"Testing a 6-Volt Electrical System"
For all of you who have followed our '54Coupe DeVille cooling problem saga, here's an update: We've had some high 80-degree days, and the car with the a/c on runs cool (185-190). We do have some further information about increasing water flow at an idle. If a high flow impeller is not available, changing to a smaller water pump pulley causes the water pump to pump more water, but does not affect the power steering, a/c compressor, or other engine accessories. ) If a larger crankshaft pulley were used, however, it would speed up everything on the fan belt, resulting in excess wear). Our pulley is a double belt 7", and we're stepping down to a 6". We'll let you know next summer on a 100-degree day what results we get!
On to our other projects... After the excellent results we had after changing to heavier battery cables (0/1), and grounding the engine block to the frame on our '46 Chevy Panel Truck, we are doing this on all of the cars. We bought 0/1 welding wire cable (welding cable has smaller and more wires, giving better current flow), and copper 0/2 cable ends. The larger ends leave room for he solder to fill before inserting the cable. We cut the cable length, and then stripped the insulation back on each end to about 3/4". A vise held the copper cable end while it was heated with a propane torch and solder melted in. While the solder was "hot", the cable was inserted. To finish off the joint, slip a 1" piece of 5/8" heater hose over it for a neat appearance. We are also installing cable disconnect switches. There are several types available, and we used different ones depending on the battery placement in each car. (Several vendors in this issue have these available). One type connects to the negative battery cable at the battery post and disconnects by unscrewing a plastic wheel, separating the cable from the end. The second type breaks the ground cable and is turned on and off with a switch. Both types work well and are good for long storage or as an anti-theft device.
After we had put on the new cables and grounded the block to the frame on our '41 Packard 180 LeBaron, we still had starter drag. Even though the car is being disassembled for restoration, the engine will only require minor refurbishing and we are temporarily keeping it running to move the car in and out of the shop. The engine is the original 356, 9-main-bearing straight 8. To check our starting problem out, we put in a good hot battery and checked all of our connections. Still, the old straight 8 turned over slowly. We pulled the starter to test it, using our Matco amp gauge.
We "no-load" tested it using 4-gauge test wire. It tested at 100+ amps (77 is correct). Our volt meter showed 2.5 volts (below 4 volts indicates a problem). Since the car had been sitting, the obvious place to check was to solenoid for sticking points, corrosion or wire damage. Restorer Charles Butts disassembled, cleaned and reset the points and got the contact plunger to work after years of sitting. Again, we "no-load" tested it with 4 gauge (12 volt type) test leads. Now, the amps were a correct 77 and volts a correct 5.5. Next we did a comparison test using our new 0/1 cables on a "no-load" test. The amps dropped to 55, clearly showing the advantage of using heavier cables (less amp draw). Our amp gauge only goes to 600, fine for no-load tests and most 12 volt systems, but not enough for 6 volt "load" tests, where a 1000 amp tester is needed. The "load" test (on the car or under tension) on our '41 is 906 amps! These 1000 amp gauges are hard to find and can be pricey! We found one that hooks to a volt meter for under $50 at Sears. It's on order, and we will let you know how it works next month.
With the car now starting, we checked our timing. It was 15 degrees BTDC instead of 8 degrees, called for by the original specs. When we reset it to 8 degrees, it wouldn't start. Having to set timing at other than original specifications could indicate a worn timing chain or distributor. These will be checked out later. For now, we re-set it to 15 degrees. To test the rest of the system, we removed the spark plugs (ACM-8s), cleaned, set and re-installed them. We used our new Matco Smart Tach to check voltage at the plugs. Do this by extending the antenna and hooking the end around a plug. Push the "peak" button (be sure to wear heavy rubber gloves!), and you will get a digital reading in thousandths. A minimum 20,000 volts per cylinder was what we were looking for, and all 8 had 21,000+ except #5and #6. They read "0", indicating bad plugs or bad wires. We removed #5 and #6 wires. They tested good so the plugs were bad. These were replaced, and now all 8 reach 21,000+ volts. The car now will run and drive in and out of the shop. Our body work will be the main focus over the winter months, having already stripped the car down to the body. Next month, we'll be welding and doing panel fabrication. Have a great month and keep 'em driving!