I apologize if this is common knowledge but I did some searching and did not come up with much. I had a 54 m37 that had been sitting for years and was having trouble getting it started. I had spark but it was orange not blue. I did not want to spend money on new military style plug wires if I did not need to. Will Watson told me about using civilian plugs and wires with the waterproof factory 24 volt distributor. It was cheap and worked so figured I would share!
I ordered:
7mm solid core wires from Rock Auto part # 3602 - $12
AC Delco R45 Plugs - $1.50 Each
Cut the wires to length, wrapped electrical tape around them ONE time to make them fit tighter into the distributor, bent the inner wire over the outside of the wire then pushed it into the distributor. Then you take the boot and push it over the threads where the waterproof wire thread on.
Got it put together and the truck fired up! Hope this can help someone! I know it did for me!
The credit goes to the Morley MO Fire Department Mechanic. As I learned this trick from my brothers M37 Brush Truck. http://wawii.com/m37/DLW-80049099/
Will work for a while, chances are much better if you had acquired the correct terminals that actually snap into the inner cap towers. I've seen what you did tried many times, the eventual end result is burned and ruined inner cap towers. Sometimes mods work fine, other times not so much, this method, which falls short of doing the job right, is one of those not so much times. This method gets you by temporarily, then you get to replace a $45 inner cap, buy another set of wires unless you left them long enough to cut off the burned ends and start over. Spending approx. $5 more would have got you the terminals to crimp onto the cables and will snap snugly into the inner cap towers. Produces a far more reliable and longer lasting modification that isn't likely to leave you stranded or limping home with some cylinders not firing. The extra $5 and 5 minutes needed for a proper mod here will take you far in this instance.
MSeriesRebuild wrote:Will work for a while, chances are much better if you had acquired the correct terminals that actually snap into the inner cap towers. I've seen what you did tried many times, the eventual end result is burned and ruined inner cap towers. Sometimes mods work fine, other times not so much, this method, which falls short of doing the job right, is one of those not so much times. This method gets you by temporarily, then you get to replace a $45 inner cap, buy another set of wires unless you left them long enough to cut off the burned ends and start over. Spending approx. $5 more would have got you the terminals to crimp onto the cables and will snap snugly into the inner cap towers. Produces a far more reliable and longer lasting modification that isn't likely to leave you stranded or limping home with some cylinders not firing. The extra $5 and 5 minutes needed for a proper mod here will take you far in this instance.
Do you have part numbers or pictures. The plug set came with metal ends but I was told not to use them. I am open to doing it better but I am just working with the knowledge that I have.
MSeriesRebuild wrote:Will work for a while, chances are much better if you had acquired the correct terminals that actually snap into the inner cap towers. I've seen what you did tried many times, the eventual end result is burned and ruined inner cap towers. Sometimes mods work fine, other times not so much, this method, which falls short of doing the job right, is one of those not so much times. This method gets you by temporarily, then you get to replace a $45 inner cap, buy another set of wires unless you left them long enough to cut off the burned ends and start over. Spending approx. $5 more would have got you the terminals to crimp onto the cables and will snap snugly into the inner cap towers. Produces a far more reliable and longer lasting modification that isn't likely to leave you stranded or limping home with some cylinders not firing. The extra $5 and 5 minutes needed for a proper mod here will take you far in this instance.
Do you have part numbers or pictures. The plug set came with metal ends but I was told not to use them. I am open to doing it better but I am just working with the knowledge that I have.
Never buy a wire set, buy bulk wire, along with the correct individual terminals and boots for both ends. We have had various of these parts in the bin for years, would have to dig for current part numbers, etc. You can do that as well as I can at your local NAPA, CARQUEST, etc. Information concerning all these parts can be found in their ignition cable catalog.
MSeriesRebuild wrote:
Never buy a wire set, buy bulk wire, along with the correct individual terminals and boots for both ends. We have had various of these parts in the bin for years, would have to dig for current part numbers, etc. You can do that as well as I can at your local NAPA, CARQUEST, etc. Information concerning all these parts can be found in their ignition cable catalog.
I guess for the average guy who hasn't been doing this for years part numbers and or pictures would help. I know you are in business to make money so I would even buy the parts off you if needed. But so far I don' t think I could improve on how I did it with the information I have. I did look online at Napas 1000 page ignition catalog and didn't even see plug wires. Just caps, rotors, speeds sensors and such.
Ultimately I would like to go back to the screw on plugs and wires but I would need to save up some money. I would like to get it running and driving first and I still have brakes and lights to worry about.
MSeriesRebuild wrote:
Never buy a wire set, buy bulk wire, along with the correct individual terminals and boots for both ends. We have had various of these parts in the bin for years, would have to dig for current part numbers, etc. You can do that as well as I can at your local NAPA, CARQUEST, etc. Information concerning all these parts can be found in their ignition cable catalog.
I guess for the average guy who hasn't been doing this for years part numbers and or pictures would help. I know you are in business to make money so I would even buy the parts off you if needed. But so far I don' t think I could improve on how I did it with the information I have. I did look online at Napas 1000 page ignition catalog and didn't even see plug wires. Just caps, rotors, speeds sensors and such.
Ultimately I would like to go back to the screw on plugs and wires but I would need to save up some money. I would like to get it running and driving first and I still have brakes and lights to worry about.
Things like this are many times not on-line, you will have to go in and look at the paper catalogs to readily find such items. At NAPA, I think it will be shown in the BELDON wire and cable catalog. Really I would expect CarQuest has a better selection of these items, in many areas, they are better than NAPA. If I had part numbers at hand, I'd share them with you, but the stuff we have was bought in quantity years ago, and I do well to recall what happened yesterday. As far as selling individual parts, I would have had to furnish it all in order to know everything fits and works. Mixing and matching with other manufacturer's products does not always work out like we hope. One of my tech's used to be a NAPA Jobber, I expect he can maybe offer some part numbers that will help you, he has an amazing memory and knows lots concerning the older stuff, you know the kinds of things that cause the young counter guys to look at you like a cow at a new gate. I'll see on Monday.
MSeriesRebuild wrote:
Things like this are many times not on-line, you will have to go in and look at the paper catalogs to readily find such items. At NAPA, I think it will be shown in the BELDON wire and cable catalog. Really I would expect CarQuest has a better selection of these items, in many areas, they are better than NAPA. If I had part numbers at hand, I'd share them with you, but the stuff we have was bought in quantity years ago, and I do well to recall what happened yesterday. As far as selling individual parts, I would have had to furnish it all in order to know everything fits and works. Mixing and matching with other manufacturer's products does not always work out like we hope. One of my tech's used to be a NAPA Jobber, I expect he can maybe offer some part numbers that will help you, he has an amazing memory and knows lots concerning the older stuff, you know the kinds of things that cause the young counter guys to look at you like a cow at a new gate. I'll see on Monday.
I am not trying to be difficult on purpose. I am just interested in what you are recommending plus if this information is going to be out there for people would see I want it to be the best information possible. Also, this is the first vehicle I have owned with points (even though it doesnt have them now) so this is all new to me. What may be second nature to you is over my head. If you dont have part numbers than pictures may help as well. I appreciate your time and help!
Sorry for the delayed response here, just saw this question this morning the first time. First, the guy who worked here that was a NAPA jobber is not with us any longer, and I'm not as fluent with that info off the top of my head as he was. We have been short staffed by 2 techs for some time now with a tremendous work load; I just don't have the time to follow things online like I use to. Perhaps you can send me an email, mseriesrebuild@gmail.com better describing the situation you are needing to deal with; I'm happy to try and shed more light on your given issue as soon as I can.
The main problem is the industrial / military style spark plugs are obsolete and no longer being manufactured, and becoming hard to get or very expensive.
It seems that a viable commercial alternative spark plug for the 3.8 liter engine in the stock M37 is either an Autolite 295 non-resistor or Autolite 306 resistor spark plug. These spark plugs would take a "normal" spark plug boot on their end.
Per the attached spec the ignition wire is 5mm inside the conduit of the waterproof spark plug cable.
If a commercial spark plug wire is used I believe that a 7mm or 8mm spark plug wire (not in conduit) could be used.
The problem is on the distributor / distributor cap end of the spark plug cable.
Referring to the attached spec sheet, both ends of the military waterproof spark plug cable have ends that terminate in a spring; they do not snap onto either the spark plug or the distributor cap like a "normal" spark plug assembly.
When they are connected and the threaded cap on either end of the conduit is screwed down, they are held in place on both ends by the cap and the inner spark plug cable is pushed down with the spring on the end of the assembly making the final connection on either end.
If you look at the military distributor cap, the terminal towers are smooth with only a disc at the inner bottom of each tower where the spring connector on the cable meets with the disc to make the circuit connection. There is no mechanism on these distributor caps for the end of a spark plug cable assembly to snap into or mate to make a positive connection between the cable end and the distributor cap tower without using the outer distributor cap shell to screw the conduit end into to keep the connection from coming loose. If you were to try to make a cable set using regular spark plug wire I believe this is the hurdle that would need to be addressed; how do you terminate a "standard" style spark plug wire on the distributor end of the existing M37 waterproof distributor assembly in a permanent and functional manner?? The MS numbers for the parts that make up the waterproof spark plug cables are for design purposes only and can't be used to locate / identify the parts used on the waterproof ignition cables. So I don't know how you would even source some of those parts for experimentation purposes. Perhaps the folks who currently make the waterproof cables for some of the parts vendors could provide some of those parts; or perhaps they would be able to modify their assembly procedures for the waterproof cable sets by leaving the connection assembly as-is on the distributor side of the cable but terminating the other end in commercial-type 90-degree spark plug boot???? I guess anything's possible given enough time or money but it is sure a strange state of affairs when the military / industrial-style spark plugs used for years with this waterproof ignition system are no longer being manufactured.
Sounds like going around the world to cross the road here. The easiest way to do this is to change out the distributor to the civilian style, then use a standard plug cable and plug, You can change to a civilian oil pump that matches the civilian distributor shaft OR you can retain the military oil pump and install a military offset distributor shaft into a civilian distributor. No, I don't like either of these options as well as the standard military water-proof system. We bought up several hundred spark plugs just before they went obsolete in order to keep building standard mil-spec systems for our restoration projects. When everything is depleted, then we too will be forced to do something different at which time we'll cross that bridge and make the best decision we can.
The other option is to use the military distributor, military wires and civilian sparkplugs with a set of the adapters that several people are making and selling.
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