Expert: Ben Deutschman - 1/2/2010

Question
QUESTION:
I have a 1964 dart GT with a slant-6 225 with a carter 1 barrel carb, and an automatic tranny.

The car drove well enough for the short time after i bought it, but has been sitting for about 2 years since then, and I really want to get this extremely reliable for use as a daily driver. My question, is what procedures should I do to make this run like 'new' again? I've just swapped out the fuel filter, air filter, condenser and points so far. The plugs and wires look fine, and it will start, but only after lots and lots of pumping the throttle. Also, the previous owner told me the "accelerator pump" was going out when i bought it. I know that's in the carburetor, but could not find a rebuild kit for that carb.

Any help from an expert would be great, seems like everyone I usually turn to for engine and mechanical advice is only well-versed in Chevy, and some ford. Mopar seems to be lesser known.

Thanks!


ANSWER: A worn Accelerator Pump in the Carburetor, will have absolutely no effect upon starting, even dead cold. A misadjusted Choke, or non-functional Choke will affect cold starting, and that can be somewhat checked by simply making sure the Choke is open on a cold Engine, and then moving the Throttle just enough to allow the Choke to try to set (snap closed). If the Choke sets, then you need to check the Choke Pull-Off, which is near the Choke, on the Carburetor. With a hand Vacuum Pump, you need to draw a vacuum on the Choke Pull-Off, and see of the arm coming out of it moves, and as long as vacuum is applied, that the arm stays pulled in. If the Choke and Choke Pull-Off test okay, I'd get what we used to call a 'Jiffy Kit', and replace the Needle and Seat Assembly that threads into the front (or on Holley 1920 Carburetors), the passenger's side of the Carburetor. Of course use all the new matching gaskets, and since you're in there already, if the kit includes the Accelerator Plunger, replace that too. Also check the Carburetor Float in the 'Fuel Bowl' while you have the Carburetor apart, and if it's a brass Float, make sure it doesn't have any Fuel inside it. If it does, than the Solder Seam has been breached, and the Float won't rise when Fuel enters the 'Fuel Bowl.' A replacement 'Float' may be available through your local Auto Parts Store, or try http://www.rockautoparts.com. Make sure you carefully, and thoroughly clean ALL gasket mating surfaces before reassembling your Carburetor, including the bottom of the Carburetor 'Baseplate', and the mating surface on the Intake Manifold. Be VERY careful NOT to get ANY dirt particles in the Carburetor, or ports on the 'Baseplate' while cleaning the Gasket mating surfaces, and thoroughly spray (with Carburetor Cleaner) all parts before reassembly. Also, make sure the 'Float' in the 'Fuel Bowl' is set to the correct height, specs for that should be in with the 'Carburetor Kit.'

When installing your new Spark Plugs, DO NOT use the 'Crush Washers' that come on the Plugs. If you do, the Plug won't fully seat in the hole it threads into, and it will have the effect of using a colder heat range Spark Plug than your car should have. Carefully use a pair of cutting Pliers to remove the 'Crush Washers', then install your new Spark Plugs. If the previous owner had been using those 'Crush Washers', then you will need a 14 millimeter 'Thread Chaser' to clean out the threads, so the Spark Plug can seat properly. On Slant-Sixes from 1960-1974, the aluminum tubes the Spark Plugs fit in, act as the Spark Plug Gasket.

---------- FOLLOW-UP ----------

QUESTION: Thank you for all that information, it was very helpful!

What other tell-tale things might I pursue with this engine, that are common? I know the exhaust manifolds are prone to cracking (mine has a huge one already) so I am looking into how to repair a cast manifold, or places that offer steel tube headers.

I am a huge beginner in this area (mechanical stuff, in general) and just want to keep this car for a long long time.

Thanks in advance!

Answer
Other than making sure the Valves are adjusted correctly (.010 Intake,.020 Exhaust), I also suggest making sure when you replace, or reinstall the Intake/Exhaust Manifold assembly, that the three Bolts holding the two Manifolds to each other, are torqued to 15 foot pounds, no more, and don't tighten them until you have the Manifolds loosely hung on the Cylinder Head Studs, then tighten those three Bolts to spec first, then start the sequence of tightening the Manifold to Cylinder Head Bolts next (10 Foot Pounds). If you have, or can get, a good 'Shop Manual' for your car, that will have the correct tightening sequence for the Manifold to Cylinder Head Bolts. Oh, and generally, when the Exhaust Manifold cracks, it's due to improper torque of those three Intake to Exhaust Manifold Bolts.

Btw, the Valve adjustment is done using a flat 'Feeler Gauge', on a fully warmed up Engine, and you have to have a remote Starter Button to crank the Engine, so you can get each Tappet on the fully closed position of the Valve below it, before checking the 'Air Gap.' Too tight, and you'll damage the top of the 'Valve Stem', too loose, and the 'Tappets' will be very noisy, and again, you'll damage the top of the 'Valve Stem.'