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struggling to resurect an m37

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  • struggling to resurect an m37

    I bought a 1962 m37, planning to use it as a plow truck. I overlooked its poor condition because I had a bit of the power wagon fever and was excited to get one. last registration on it was 96 and apparently it was a NY state plow truck of some sort. So been sittin for about 14 years. Well a month lator and it is starting to snow and she's still not going right. I guess it's all about my attitude and how I approch something that determines how frustruated I get.

    I thought I would just clean the carb and away we would go. Not so much. I got it home and threw a couple batteries in it and it rolled over. good. then pulled the plugs and found I had no compression on a 3 cyl. So I drained the oil and filled the eng to the top with kerosene for a couple days. drained it and still no compression on 3 cyl.

    I pulled the head and soaked all cyl with ATF and pulled side covers and soaked valve stems with PB blaster. got everything freed up. In the meantime I tore the carb apart and cleaned it spotless in the parts waher. cleaned and gapped the points. made some regular wires connected them to the militarty dist. put autolite 306 plugs into it. made a gas tank out of a jerry can and put it in the cab took the fuel pump off and cleaned it out. Got it running. cool... gapped the power valves and put front fenders back on.

    made some old dump truck tires fit, fabed up powr steering and a plow bumper... put in joysitck for plow... put brake lines on it and bled them out, welded up the rotton driver side floor pan to the cab would be stable, made some running boards.

    In all this excitement my 4 year old turned on the ignition on and it got left on all night. when I came out the next day it would not start. I put a NEW set of points and cond in it and it will only run on 3 cyl. no spark on 1-3-5. It seems like an alignment issur with the dist cap and rotor. put in new cap and rotor. same. pulled dist and put in new bushings and reamed out and lined everything up just tits and it is now running again but no power. no power. If i rev it is slowly come up to speed, almost like it's missing. compression is front to back 95#-95#-95#-95#-90#100#, Is that good? i read somewhere that min is 90 then someplace else it is 100?

    Now I am thinking maybe my coil could be weak. It measures15,000 ohms cold /15,200 ohms hot on the secondary resistance and 12.44 ohms cold/12.8 hot on the primary resistance. Maybe that capcitor on the power wire to the dist could be bad.

    a freind that likes to work on old flathead tractors assures my that a bad condensor will allow a flathead to run but it will have no power. He said "do you have the right spark" I said well I got spark. He says ya but is has to be the RIGHT spark. Mine is kinda red not relly blue.

    My timeing pointer was missing so I made one and did the best I could to locate TDC. I may be off a little but not more than 2 degerees. I have tried the reccomended 2 btdc 4 btdc and all the way up to 20 Btde and performance is terrible. Yesterday I put in a set of autolite 303 plugs gapped to .35 A new coil is on the way and when it gets here Im going to put it in and remove that little capacitor in the dist pwr wire.

    But I thougt I would put what I have done on here so maybe a fresh set of eyes could give me some Ideas of what direction to go into next. the truck has 19" vacume at idle and I did a sniff test with propane to try to find any vacume leaks. I did put a regular PCV valve in place of the fording valve but when I put my had on the oil pipe it dosent' suck on it. the blow by isn't too bad. the truck fires right up and idles with a miss here and there but just falls flat on it't face when you try to ask for some power. HELP!!!
    Here is the culprit

  • #2
    I would throw a new capacitor in it and replace the wire from the points to the coil. Just because it is a new cap, doesnt mean its good. If it was running good before the key left on then that is what I suspect first and foremost. You should have a fat blue spark, a small reddish spark is indicating weak ignition system which may or may not be the coil. Since you have one coming I would go ahead and throw it in, but replace the capacitor at the same time so you dont stand burning it up as well.
    I know i'm probably not much help, but hope you get somewhere with it soon.

    Comment


    • #3
      The breaker points manufacturers like to put the spring on the points in the box the way its convenient for them, NOT the way its supposed to be. If you didn't assemble it correctly you will have very little tension holding the points closed. It would probably run as you described.

      Comment


      • #4
        hmm, I will look at that when I pull the dist out.

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        • #5
          Well, you got my attention with compression readings; I've seen people spend hundreds of $$ on items just like you have not really paying attention to the compression #'s. The fact of that matter is this; 100# is border line, maybe or maybe not run without skip, but will be weak on power for sure. 90# is not acceptable, if it runs, intermmitent skipping is very probable at the best. It is also highly likely that some cylinders may be dead as a result. These readings are not good in any engine application, especially one that will be expected to pull the extra load exerted by plowing snow.

          Some will say I'm stupid, no problem, I'm used to that; but facts are facts; and we have serviced a lot of 230 engines. Compare the above paragraph to the experiences you have written about here on this forum over the past 2-3 weeks. Does anything look and sound familiar? Even if the electrical stuff gets the firing issue straightened out; if your compression #'s are accurate, reality must kick in right about here; you are looking a much needed engine overhaul right in the face.

          Comment


          • #6
            charles, do you think I could just pull the oil pan and drop my pistons down throught the bottom. deglace cyl's and put pistons back in with fresh rings. lap valves and put head back on. My question is how robust are the bottom ends? when you tear them down for a rebuilds in your expierence does it usually look like the main and crank pin bearings have a lot of life left in them? truck has 52'000 miles on speedo but I have no idea of it's actual maintence history.

            Comment


            • #7
              Originally posted by gusbratz View Post
              charles, do you think I could just pull the oil pan and drop my pistons down throught the bottom. deglace cyl's and put pistons back in with fresh rings. lap valves and put head back on. My question is how robust are the bottom ends? when you tear them down for a rebuilds in your expierence does it usually look like the main and crank pin bearings have a lot of life left in them? truck has 52'000 miles on speedo but I have no idea of it's actual maintence history.
              #1 the pistons can't be pulled from the bottom, must come out the top. Getting a decent job without boring the cylinders is slim to none, my strong advice, do it right or don't waste your money.

              #2 Just lapping valves only is not good at all; the seats will need grinding at the very least, and the valves usually don't have enough margin after grinding the seats and valves. Replacing with new is best. The exhaust seats should be changed to hi nickel seats for unleaded gas while you are in it also. The valve guides will be egg shaped, don't forego replacing them and the springs. Install .030" valve spring inserts (shims) to overcome spring heat set issues.

              #3 Surface the head and check everything for cracks, block, head, crank, cam, and manifold assy carefully.

              #4 Surface the flywheel and install a new clutch and pressure plate, pilot bushing and release bearing; your snow plowing intentions will need that. Also surface the manifolds as an assembly, don't forget to replace the hot spot gasket where the manifolds meet.

              #5 If you have not rebuilt the fuel pump and carburetor, do that also. Be sure you use a fresh pump rebuild kit, NOS will not hold up. It will dump gas into the oil pan and you will dump a new engine in minutes as a result. Install a new 180* thermostat.

              These are the bare minimum issues that will need addressing in my opinion, there is a good chance you may see more when you get into it; LOOK CAREFULLY.

              Comment


              • #8
                Originally posted by Charles Talbert View Post
                Well, you got my attention with compression readings; I've seen people spend hundreds of $$ on items just like you have not really paying attention to the compression #'s. The fact of that matter is this; 100# is border line, maybe or maybe not run without skip, but will be weak on power for sure. 90# is not acceptable, if it runs, intermmitent skipping is very probable at the best. It is also highly likely that some cylinders may be dead as a result. These readings are not good in any engine application, especially one that will be expected to pull the extra load exerted by plowing snow.
                I'm gonna be the dark side here and disagree with Charles' first point for a moment.
                My first example will be the Kawasaki V-twin engines powering our lawn equipment where I work. These engines are pull start, and therefore include a compression release "bump" on the cam, which is basically just an extra small lobe on the intake valve right at TDC. Because it is built into the cam, it never goes away while running like an external compression release will. When hand cranking you will find compression readings in the 50PSI range. Plenty to not only fire on, but to run on. I have in fact run one of these engines on only 1 cylinder, with a compression gauge plugged into the second hole. At idle the engine operated at about 100 PSI. This was a fairly fresh built engine that ended up having a bad coil and a cracked intake manifold.

                My second example is an old Kawasaki 125 2 stroke dirt bike I had as a kid. Being a kid, while installing new rings onto an old piston to go into a worn out cylinder, I broke one of the rings. Oh well, slapped it together and tried to get her to run (free bike, $20 in rings, blew the budget. You know how it goes). The only way to get the beast to start was to pull the spark plug and drip some oil into the cylinder. Only then would there be sufficient compression to get it to fire up. Once running there was never a problem, plenty of power and everything. While yes, there is oil in 2 stroke fuel, it is only a 1:50 ratio, which means there really isnt that much oil in each intake stroke being pulled into the cylinder. Certainly not enough to keep sealing the ring like the initial drops of oil did. It was the piston speed that raised the compression level high enough to run.

                In reality 100 PSI, especially cranking the engine over with a battery that probably isnt new, with a starter that probably isnt new, with cables that probably have some corrosion and internal resistance, so turning at say 250RPM+/- is not that terrible. Were all the plugs removed and the throttle held wide open? We don't know. Once you get those pistons slamming each other up and down the compression readings will rise.
                Ever seen a flat 4 air cooled motor converted into a self powered air compressor? I have seen one that had a bad shut-off/bypass valve on it. Blew the 200 PSI certified tank to bits. As some of you may know tanks are certified at about 70% of actual capacity. Like all commercially available equipment they are designed to withstand 125% of ratings. So in essence that tank probably blew at 250+ PSI, out of a VW engine that had a 7:1 compression ratio. New they crank out 125PSI in compression tests and this pile was faaaar from new.

                Just some bits to chew on.

                I think that because you say it was running well before the key was left on that it is almost certainly ignition related. Your motor may be a bit on the tired side, but still capable of performing the tasks you desire. When the compression gets to the point where it will not start by itself (needing oil in cylinders, etc.) then that is the time to tear into it and fix it up.

                Now as far as the rest of Charles' advice, on what to do in a proper rebuilt. Absolutely! If you are going to go in there and spend some money, do it all, and right, the first time and you will never have a regret. Sure, the farmer way of just patching it may get you going for a while, but in the end you are guaranteed to have another problem with it and it will be at the most inconvenient time in the world (right in the middle of the driveway).
                I understand that you are on a budget and only want to put into the rig as much as you have to to get it operational. Going all new ignition will be money well spent either way.

                Comment


                • #9
                  I read the above post and I am not real sure of the relationship of a small Kawasaki modern engine and a clanking iron lump like the old dodge fit together.
                  But doing the "quicky" just sticking in new rings is a lot of work and has a very high chance of ending up a disaster, a very expensive disaster. Just getting the stinking head off without snaping off bolts that have been in there for 60 years is a blinking miracle because some of them go down into the water jacket and rust away into an hour glass shape and snap at the thin spot.
                  There is almost no chance that the cylinders are round any longer and on top of that they are no doubt cone shaped. Wide at the top and narrow at the bottom.
                  Gapping rings to work on cylinders that are tappered is imposible. If you gap them at the top they will bind up tighter than a Gnats A** streched over a rain barrel at the bottom and dig in.
                  Gap them at the bottom and they will blow by . Gap them in the center and you probably will end up with compression like you started with ,,maybe.
                  Just a thought.
                  I really hate to say this but,,been there done that and it was a disaster.
                  Alan in North Central Pa.

                  Comment


                  • #10
                    some interesting replies, I had the head off before I tried to start it to unstick valves and soak every thing with atf. Through some miricle I got the head off without any twisted off bolts. I just can't help but think this thing is not a swiss watch, it is not a race motor. it is just an old truck for around the house. I have to pick my battles. I can understand your approch charlels. but you are in a different league than me. If i attempted to put every thing on this truck (let alone my life) back to book specs I would be working on stuff for the rest of my life. I pick the worst stuff and just put out the fires. After a couple of years things start to slow down as I get them caught up. money wise I could get away with a set of rings and a set of rod bearings, the whole operation would take about a couple days after work to tear it apart and then a weekend day to put it back together. that doesn't seem like to big of a gamble to me. And even then when I get the head off and the pistons out I could take some measurments and detremine if I should do a proper overhaul or throw it back together. we will see how I feel about it next spring. maybe I won't like the truck after running it for a season. right now the only thing I'm not likeing is the wide turning radius. I am haveing fun with the new photobucket account and the camera so here is another pic from before I tried to start it for the 1st time.

                    Comment


                    • #11
                      If you got the head off w/o snaping anything it may be because some one had it off not too long ago or you are one of the luck ones.
                      You are right about not wanting to sink a ton of money into a truck that at best is worth 6 or 8 K if it is in real nice shape. And you may not like plodding along at 45 MPH with your foot to the floor, Ok 50 MPH if you catch a good tail wind on flat roads. We wont talk about going up hills. If you hit a 15% grade that is more than a 1/4 mile long you end up in second gear and 20 mph.

                      Comment


                      • #12
                        Originally posted by Kaiser2boy View Post
                        I read the above post and I am not real sure of the relationship of a small Kawasaki modern engine and a clanking iron lump like the old dodge fit together.
                        I could have gone to the other extreme and brought up the old hit and miss motors that were often used to power industrial equipment in the late 1800's. How accurate do you think parts were produced and machined in that era?

                        The point I was trying to make is that even in more modern, tighter tolerance engines 100 PSI is plenty to run on. 50 PSI will get them started so the OP's 90 PSI ratings are not something that worry me.

                        Comment


                        • #13
                          well being that it was operated by the highway dept. I can look at it 2 ways, one is it was used as a plow vehicle and must be beat as it is such hard service for a vehicle. or on the other hand a highway dept is better than a regular owner because they actually have a scheduled maintence dept that changes oil and seals and such. I don't know. there is a little rubber tube that drains that air vent in the firewall. it must have been cut because it was draining out on the top of the engine. the back 3 spark plugs were acually rusted off, but they still came right out. weird

                          Comment


                          • #14
                            I went back and read the OP. If he is getting 95 to 100 psi on a cold engine and it starts and runs ok , let it be.
                            You are right .
                            The clattering lump of iron in the Dodge is probably better suited for agriculture use.
                            I had mine totaly rebuilt and it looks great , starts like it was brand new and runs as smooth as silk. It is still a whimpy motor that has difficulty on hills.
                            But its fun when not on a hill.

                            Comment


                            • #15
                              engine was at normal operating temp, throttle was pinned wide open, all plugs were removed during compression test.

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