1972 roadrunner/gtx grille

JosephGiannini · Post by **JosephGiannini** » Tue Mar 13, 2007 12:33 pm

Also if you cant line up points when you weld.
I see poeple pay tons of money for things they could weld or tap.
Etc etc.
Also you be suprised how carbon fiber,fiberglass and steel are really close in weight.
Now as far as weight on my vehicle.
Since I reinforced the frame and suspension.
I am not really concerned with weight.
Import tuners are concerened with weight not b body drivers.
I am sorry this car is in the same class as a charger.
I dont think weight is an issue.
As long as you have th ehorsepower and driveline to push it.
But that is my opinion.
to have a floppy non-function spoiler.
isnt my cup of tea.
That is me.
If i want to mock up a grille out of steel.
I can how about that.
And guess what once i document all the measurements and all from
the grille .
I wil lbe able tomake as many as i want out of any material.
but i choose steel cheap to get easy to form etc etc

1bluegtx · Post by **1bluegtx** » Tue Mar 13, 2007 2:29 pm

JosephGiannini wrote: One if you are worried about weight dont
71-72 roadrunners weigh in at about 3400lbs

Need to add about 500 pounds to that!

BRIAN

Post by **Eric** » Tue Mar 13, 2007 8:30 pm

Well, I would be worried about hanging all that weight out in front of the front tires. Seems it would throw off the balance even more of a car that is already pretty weight biased to the front.
As for polymers being unsafe, I'm not sure where that comes from. As a grill, they are fine. How many cars (modern and from back in the day) have plastic grills??? I've not heard of one presenting a safety issue.
Again, this is just my opinion and what I would want. I'm interested in originality (at least a part that looks original). To each his own....

Post by **Eric** » Tue Mar 13, 2007 8:46 pm

1bluegtx wrote:
JosephGiannini wrote: One if you are worried about weight dont
71-72 roadrunners weigh in at about 3400lbs
Need to add about 500 pounds to that!

BRIAN

Road tests from back in the day listed a 383 auto 71 runner at 3750 lb. so a 340 car was probably a little less, a hemi 4spd car a little more....

JosephGiannini · Post by **JosephGiannini** » Wed Mar 14, 2007 1:28 pm

Ok here you go on polymers.
Any polymer that is used in fabric bond
Such as glass fiber or carbon fiber uses petroleum based
adhesives.

When a plastic material reaches ignition, the temperature at which it generates a volatile gas, it will burn easily. If the volatile gas is not burned it's a toxic hazard. The toxicity of plastics materials is covered in chapter 5. Since plastics are excellent insulators heat does not initially penetrate below the surface molecules. The flame, either external or supported by the plastic flammable gases, generates additional heating fuel which decomposes more plastic, generating more volatile. As long as the flame is present, the circular process continue until all material is consumed or until the volatile gas is terminated. Most plastics materials have an inherent flammability, which means an external flame is applied to it, the plastic will decompose, generate volatile gas, and finally ignite.

The flammability of all plastics can be divided into three general categories: highly flammable, flammable, and flame retarding. Some plastics light very easily and continue to burn very rapidly; these are considered to be highly flammable plastics. The most important of these are; polystyrene, acrylics, polyethylene, cellulose, polyethylene terphthalate (PETE), and polyurethane. Most of these are commonly used in packaging, home and office appliances. Polyurethane's are used in bedding, carpets, clothing, wall covering, and insulation. Plastics which are flammable are those that do not light or burn very easily. These plastics are the polycarbonate, silicones and polysulfones. The flame retarding plastics burn as long as an external flame is present. However, once the flame is removed, the plastics will self-extinguish. These plastics are the polyvinyl chloride, Teflon, nylons, polyesters, and any chlorinated plastic. The flame retarding properties of these plastics are the result of their ability to develop a crust or oxide layer over the plastic melt which inhibits volatile gas from escaping. Other plastics which are included in this category are the thermoset plastics which do not melt and when exposed to combustion their surface molecules rapidly decompose to produce a dense charring.

The inherent nature of plastics materials to burn easily gives added importance to testing their flammability. Presently there are eleven ASTM, several Underwriter Laboratory, private testing agencies, and government approve tests for assessing the flammability characteristics of plastics. These tests measure various flammability properties such as burn rate, extent of burning, flash and self-ignition temperature, oxygen index, smoke density, flame spread, ignition time, flame travel, and smoke percent and release rate. Insurance underwriter groups, manufacturing associations, plus trade and building code associations have established codes and flammability requirements for plastic products. Every area of manufacturing plastic products establishes specific requirements for smoke generation, toxic fume emission and burning temperatures codes.

The reason car manufacturers rely on plastics is it is cheaper.
Talk to a few automotive engineers to enlighten you on this subject matter also the underwriter labs cna help you out on those ratings as well.

Now for curb weight a 1973 Se charger with a LA 318 weighs in

The base engine in the Charger was the thoroughly lackluster 318-cubic-inch (5.2-liter) overhead valve V8. Inhaling through a two-barrel Carter carburetor, the 318 was rated at a nominal 230 gross horsepower â€” and likely made far less. Backed by a standard three-speed manual transmission or optional three-speed Torqueflite automatic, the 318 was severely challenged by the Charger's 3,500-pound curb weight.

Now the 1971-1972 satellite/roadrunner/gtx platform vehicle used less metal. Check the length, width, wheel base, history etc etc. So explain to me how a LA340 satellite/roadrunner/gtx weighs in
at a higher weight than the much larger Charger?

JosephGiannini · Post by **JosephGiannini** » Wed Mar 14, 2007 1:33 pm

And I want a steel grille for the fact plastics dehydrate and become brittle over time. Henceforth the discoloration in th white plastics as they become brittle. I do not like age warping in plastic or the brittle factors that come with it. Now granted you have no choice as far as the electronics go or some seals. Such as i cant manufacture new type of wire coating tha tis better than rubber/plastic composite wiring. But as far as body parts go. If I can do it I stay away from plastic parts. One for a safety reason. Two for a longevity reason.

JosephGiannini · Post by **JosephGiannini** » Wed Mar 14, 2007 1:43 pm

And as far as originality goes you are telling me I dotn have the ability to make a grille out of metal to look exactly like the plastic one?
You do know it is easier to manipulate metal than plastic right?
I mean for originality. Hmm lets see simulated wood or real wood?
Why did they paint the grilles with matt finish or simulated metal paints?
Cost saving. Come on now. Lets be honest. In the history of Chrysler
After 1971 detuned cars. Became all show no go. And you worry about weight all I have to use in thin metal or even aluminum not hard to do.
I mean you want originality. A what big block hemi that produces 425 AMA hp. All that weight up front you can get the same out of building a well made 318 with less weight. Why do you think nascar went away form bigblocks and stick with small blocks? You talk about nose weight but you pack a Gas Guzzling big block? Give me a break. Did you tube out your front end? Tube frame those control arms and that K member? One it is stronger. Two it is lighter? If i want to shed a lot of weight it is easy to do.

Post by **Eric** » Wed Mar 14, 2007 7:52 pm

All that to say that plastics are flammable...ok you're right, plastics burn and put off toxic fumes. If it were inside the car I might be worried, but there are a lot of other things on or in the car that also burn. Carpet for one thing, rubber burns pretty good too....

71 runner weight came from the special Road Test Magazine 1971 Car of the Year Award brochure...issued by CHRYSLER. Take it up with them if you don't believe me.

But again, you can build your car however you want. I have no desire to argue this....I'm done.

1bluegtx · Post by **1bluegtx** » Wed Mar 14, 2007 10:17 pm

JosephGiannini wrote:And as far as originality goes you are telling me I dotn have the ability to make a grille out of metal to look exactly like the plastic one?
You do know it is easier to manipulate metal than plastic right?
I mean for originality. Hmm lets see simulated wood or real wood?
Why did they paint the grilles with matt finish or simulated metal paints?
Cost saving. Come on now. Lets be honest. In the history of Chrysler
After 1971 detuned cars. Became all show no go. And you worry about weight all I have to use in thin metal or even aluminum not hard to do.
I mean you want originality. A what big block hemi that produces 425 AMA hp. All that weight up front you can get the same out of building a well made 318 with less weight. Why do you think nascar went away form bigblocks and stick with small blocks? You talk about nose weight but you pack a Gas Guzzling big block? Give me a break. Did you tube out your front end? Tube frame those control arms and that K member? One it is stronger. Two it is lighter? If i want to shed a lot of weight it is easy to do.

A 318 running with a hemi no way! i will take the hemi.As for nascar the hemi and the big fords were dominating nascar so they outlawed them and made the 355 cubic inch rule(who do you think that was for?)It had nothing to do with nose weight.

BRIAN

JosephGiannini · Post by **JosephGiannini** » Fri Mar 23, 2007 3:23 pm

you mean stock right hp for hp yes you can get a 318 to 425 hp no problem not a lot to do to it either now you talking baout building it up?

patrick · Post by **patrick** » Sat Apr 28, 2007 11:22 am

I am going to have to agree that the plastic grille was a cost-savings measure and the factory probably would have made it metal if they could justify it; however, I am also going to bet that, while metal would last more than the lifetime of the vehicle, the stock grille lasted a good 30+ years and is "good enough" and if so much effort's gonna be put into it, why not fix a thousand other factory cost-saving measures, and besides, if people are going to spend any real money on something, they're going to want it OEM correct and date stamped/numbers matching (I'm not one of those types, but know plenty who are). That being said, I will support anyone who is trying to preserve our old Mopes 100%, even if that means taking up a donation as long as it's an honest attempt.

Also, I know they make the complete '69 Road Runner grille, so who knows what will be available in time, but then if you reproduce the '71 year, it will cover that year plus the '72 Satellite only (the '72 RR grille is different).

Anyway, I have a '73 which is like way different, and on a separate issue, anyone know how to fix grille cracks? I have no missing chunks at all, thank God, just two cracks that go all the way through (but if I press the grille together, they kind of disappear).

72GY9Runner · Post by **72GY9Runner** » Mon Apr 30, 2007 11:24 am

Hi Patrick,

I repaired cracks like that on my 72 grille with good ol' JB Weld. I just separated the crack a bit, and forced the epoxy into it. Depending on the crack location, you can also smear a little over the back side of the crack to add strenght. I found that if you let is set for an hour or so, and then wet a finger tip. You can smooth out an overlapped piece like this so that it doesn't even show.

Once it had dried 24 hours, I sanded off the excess and repainted.