in a box!  The monkey's wrench has really been on this car, oooook, oooook, now I have to fix it; people shouldn't be this abusive to a car!
That's all I can think of for now, thanks,
Jaybird

[cudaken]

 My first thought is a broken valve spring, worn out lope or a burnt valve. I am guessing at this point Jay you have checked the basic stuff like wires, plugs and cap.

Was the vacuume reading steady or moving around a lot? Have you checked on the chain slack? I had a 150,000 mile BB that had 11 degress deflection and ran great before I brunt a valve. That is when I checked the chain, while I was doing the heads. Sure helped out the bottom end.

                                            Cuda Ken