Restoration Clinic: Mopar battery cables
Many new questions and responses have come about as a result of my ’69½ display engine at the Carlisle show this past July. First off were inquiries about the correct positive battery cable; the 1969 model year introduced a new positive battery cable, which is part number 2926754 for the 383 and 440 4-bbl B-body cars. I know, however, that the parts book for ’69 and ’70 calls for part number 2926085 for this same application. As we have discussed before in this column, over-the-counter parts and assembly line parts would often differ, so this is another example of an engineering change made for the assembly line part, while leaving the original part number (which debuted during the 1968 model year) in all the parts books.
The article featured on this page is from the January 2010 issue of Mopar Enthusiast Magazine.Click here to read the free digital edition of Mopar Enthusiast now.
The “085” cable introduced in ’68 had the part number printed in white ink along the length of the larger red cable; no paper tag for the part number was used. Also, the connection at the starter incorporated two separate wires with a unique shrouded lug end for the primary (thicker) red wire. For the 1969 model year, the assembly line “754” replacement cable had a new siamesed starter lug connection, and the new part number was printed on a baby blue tag and wrapped around the black tape and wires about three inches or so from the starter connection. (See detail photo.) There was no separate 440-6 positive cable beyond this, and this 2926754 cable was also used throughout the 1970 model year in 383/440/440-6 B-body cars. Meanwhile, 2926085 continued as the over-the-counter number found in the parts book during this time.
Next, let’s verify the fuel pump applications. The ’69½ cars used a Carter 4434S, Chrysler part number 3004107. This was in fact the same 1968/1969 440-4bbl high-performance (B-body) fuel pump used in conjunction with the vapor separator system. This is an extremely hard to find pump today, and originals are very rare. However if you can find one by the original part number, chances are it will be a good dated 4434S pump for the 1969½ application. Also, ALL ’69½ cars used 5/16-inch fuel supply lines.
Next were many inquiries about the engine harness. The engine harness part number for the 383-4bbl and 440-4bbl was 2926391; a modified version of this same “391” harness was used on ALL ’69½ cars. It was modified for two reasons: 1) The coil mounting was relocated for the 440-6 engine; 2) a carb/idle solenoid was added.
The 383/440 coil was mounted at the front of the intake, and the standard 4-bbl harness had a dark blue wire connection for this, about five inches long. However, this wire would not reach the new mounting position for the 440-6 coil, and a quick, cheap fix was engineered. First, the original coil wire was crudely snipped off and that open wire was merely taped around with cloth friction tape to disable and insulate it. Then a unique “piggyback” type terminal lug was used to connect the new, much longer (29-inch) blue coil wire at the ballast resistor and then completed the circuit to the coil connection.
The special solenoid wire, approximately 54 inches long, also utilized the same piggyback lug end at the ignition terminal of the voltage regulator. This allowed the solenoid to be activated or released with the ignition switch. The solenoid wire was spot taped along with the standard wiring routed along the right valve cover. The wire was then routed around the front of the intake to its connection at the solenoid on the opposite (drivers) side. There was a special nylon plastic clip affixed to the inside of the left valve cover which held this wire in place, with both of these added wires spot-taped to the original harness. Various locations of the spot tape and routing of the wires have been seen on original cars. However, the solenoid wire was consistently found to be routed around the front of the intake.
What about the numbers on the front of the valve covers? Personally, I have always thought this was a very redundant type of engineering/assembly process and have wondered about the reasoning for this procedure for some time. Here’s why. The front of the left (driver side) valve cover often had a “5” or “0” which denoted either an automatic or four-speed transmission engine, respectively; these numbers were applied by hand. The front of the right (passenger) cover often had a 3-digit number corresponding to the engineering number assigned for the engine assembly, in this case a 440-6 automatic engine or a 440-6 four speed engine.
As a rule, for assembly-line-built, standard-engine-equipped vehicles, the proper engine assembly number is found on the build sheet. Well, we all now know these were specially-built cars and were first built as standard 383 Road Runners or Super Bees. So Lynch Road noted these engine assemblies on the fender tag as well as the build sheet during that part of production. Now here is the rub. Automatic 383’s were “926” engine assemblies and 383” four-speeds were “925” engine assemblies and these numbers (925 or 926) appear on ALL ’69½ FENDER TAGS. However, these are NOT the engine assembly numbers for the special 440-6bbl automatic or four speed engines! Therefore, the 383-codes of “925” or “926” should not be written on the front of the right valve cover. Those numbers were most likely applied during the engine’s original assembly, not during the vehicle’s actual production – so they would not have been used on any 440-6bbl powerplant since they actually denoted the 383 engine. Admittedly, very few original surviving examples of untouched ’69½ cars exist, but I have seen a few. The engine assembly numbers for a ’69½ 440-6 automatic is “950” and that is the correct number which should appear on the right valve cover. And I am assuming the correct number for a 4-speed is “949,” though I have not seen an original 949 marking as yet.
In an upcoming issue, we will take a more-illustrated, in-depth look at these unique engines, as their popularity has made them prime candidates for restorations, and restoration errors. See you next month.n
Note: Frank Badalson is an acknowledged authority in the Mopar restoration field. You can send him your questions at: Restoration Clinic, Mopar Enthusiast magazine, P.O. Box 482, Sidney, Ohio 45365-0482, or e-mail him at MoEeditor@amosautomotive.com.
Tuesday, July 13, 2010
Tuneups and Diagnostics
Unless you are one of those “hermetically sealed, never driven” musclecar collector types who has forgotten what musclecars were all about, you enjoy driving your car.
The article featured on this page is from the February 2010 issue of Musclecar Enthusiast Magazine.Click here to read the free digital edition of Musclecar Enthusiast now.
Whether it is a long road trip or just the occasional weekend trip for dinner and a movie, your musclecar needs to run right. In the modern age of computerized engines and fancy tools, real-world, old school tuning has been lost. Unless you remember all the ins and outs of tuning and diagnostics, you may need a bit of a primer. While one page is way too short to get into much detail, I have a few tips and tricks, and a really neat tool that will make tuning much easier.
Engine not running smoothly or not firing at all? Before you get flustered, pick up the Spark Plug Sensor from OK Spark. This handheld sensor not only tells you if you have a spark, but also will tell you if the plug is firing. No more shocks (we have all been zapped by the coil using a screwdriver in the plug wire), no pulling plugs, no guesswork. The tool works with engine running or just cranking. It is a no-touch system, too — you just place the sensor near the plug and it takes a reading. The tool has a “real-time” setting for watching the readings, and a “snapshot” setting so you can attach the clip to a wire, crank the engine and then look at the results, which is great if you are by yourself.
If you are getting voltage to the plugs, but no spark, then your problem lies in the plugs. Chances are you have a few plugs that are fouled or worn, and this tool helps you find the ones that are not working so you can inspect and replace them, saving you a lot of time and headache.
If you are not getting voltage, then the problem lies in the plug wires or the distributor. The OK Spark works at the distributor cap, too, so you can see if you have voltage there. If not, then you have an internal issue.
The first thing to check is the cap and rotor. Pull the cap, and look at the contacts on the cap and the terminals on the rotor. If they are worn, it will be fairly obvious, as there will be a lot of carbon deposits and the terminal contacts will be uneven and show a lot of wear. You can always take them down to the local parts store and compare them to new parts if you are unsure.
The next spot of trouble, and one that will really throw a lot of enthusiasts, are the points. Points-style ignitions are reliable, but they do need adjustment and replacement from time to time. Since most musclecars have points-style distributors, let’s review a trick for setting the points.
First, you need to see if the points are burned. Burned points will have an obvious burn mark, accompanied by some pitting on the contact pads. Replacing the points and condenser is fairly easy and in most cases, there is no need to remove the distributor. Setting the points is not hard, but what if you are on the side of the road? In a pinch there is a trick to getting the points back in line. If you don’t have a spare set of points in your travel tool box, keep a piece of 500-grit sandpaper. Use the sandpaper to lightly file down the points, removing the carbon and softening the pitting. This will usually get the points to fire again. Now you need to adjust the gap. A business card or matchbook will get you to the approximate .019-inch gap needed for most points systems. Put it back together, and you have a spark.
How To Repair the Wiper Doors on your 1968-1972 Corvette
Vacuum-Operated Wiper Door Woes
Story and Photos by Chris and Stephanie Petris
One thing is for sure, the 1968-1972 Corvettes had cutting-edge technology. A vacuum-mechanical headlamp and wiper door with fiber-optic bulb status was undoubtedly innovative. It was quite an accomplishment to get the wiper door to close and open in conjunction with the wiper arms swinging around.
Certainly, fail-safe switches were incorporated to prevent inadvertent closing of the wiper door on the wiper arms. With the smooth transition from hood to windshield, the wiper door makes the 1968-1972 Corvettes unique in appearance and function.
The article featured on this page is from the May 2010 issue of Corvette Enthusiast Magazine.Click here to read the free digital edition of Corvette Enthusiast now.
Like our headlamp door res-toration story, the 1969’s wiper door was corroded and stuck in the closed position. The wiper door was stuck so badly that we removed the entire assembly to avoid breaking components. All of the wiper door linkage pivot points are plastic-bushed, and the corrosion made the bushings stick. Once you get the door linkage pieces out, you will realize that it took a lot of thought to make all these strange-looking linkage pieces to make the door move so smoothly. Our linkage was in decent shape except for the corroded pins and bushings. The pivot pins are actually job-specific rivets that require setting with a press or hammer to stake the pin in tightly. Another problem that we always encounter, no matter how well-maintained the ’68-’72 Corvette, is stuck wiper door to linkage screw-in pivot pin bolts. Wiper door screw-in pivot pin bolts corrode and then break as you try to remove them. We find at least one tight screw per wiper door, and this ’69 was no exception. All of the screws were tight and ready to break off. Every once in a while something goes right – in our case, discovering that tapping on the backside of the pivot screws to loosen them actually works. The idea is to tap on the backside of the screw to loosen the corrosion and allow the screw to release the threads.
Once all the pieces are apart, we can start the clean-up process and prep for paint. Before any final painting occurs, we will assemble the linkage and stake the pins in place. This avoids chipping and scratching the paint. After staking the pivot pins, we will paint all the linkage pieces with good-quality black epoxy paint. We have easier access before the linkage components are re-installed, so let’s move on to the vacuum system and installing the wiper arm switch and hoses.
A Systems Approach: The ’68-’72 wiper door vacuum system uses the same relay valve as the headlamp vacuum system with specific switches and two different style wiper door actuators. All 1968 and early 1969 wiper door actuators use a fiber piston seal that rides in the canister bore. Late 1969 wiper door actuators resemble a headlamp actuator with a captured rubber diaphragm in the center and an actuator shaft seal. The later wiper door actuator is very reliable, and if necessary, the actuator rod seal is replaceable. Due to their design, all early actuators have vacuum leakage by the fiber seal – some more, some less. For instance, you can close off the back side of the later actuator vacuum connection, preventing any actuator rod movement, while the early actuator will let you move the actuator rod as the vacuum bypasses the fiber seal. The wiper door control system is more complicated than the headlamp system due to wiper door and wiper mechanism movement. 1968-1971 Corvettes control the wiper door vacuum solenoid through a relay, which was dropped for the 1972 model year. The ’68-’71 wiper relay was placed in the console area and is controlled by the wiper switch. The 1969-1972 Corvettes use the same vacuum control solenoid as the 1968-1971 without the relay. The vacuum solenoid is a simple device that opens, allowing vacuum to dump when 12-volt power is applied. The solenoids are reliable – we see more damage from connector removal than solenoid failure. The connector must be carefully removed with side-to-side movement, or the terminal can be pulled out of the solenoid. 1969-1972 Corvettes use a vacuum switch on the wiper arm to prevent door closing until the wiper arm is fully parked. All of the wiper door systems use an override switch under the dash to bypass the relay (1968) and solenoid. The vacuum solenoid receives a signal from the wiper switch to route vacuum to the vacuum relay valve. Like the headlamp system, the relay valve sends vacuum to the wiper door actuator. All ’68-’72s have an additional override vacuum switch under the dash to open the wiper door.
Problem Areas: Like the headlights, vacuum leaks are the major concern, with a few switches that come into play. The 1969-72 wiper arm switch is prone to failure from the harsh environment (sunlight, water, etc.). All of the headlamp and wiper door vacuum systems use a vacuum reservoir to supply ample vacuum for quick wiper door operation. The same driver-side rear inner fender reservoir is used for the wiper door and headlamp system. The common problems are wiper arm vacuum switch, relay valves, and poor hose connections. The easiest way to troubleshoot the myriad of vacuum components is with a good vacuum gauge and pair of needle-nose pliers. Caps and plugs help isolate one system from the others, which in many cases, must be done because you may have multiple leaks. You can have all the relay valves leaking for both the headlamps and wiper door, for example. If you have access to a vacuum pump (an A/C vacuum pump works well), you can troubleshoot the system without the engine running to listen for audible leaks in the systems. If you are using the engine or an external vacuum source, you first need a baseline vacuum reading. This can be done by removing the vacuum source rubber hose and connecting the vacuum gauge to the engine if you are using engine vacuum. If you are using an external vacuum source, connect your gauge directly to the pump for the baseline reading. The next step is to tee the vacuum gauge into the vacuum system close to the source to begin leak checking. Then move outward on the vacuum source hose, clamping it with the needle-nose pliers until you see a rise in vacuum. If you are working with a ’68-’72 car, start by eliminating the headlamp vacuum system by plugging the supply line at the headlamp relay valve. If the vacuum reading rises, you know you have a leak at the front in the headlamp area. If the vacuum reading stays the same, plug off the wiper door vacuum supply hose and see if that makes the vacuum rise. You should be within an inch or two of the first vacuum reading when all the ports were blocked. What we need to know: Is the vacuum leak from a leaking relay valve or actuator? Since relay valves are prone to leaking, we can easily test them by plugging the green and red outlet ports. A good relay valve will have the vacuum rise close to the baseline vacuum. If it is down more than two to three inches of vacuum, the relay is bad. To save multiple part orders, you can use a vacuum splice connector to bypass the relay valve connecting the red vacuum actuator hose to the yellow supply hose to check for a vacuum loss. If you find a leak, the actuator diaphragm or the canister has a perforation. Actuator replacement is the only answer at this point. This same test can be done with the green actuator hose and the yellow supply hose. The green actuator hose is the push side that opens the headlamp or wiper door. Finding a leak on the green side of the actuator usually means the replaceable actuator rod seal is leaking. If there are no significant vacuum leaks and the headlamp doors do not work, you can apply vacuum to the relay valve’s small vacuum control port to see if the headlamps operate. You should find vacuum at the small hose when the headlamps are on. If no vacuum is found, look inside the car for the problem. If you found vacuum at the small hose, the relay valve is the problem. That is, of course, if the headlamp doors are not mechanically binding.
Do not be surprised if you find both of the systems leaking. Careful troubleshooting and repairs will get rid of the leaks, and you will even enjoy better engine performance. You will not be able to adjust the carburetor(s) to compensate for headlamp and/or wiper door vacuum for leaks that occur at the intake manifold. You can try to compensate for the vacuum leaks by adjusting the carburetor idle screws richer; but remember, the vacuum loss is after the carburetor so poor performance will result.
Inside Challenges: The cockpit vacuum system also has a myriad of hoses to contend with, but the difference is that they do not affect engine performance. Cockpit vacuum leaks are usually minor but significant because they operate at low volume, so any loss of vacuum can affect proper operation of the headlamps or wiper door. The headlamp control is simple; vacuum is supplied to the headlamp switch, and the headlamp switch routes vacuum to the headlamp door relay valve. The wiper door control is more involved and utilizes an electric vacuum dump solenoid that the wiper switch electrically controls. Both the headlamp and wiper door controls have an override switch to manually dump vacuum for wiper blade or headlamp replacement.
Cockpit vacuum problems usually occur after dash repairs have been performed because a vacuum hose is knocked off or broken. Original vacuum hoses usually fit loosely because of age, making them easy to knock off. The hoses themselves are not subjected to the under-hood heat so they stay in good condition for quite a while. Once all the hoses and components are installed, adjustments come next. Remember that the wiper arm vacuum switch must be fully depressed to allow the wiper door to close; likewise, the wiper motor armature switch must be depressed fully to allow the wiper motor to run.
Like our headlamp vacuum system, the wiper door vacuum system was in total disrepair, requiring us to replace all the vacuum system components including the relay valve, wiper arm switch, and all of the hoses. The vacuum hose kit system came with clear instructions on what length hose and indicates what color stripe goes where. Look at the supplied instructions and vacuum hose diagram carefully to assure that the correct length/color stripe hoses are used. It is easy to grab the wrong hose and think that something is wrong with the length. Take a tape measure and measure the hoses first – no cutting is required!
The Bottom Line: This is certainly a big step in driving the 1969 Corvette on long road trips. It is very nice to know that the headlamps operate without our under-the-car manual intervention. Having wipers that come on when you request them takes some apprehension away when we drive the ’69. One thing is certain – we will take the ’69 Roadster on longer road trips in 2010. Who knows? Maybe it is time the Corvette makes the trip to Corvettes at Carlisle.