MikeC5

Copy sent. If anyone else still needs one let me know.

I completely agree Dave!

Outstanding! What a fine collection of DBs. I find the ambulance and safari wagon especially interesting.

Well at least you should have good local access in NYC metro area to a shop that still knows how to repair generators. I would be interested to hear what they say the problem is.

Hi Gary, You can switch to the lowest ohm scale for these (2K) but it does appear that your starter field coils are OK. As for the charge (shunt coil), I was mistaken on checking it with the fuse in because leaving it connects to ground . Also, the shunt coil connects to the 3rd brush which is the one on the underside (the one not seen in your photos). If you want to go ahead and check it connect one lead to this brush and the other to one of the fuse terminals (I think it's the one you have the lead on in 3rd photo). If you get nothing, try other terminal. As for the starter, with field coils checking OK and brush connection and brushes OK, the only thing left is the armature/commutator. If you can find a generator shop that actually repairs generators, they have a tool called a Growler that is used to test armatures (but it must be removed from gen). While you have the brushes out, it may be worth trying to clean up the commutator with fine sandpaper (not emery paper). I've read that sometimes people over-oil the end bearing which results in oil on commutator which can cause problems too.

This thread may be of interest. I am using a mylar capacitor.

Vulcanized? I thought that was a process for rubber. Are they gluing on the linings with vulcanized rubber?

I suspect the crack was from water freezing and not just from normal heat cycling. I like the JB Weld or maybe the Belzona. In days gone by I had successful radiator repairs using JB weld. I'm thinking the different expansion coefficients of cast iron vs. epoxy will not be that big of a deal since the temperature rise is only something on the order of 120 F or so. If you can get to the inside (maybe sandblast?) I would patch inside and out. I would stop drill the ends (through thickness) just to prevent it from growing. Maybe 1/8" diameter (that's what I've seen used on some aircraft nozzle repairs). I suspect the issue with welding and the need for slow cooling is grain size and martensite formation. Fast cooling gives smaller grains which tends to make things less ductile. It can also cause martensite to form which can make cast iron much harder but more brittle and susceptible to cracking. Slow cooling (over a day or two) controls these factors. More massive parts may need much more cooling time to prevent cracking; just from the cooling process inself.

They do appear to be from a 24 - 26 Dodge. That is a very good price and would be worth the hassle of international shipping.

Thanks Jesse.

Did you check valve clearances? If either valve has too little clearance and isn't closing fully it can result in a low compression reading. Do you know how to check them?

What did you re-line them with? I don't see the rivet heads; how are they attached? It may be necessary to re-shape them to more circular by careful bending. I think it's better to do that before re-lining them but you may be able to tweak them. It is tricky to get a uniform gap all of the way around.

If you know how to check continuity you're halfway there! When you have continuity, the needle swings all the way to left (or is it right?). That is essentially zero resistance (resistance to current flow). When the meter leads aren't connected to anything the meter reads 'infinite' resistance . The multi-meter has several scales on the face and you need to identify which one is for ohms (ohm symbol looks sort of like an upside down horse shoe). Remove the SG fuse. Now take one meter lead and hold it on the post on the left where the cable would attach to go to starter switch box. Touch the other lead to one of the wires going to any one of the brush wires. If no response, try the other brush wires. One of them should give a meter response that will be close to zero but not quite zero. If you study the scale you should be able to estimate resistance but the actual value isn't that important; it just needs to be low (which tells us the wire winding doesn't have a break in it). Now hook one meter lead to the ground post over on the other side of SG (close to engine block) and the other lead to one of the other two brush wires (not the one just measured). One of these other brush wires should give a meter response and similar low resistance to the first one measured. If you can't get one or the other to read it means there is a wire break or bad connection somewhere and the starter needs both field coils to operate. You can also test the 'shunt' coil winding which is used for the charging part of the SG (which is the one with the fuse). Re-install the fuse and connect one meter lead to the fuse and the other to the brush that gave no response in the previous two tests. It should show a meter response similar to the starter coils but a bit more resistance. If the field coils check out OK then the problem probably lies in the commutator. It's kind of academic at that point since repair of field coils/armature isn't really DIY.

Sometimes you see them come up on Fleabay. You might also try Myers Early Dodge.

If you have a crank, I would try rotating the engine a few degrees in case the armature has a dead loop on the commutator (and it happened to stop with one of the brushes right there). If that has no effect I would get a volt-ohm meter (or digital multi-meter) and check the field coil windings (labeled series winding here). This diagram shows what and where to measure. The starter brushes can be identified as a little thicker than the 3rd brush. I can't remember the resistance values I got on mine but it should be only a few ohms (1 - 3 iirc). If reading is off scale it means an open circuit (broken wire) in the field winding and that's bad. If you decide to make the measurements, the brushes should either be disconnected or slip a piece of thin cardboard under the brush to insulate it from the commutator. If you're lucky you may have an old-time generator/alternator repair shop nearby that can actually rewind the field coils. Otherwise, check with Myers for a rebuilt unit (or maybe a good used one).

Thanks Pete. I appreciate the info. Mine are repro brackets I got from Myers (I think). A metal hook does sound like it would be more secure. It will be easy to make a hook that rivets to the bracket. It does sound like your 2nd bow is very close to what I have. (I'll check inside dimension).

OK now that everyone is back from Hershey... In addition to the above question I'm hoping to get some detail on what material is used for the anchor straps where they connect to the anchor tabs on the tub (see photo). Also what is dimension from body anchor tab to clip? In case anyone is wondering, I took a retired top bow, shortened it, sliced it lengthwise to 1" tall, used a heat gun and clamps to contour it to the body and then added two 1/4" thick strips of oak (more heat gun, clamps, Gorilla Glue) and voila!

You've disconnected the cable from the SG and are jumping it directly from a known good battery? It should turn. I hope the rotated terminal didn't short and cause damage when you tried to start it. If you are certain you had a good battery connected and got no response, you will need to open things up and see why it isn't energizing. The first thing I would look at is the condition and connections of the brushes. This can be done with the unit still mounted to engine. You have to loosen and remove the sheet metal hoop cover on the aft end to do this. Look for broken brush wires or broken springs (there are spring loaded arms that push the brushes against the armature (the part that rotates))

Do you mean the square copper contact has spun? Did it damage the insulating 'cardboard' underneath the contact? The copper contacts must not touch the anti-rotation plate or the base plate (which could cause a short when you push start button). There should also be an insulating washer that keeps the copper stud threads from contacting the base plate. This photo is after I finished converting from the cut-out relay to a diode but you can see how the main contacts should look).

With engine idling, the ammeter should be over on the charge side. How much will depend on how the 3rd brush is adjusted. Mine is up around 12 amps with headlights off, 6-8 with them on. As you drive, increased engine speed will lower output. I have mine adjusted so that at 35-40 mph, charge drops to just slightly positive with headlights on. I don't drive enough to have any issues with overcharging the battery.

Hi Pete, my car didn't even come with top sockets much les bows. I recently found a set for sale and only have clues.. As I mentioned, number 4 does have a part number, 1422, and number 1 bow has P/N 1230. Both numbers do correspond to the DB master parts list. Unfortunately, bows 2 and 3 do not have any markings. Can you tell if width of bow 2 is noticeably shorter than 1?

Does anyone happen to have measurements of the bow widths? I'm getting around 58 & 1/2 on bows 1 and 4 but 2 and 3 are shorter (number 2 is only 56 & 1/2 and has a different curvature (similar to this photo). Also, number 4 bow is about twice as wide in cross section as the others and has a contoured shape to make the horizontal to vertical transition more graceful (I guess). I can just about make out a part number on it which looks like parts catalog number 1422 so it may be original.

Do you mean reposition the pinion/rack engagement? If you needed choke to run at all, I'd say yes. If it's off the other way (way rich), the plugs should show/smell it. Half inch sounds about right on advance linkage. It should be pretty obvious if you are getting a lot of lost motion somewhere. The valves on mine had way larger gaps than they should have. It still started but I never drove it that way so I'm not sure how much impact on power. Be vary careful to not set gap too tight or when warmed up the valve may not close completely (a good way to burn valves).

That is a pretty spiffy looking roadster. Nice proportions.

Nice! Wish I had neighbors like that...