Hi from Phoenix AZ! Picked up a non-running 1974 Plymouth Valiant Scamp

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DigitalRelay

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After a long day driving, renting a trailer, loading and unloading in the AZ summer heat, I've got a 1974 Plymouth Valiant Scamp /6 auto in my garage. The seller claimed he bought it from a salvage yard he worked at a few years ago with the intention of a Hemi engine swap, but it sat. He believes the engine was rebuilt around 2013, but never started up. It appears the engine was painted while disassembled, and there's a mostly empty full engine gasket set box in the car, so it seems plausible. I tried turning the engine by had with the fan, but it is currently stuck. I plan to pull the plugs, spray some penetrant in there, pull the starter, and see if I can slowly get it to move. I'm also going to see if I can get my hands on a borescope and take a look inside the cylinders. The VIN says it came with a 198, but the stamp on the block says 3W225. I could not find a vin stamp on the rear of the block. It is a factory AC car, which I eventually would love to convert to R134a and get it working. I was surprised to see it's got 4-wheel drum brakes. I figured by 1974, front discs would have been standard. I guess not. Front disc brake conversion is almost assured if/when I get this running and driving.

I'm in my mid 50s and have been wrenching on cars since I was a teenager. I've owned a '67 Mustang, '69 GTO, '73 Monte Carlo, '69 Skylark in the past. I've pulled engines, transmissions, did a disc brake conversion on the Skylark and in general have some experience. I'm hoping I don't need to pull the engine on this, but if it comes to that, oh well.

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Nice score, and welcome.

The factory AC is a nice plus and almost mandatory in Phoenix. The 134A conversion is pretty straight forward.
 
Welcome! Awesome to see another late year Scamp being saved and put back on the road eventually!

Front discs were not standard until January 1976 so it was only the late 1976 model year A bodies that had them all.

I suspect your Scamp was made late in the production run for the 1974 model year since your front and rear bumper guards are from 1975. Or the previous owner swapped them but that would be unusual since most of the time the modification is to remove them entirely. The 1974 bumper guards had larger black plastic blocks sticking out from the chrome guards.

You’ve got the 1974 front grille. Does your instrument panel have one or two idiot lights to the left of the speedo?

Watch out for the dreaded seat belt interlock that was only on 1974 models (and some very early 1975 models) as it causes problems (which is why it was only used for one year).
 
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Thanks, everyone! Good news!! I pulled the plugs, sprayed a little WD40 in there, pulled the starter and slooooowly turned the engine with a large screwdriver. It is free! I also stuck a borescope in each cylinder. Only one has a little surface rust. I also noticed the pistons are all stamped 30, which I'm assuming means the engine was rebuilt, bored .030" and got new pistons. I think I'll get some oil in the cylinders and slowly turn it over a few more times before I move onto getting a battery.
 
You can do it ,,,,,I’m certain you can get it running and driving .
It looks like it has a brand new radiator,,,,among other things .
Pull the plugs and put some Marvel in there,,,,,it should break loose fairly easy .
That will be a nice ride when you get through .

Tommy
 
It's alive!! After fixing a couple of very sketchy existing wiring repairs, I threw a battery in and poured a little 50:1 2-cycle fuel down the carb and got it to run for a few seconds. I'm stoked!

Unfortunately, the gas tank is filled will who-knows-how-old gas in it that looked and smelled terrible. The carb also started to overflow. I'll grab the rebuild kit tomorrow and hopefully work with my local fire department to get rid of the 8-10 gallons of old gas in the tank. The tank actually looks brand new though.
 
Nice Scamp, sir! It looks like you have the HEI upgrade, that's a good one. Also, a 75 is (I'm all but certain) going to be a lean burn engine. There are a herd of vacuum lines, gizmos, and wiring that go with that business. I trashed all that stuff on my truck since it's not required here, but you may want to investigate that deal. If out of whack it makes the engine run poorly.

If you need a new gas tank Spectra makes good ones that are affordable. If you swap it out make sure you keep the sender retaining ring off your factory tank and re-use it. The one that comes with a new tank is junk.

Keep the info and photos coming!
 
halfafish said:
Nice Scamp, sir! It looks like you have the HEI upgrade, that's a good one. Also, a 75 is (I'm all but certain) going to be a lean burn engine. There are a herd of vacuum lines, gizmos, and wiring that go with that business. I trashed all that stuff on my truck since it's not required here, but you may want to investigate that deal. If out of whack it makes the engine run poorly.
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You’re probably thinking of the air pump that was put on some engines in 1975. Chrysler’s lean burn system was introduced until 1976 and only then on the 400. In 1977 Chrysler installed it on all V8 engines.
 
H22A4 said:
You’re probably thinking of the air pump that was put on some engines in 1975. Chrysler’s lean burn system was introduced until 1976 and only then on the 400. In 1977 Chrysler installed it on all V8 engines.
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Thanks for the update. I was thinking lean burn started in 74.
 
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