Author Topic: 1970 Challenger RT/SE  (Read 5051 times)

Offline Padawan

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1970 Challenger RT/SE
« on: November 22, 2011 - 12:05:37 AM »
Today was the day, my Challenger arrived in Boston after departing from Texas 5 days earlier :bananasmi. After a rough start it turned out to hold up as the seller described and I'm very happy about that. The car runs and drives, though has a few rough edges and a lot of potential for improvements. I'll have to get it inspected this week, which I think it will pass, but we'll see that. :)

I am no mechanic and this is my first mopar, so the first thing that left me wondering is a loose pin in the carburetor. I just know how a carburetor is supposed to work, but what is this Z-shaped pin in the lower left quarter of the first image supposed to do? Also the arm just above it, controlling the throttle plate, it looks like there should be a cable going through there, but there is nothing there. As described in my welcome-noob-thread, the car would not start unless the throttle plate is fully opened manually (and it stays that way), even a cold start now works fine from that position.

Would be great if somebody could explain to me what is going on here. Happy to supply additional pictures! (though I'll be away the next two days)
1970 Challenger RT/SE 383

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Offline Jamiez

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Re: 1970 Challenger RT/SE
« Reply #1 on: November 22, 2011 - 06:28:39 AM »
From your other thread:

The clocks on these cars were electromechanical, which means that they were little more than a spring and a motor to wind it.  They were sealed units from the factory and were just not designed to last 40 years.

There is a company that makes a replacement that uses a standard quartz movement.  It takes a lot less power, is more accurate and should last a very long time.  They offer a do-it yourself kit or have a service where you can send them the unit and they swap the internals.

The gas gauge can be a number of things, from the gauge to the sending unit in the tank.  If you search you should find a number of threads for troubleshooting the problem. 

Offline Bullitt-

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Re: 1970 Challenger RT/SE
« Reply #2 on: November 22, 2011 - 06:59:23 AM »
The item you describe as a throttle plate is the choke, the Z-shaped piece is part of the choke spring, a thermal spring that opens & closes the choke. It appears the missing cable is for a manual choke that would run to the interior of the car. There should be a way to convert that carb to the automatic choke but not being a Holley guy I can't say what that is.
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Offline Jamiez

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Re: 1970 Challenger RT/SE
« Reply #3 on: November 22, 2011 - 07:15:07 AM »
Holley typically sells kits to convert from one type of choke to the other.  You would just need to know the model of the carb.  It should be stamped/cast somewhere on the carb. 

Alternatively if you only plan on doing summer/warm weather driving you can go without a choke.


Offline Padawan

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Re: 1970 Challenger RT/SE
« Reply #5 on: November 23, 2011 - 11:54:07 PM »
The clocks on these cars were electromechanical, which means that they were little more than a spring and a motor to wind it.  They were sealed units from the factory and were just not designed to last 40 years.

There is a company that makes a replacement that uses a standard quartz movement.  It takes a lot less power, is more accurate and should last a very long time.  They offer a do-it yourself kit or have a service where you can send them the unit and they swap the internals.
That sounds great, what's the company that makes them called? I found some offerings for complete clock replacements only.

The gas gauge can be a number of things, from the gauge to the sending unit in the tank.  If you search you should find a number of threads for troubleshooting the problem.
The gas gauge goes to zero when the car is shut off and goes all the way up and beyond "F" when started. I'll see what I can find about that with a search, thanks!

The item you describe as a throttle plate is the choke, the Z-shaped piece is part of the choke spring, a thermal spring that opens & closes the choke. It appears the missing cable is for a manual choke that would run to the interior of the car. There should be a way to convert that carb to the automatic choke but not being a Holley guy I can't say what that is.
I should have pulled up that German-English dictionary first -- if that was the throttle plate I'd be driving like mad. :D The Z-thing feels a little loose, but I'll hook it up to the choke so it stays open for now. I'll probably just get one of the electric chokes @ragtopchally suggests, but the engine starts so well with open choke I'm in no rush for that. The choke block-off replaces the part where the Z-shaped thing protrudes from, right? Should I get one of these anyway?

Thanks for all the input, great help!
1970 Challenger RT/SE 383

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Offline Jamiez

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Re: 1970 Challenger RT/SE
« Reply #6 on: November 24, 2011 - 12:54:51 AM »
That sounds great, what's the company that makes them called? I found some offerings for complete clock replacements only.



Here is a link to the clock repair kit/install service.  I never used it myself as I was able to pick up a NOS clock for around what they were looking for.
http://rt-eng.com/mediawiki/index.php/Dash-Worx_E_Body_Clock_kit

The gas gauge goes to zero when the car is shut off and goes all the way up and beyond "F" when started. I'll see what I can find about that with a search, thanks!


The gas gauge normally goes to 0 when the car is off. Obviously it shouldn't read full unless the tank is full.  :) 

Offline torredcuda

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Re: 1970 Challenger RT/SE
« Reply #7 on: November 24, 2011 - 07:16:48 AM »
The sending unit needs to be grounded to the body and sometimes that is missing.Check where the fuel lines come out of the tank and there should be a metalbraided strap for a ground(or ust a piece of wire as a replacement).Also a separate issue I noticed under the hood on your firewall the ballast resistor(white rectangular piece) is not connected up-not sure why as it is part of the engine electrical system.  :clueless: If you don`t yet have one get a service manual which will give you al the wiring diagrams.They are available in book form or CD.
Jeff
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Offline Bullitt-

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Re: 1970 Challenger RT/SE
« Reply #8 on: November 24, 2011 - 09:03:58 AM »
That sounds great, what's the company that makes them called? I found some offerings for complete clock replacements only.
The gas gauge goes to zero when the car is shut off and goes all the way up and beyond "F" when started. I'll see what I can find about that with a search, thanks!
I should have pulled up that German-English dictionary first -- if that was the throttle plate I'd be driving like mad. :D The Z-thing feels a little loose, but I'll hook it up to the choke so it stays open for now. I'll probably just get one of the electric chokes @ragtopchally suggests, but the engine starts so well with open choke I'm in no rush for that. The choke block-off replaces the part where the Z-shaped thing protrudes from, right? Should I get one of these anyway?

Thanks for all the input, great help!


one company offering clock internals http://rt-eng.com/mediawiki/index.php/Dash-Worx_E_Body_Parts

I'm guessing the gas gauge going to F is not a ground issue. Do the other gauges perform correctly? If so I would be looking at the sending unit in the tank.  A bad voltage limiter (stuck closed)  could cause all the gauges to read to high but not just one. New solid state voltage limiters available http://rt-eng.com/mediawiki/index.php/Image:ELimiter.jpg

as for connecting the Z-shaped choke spring to that carburetor Don't, the hardware is wrong.  The electric choke would be the easy solution. Yes the choke block off replaces the Z-shaped choke spring for cosmetic purposes. 
Wade  73 Rallye 340..'77 Millennium Falcon...13 R/T Classic   Huntsville, AL
Screwed by Photobucket!

Offline Padawan

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Re: 1970 Challenger RT/SE
« Reply #9 on: December 15, 2011 - 10:42:25 AM »
Not much progress here, I hope to get more done after x-mas.

The sending unit needs to be grounded to the body and sometimes that is missing.Check where the fuel lines come out of the tank and there should be a metalbraided strap for a ground(or ust a piece of wire as a replacement).

I'll crawl under there and check next time I get a chance, thanks!

Also a separate issue I noticed under the hood on your firewall the ballast resistor(white rectangular piece) is not connected up-not sure why as it is part of the engine electrical system.  :clueless: If you don`t yet have one get a service manual which will give you al the wiring diagrams.They are available in book form or CD.

I now have one; there is a lot of incomplete and custom wiring in my car, I need to document all that at one point and then get to fix it. :thumbsup:

one company offering clock internals http://rt-eng.com/mediawiki/index.php/Dash-Worx_E_Body_Parts

I'll postpone the clock restoration to when I restore the radio, do all the expensive small stuff at once. :D

I'm guessing the gas gauge going to F is not a ground issue. Do the other gauges perform correctly? If so I would be looking at the sending unit in the tank.  A bad voltage limiter (stuck closed)  could cause all the gauges to read to high but not just one. New solid state voltage limiters available http://rt-eng.com/mediawiki/index.php/Image:ELimiter.jpg

Yes, the other gauges mostly seem to work (except for RPM); at least they don't stay at either end. I'll have a look at the sending unit first!

as for connecting the Z-shaped choke spring to that carburetor Don't, the hardware is wrong.  The electric choke would be the easy solution. Yes the choke block off replaces the Z-shaped choke spring for cosmetic purposes.

I wanted to put in the choke block off only to find that the exact thing was already installed, below that Z-shaped spring. So the Z-thing is now gone; anybody needs a choke block off? :roflsmiley:

Thanks for all the help so far!!
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Offline Padawan

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Re: 1970 Challenger RT/SE
« Reply #10 on: January 20, 2012 - 09:49:43 PM »
According to the garage floor, my Challenger was loosing more oil than Kuwait is exporting in a full year, so I had to find a garage and brought it there. It's currently on the lift and the reason was that the oil-pan was dented, but no bad damage so this is an easy fix. While it's there I'll have the tranny redone, the engine seemingly has been redone recently (I've only had the car for 2.5 months now) and is still very clean, you can imagine how glad I was to hear that.

They said the fuel gauge is already fixed, was an electrical problem they mentioned they had found, will have to ask what exactly that was.

Also, they showed me some plugged holes in the sheet metal that they said someone used to undercoat the car, does someone have more information about how that works? Luckily the metal is still in very good condition all around. :clapping:

Forgive my noob "restoration" project, I know the stuff here is ridiculous when compared to all the other projects of you guys. :worshippy
1970 Challenger RT/SE 383

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Offline hemiken

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Re: 1970 Challenger RT/SE
« Reply #11 on: January 21, 2012 - 12:09:44 AM »
What they were trying to tell you about the holes is that someone injected a rust inhibitor or fish oil to prevent rust forming in areas that collect dust and water to form rust in your rocker panels and such, very good score finding someone who cared enough to fill it with love to conserve it for the next generation :jumping: :clapping: :2thumbs:
1970 Barracuda   (O^--^===|===^--^O)
1971 Barracuda   (O O {]{]{]|[}[}[} O O)
1970 Challenger  (O O [======R/T=] O O)
1971 Challenger  (O O ===== ===== O O)
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