| mike39 | -- 08-06-2013 @ 4:50 PM |
|
Hi all, Im working with a 40 coupe. Stock and 6 volt. Starts fine cold but after its warmed up it wont crank fast enough to start. Have to use a jumper box. New Interstate 750 amp battery. New repro cables and solenoid. New DB starter. All connections are good as far as I know. Ideas ? Don't want to go 12 volt. Thanks, Mike
|
|
| ford38v8 | -- 08-06-2013 @ 8:19 PM |
|
Mike, No need to go to 12 volt, so first off, check to see that your "new" cables are not 12 volt cables. 6 volt systems require 1/0 or 2/0 cables, including the ground straps. Put your hand on the insulated cable running from solenoid to starter. It shouldn't be warmer than the firewall itself. Correct gage cables with good solid clean connections are needed. The starter (What is a DB starter?) must be properly grounded also. Hot starts can be a problem from both electrical and fuel reasons. Modern fuel has a very low boiling point, and will evaporate out of a carb bowl during a lunch stop. You might also check the power valve, especially if the engine has backfired through the carb recently, which blows out the delicate diaphram in that valve. Cranking at any speed will not start the engine without fuel, and it takes a while for the pump to deliver to the carb. A well tuned flathead needs only a short push and a bump in 2nd gear to start, so speed of cranking is not the issue for that reason. Faster cranking does help the fuel pump to deliver faster, however. The coil is robbed of adequate voltage during engine cranking, that is the reason you'll see many engines start only at the instant that the starter motor is released, thereby freeing up the available voltage supply to power the coil. You may bypass the resistor on the firewall momentarily to provide the voltage that the staerter motor denies. You don't want to run with this higher voltage though, as it will burn the points or the condenser, and will shorten the life of the coil. Alan This message was edited by ford38v8 on 8-6-13 @ 8:19 PM
|
|
| TomO | -- 08-07-2013 @ 6:40 AM |
|
Slow cranking is due to inadequate voltage to the starter, poor grounding of the starter or a bad starter. If you have a voltmeter, you can do a voltage drop test to check out the connections and cables. You should also check that there is no paint on the starter mounting surfaces. This is the grounding connection for the starter. Tom
|
|
| supereal | -- 08-07-2013 @ 10:06 AM |
|
Hot starting problems almost aways are due to low voltage at the coil because of the starter load. If the coil input voltage drops below three volts, the output is too weak to fire the plugs enough to restart easily. Some install a switch to bypass the resistor, but because my old memory doesn't always tend to turn it off, we use the attached device to promote reliable hot operation.
|
|
| mike39 | -- 08-07-2013 @ 5:17 PM |
|
Thanks guys, Will do a little more checking. DB starter = DB electrical Pretty good starters for cheap. Find them on the net.
|
|
| TomO | -- 08-08-2013 @ 8:47 AM |
|
Mike, I checked their site and they do not give the current draw of their motor. It may be drawing more current than your battery can provide, resulting in turning the engine over slow. The Ford starter draws 150-200 amps and with a good battery and connections should turn your motor over very fast. I suggest that you use a good voltmeter to check the battery voltage with the starter turning and a voltage drop test of both the positive and negative circuits. Your battery should provide at least 5 volts at the battery to the starter. You should not have more than .1 volt drop at each connection, the total voltage drop from the battery to the starter should not exceed .5 volts, but in a good system, it will read about .3 volts. Tom
|
|
| TomO | -- 08-09-2013 @ 7:43 AM |
|
Mike, you may also have a timing problem. Check the cranking speed with the ignition off and when the ignition switch is on. If it cranks slower with the switch on, have your distributor checked over by a qualified mechanic. Tom
|
|
| mike39 | -- 08-10-2013 @ 4:23 PM |
|
Tom, We tried the ignition off and on, no difference. A local guy that's good with electrical says he can modify the starter so it will crank it faster. We will see.....Gonna try the hot start wire too. Mike
|
|
| supereal | -- 08-10-2013 @ 8:26 PM |
|
Trying to boost starter power usually results in a destroyed unit. As noted, if all cables are of sufficient size, connections are clean and tight, and the battery is strong, yet the starter is slow, it is time to look for a new or rebuilt unit. Be sure you have the brace between the starter and an oil pan bolt, as torsion can bind the drive in the ring gear. Worn bushings allow the armature to drag on the field shoes.
|
|
| TomO | -- 08-12-2013 @ 8:29 AM |
|
Mike, In that case, use a good voltmeter to check the cranking voltage at the battery and the voltage drop from the battery to the starter. If you need help with the voltage drop test. let me know. Tom
|
|
| mike39 | -- 08-13-2013 @ 6:04 PM |
|
Tried the supereal quick start wire. It helps! Still cranks slow when hot but it will start. Does anyone have a pic of the brace that's supposed to go between the starter and oil pan bolt ? I don't have that. I bet a lot of them were thrown away. Thanks, Mike
|
|
| TomO | -- 08-14-2013 @ 7:25 AM |
|
Here is a link to Dennis Carpenter's catalog page with a picture. http://dennis-carpenter.com/search.aspx?ss=starter&c=&pgnum=4&d=2 You can also Google 51A-11140 The quick start wire is a band aid and you may eventually have to find the cause and repair the problem. The purpose of the bracket is to keep the starter from twisting when engaged and causing the Bendix to hang up on the flywheel. It may help, but you may still have a problem with the starter running slow. Tom
|
|
| mike39 | -- 08-15-2013 @ 5:19 PM |
|
ordered the starter bracket...cant hurt anything to put it back on. As far as the quick start wire...I wouldn't call it a band aid. Mustangs in the 60's did the same thing but their wire came off a second small post on the starter solenoid. Anyone here use an aluminum radiator on their flat head ? Wonder if its worth the money ? If the cooling fan was up higher so you could use a shroud and pull air from the whole core im sure the stock radiator would work a lot better. Mike
|
|
| TomO | -- 08-16-2013 @ 8:21 AM |
|
An aluminum radiator will not cool as well as a copper radiator. The current cores do not seem to transfer heat as well as the Ford cores. If you have your radiator re-cored, make sure that they use a core with louver fins. You can use a shroud or a flex fan to improve the slow speed cooling. You will have to make your own shroud, they were not available for the pre-WWII cars. The reason that I call the quick start wire a "band-aid" is that there are thousands of flatheads out there without one and they start fine. Tom
|
|
| mike39 | -- 09-09-2013 @ 4:46 PM |
|
Update--- Griffin aluminum radiator helped cooling some. Not night and day better than the re-cored stock radiator, but some better none the less. The starter that a local guy worked on is great ! He added 2 more field windings. Helped a lot. It will crank a fresh rebuilt and hot flathead. The original starter had 2 field windings with space for 2 more. Guess Ford thought 2 was enough...but 4 is better ! Mike
|
|
| EFV-8 Club Forum : | https://www.earlyfordv8.org/forum |
| Topic: | https://www.earlyfordv8.org/forum/viewmessages.cfm?Forum=18&Topic=6383 |