Driving to job this morning, sniff the whiff of antifreeze. Get pulled over and its bubbling/building pressure in the radiator. Fortunately I was only down a little bit of antifreeze, and was able to turn around and back to shop. Do the Detroits have a head gasket, or are they just o-rings on the liners? I'm assuming thats why I'm getting compression in my water, or else I've got a cracked head. They only break if your using them. At least I got it back to the shop and can fix it there.
The only coolant in a two stroke Detroit engine is within the head, no coolant in block, no coolant going by head gasket (they don't have head gasket anyway). With pretty much any Detroit, if you get coolant into combustion chamber or pressurizing radiator, you have a cracked head.
Your kiddin right?
Thanks Willie, I was afraid that was the case. Probably end up with a reman head then. I've got the hood panels, exhaust, valve covers, and most of the front of the engine apart. I think in a few hours in the morning we should be able to get the head off. One of my operators has a neighbor who is a Detroit man from way back, he said if we get it all out and a gasket set, he'll help us put it back together. I'm not much of a engine man, I probably know just enough to be dangerous. It's hard to find anyone who does know anything about 2-strokes. The younger techs just shake their heads when I talk about them, if they can't plug it into a computer, they don't know whats wrong, let alone know how to fix it. I've got a big cam cummins on the floor of the shop that I was going to put into it this winter, but I've been too busy. I'm too busy right now to even think about shutting it down for a couple weeks to do a big change, so I'm going to just fix the Detroit for now. I really would love to change from the 210hp detroit, to the 400 hp cummins, with our hills in our area, but every job I miss while its down, is a job I don't get back.
Or a leaky injector tube
Nope, not kidding. Yep, was scratching my head knowing there was one other spot that could leak, totally forgot about injector tube.
Yair . . . Bluox. The block on a Jimmy is essentialy an air-box. The liners are surrounded by pressurised air from blower/turbo . . . ports in the liners are uncovered by the pistons. I loved those engines but I drove them more than wrenched them. Lots of good info on this board if you care to do a search. Cheers.
Willie, I agree with the cracked head (I wonder if its been run hot) but Im confused with your other comments, no coolant in block. Its been hot here, today, maybe Im missing something, I cant stand the heat like I used too
Try Diesel Engine Parts crane op, they do quality work. http://www.dieseldhp.com/ You're right Willis, don't know what I was thinking, there's a small amount of liner has coolant surrounding it, the very top part of liner. It's sealed by o-ring in block to prevent coolant from entering air box. I've rarely seen one of these o-rings fail, and typically when they do, they will flood air box from cooling system pressure, not enough pressure generated by blower to pressurize cooling system. Typically when you have excessive pressure in cooling system, it's caused by cracked head, which Detroits are bad about, or leaking injector tube. I've rarely seen a liner crack on one, I suppose because they're so darn thick. Pic of 4-53 engine block, small chamber at top of block, above air box, has coolant in it. Here's a pic of underside of head.
Right a 53 does have water around top of liner but a 71 is dry there is water in block around liner but doesn"t touch any part of liner. jr
No worries jr, was simply correcting and inaccuracy I made concerning Detroits that Willis aptly pointed out. Ain't the first time I've made a boo boo here on HEF, just want info to be accurate.
Holy crap Willie i read the start of this and your first post and nearly fell off my chair!!! Lucky i kept reading! I agree, injector tube, crack... fingers crossed on the tube, cheaper to fix!!!
LoL, sometimes I just have to laugh at myself Zed.
One of my guys got the head off today, and things don't look too good. Third hole has been blowing out between head and block, evidently the liner was not quite high enough for the crush fit. The piston is cracked on the top, with a hairline fracture running toward the center. I imagine the compression was blowing over to the water holes in head, leading to bubbles in the radiator. My first thought this morning was to go ahead with my repower project, unless it was easy/cheap/quick to fix the Detroit. I see no reason to only fix one, or possibly two pistons (another one has a small bad spot), and do liners for them, and bolt it back up. If I do one piston, I'm doing all of them, and then your talking a complete rebuild, and some down time. Just to fix it with 210 hp. The bad of the repower is even more down time, because nothing is the same. Different motor is longer, taller, trans is longer. Starter, powersteering pump, air compressor, fuel pump, exhaust, intake, front pto, front and rear motor mounts, and throttle and transmission linkages are all different. But I'd end up with over 400 hp. Which would really help out in the hills. A few pics of the Detroit
Yeah, that fire ring on #3 looks pretty much smoked. Inframe of a Detroit isn't bad to do, so long as the crank is in good shape. Repower with different motor (more hp) is for sure desirable, but sure is a PITA to change everything from Detroit configuration. Do keep us posted.
I would Inframe the 6-71 and when ordering the kit speck it out for a 6-71-T.Add the turbo & injectors and you might be surprised with the power increase.I ordered my last detroit kit from www.btmccorp.com and I am very pleased with it. Good luck on the repair.
Got the old motor pulled, just after 5 this evening. Left this morning at 5am to drive two hours to a guy who had a "great" take out engine. Got there, waited 1/2 hour for him to show up. He decided he wanted to keep the transmission that was still bolted to it, and I watched his helper break off two bolts in the bell housing. Like I need more work. Then, they pick up the motor with the loader, and 1/2 gallon of water and a drip of oil comes pouring out of the corner of the block. Guess its been out in the rain with no intake cover, filled with water, froze this winter, and cracked the block. Told them just to set it back on the ground and keep it. I'm having more trouble trying to find a motor set up like mine. Mine has the water rail and exhaust on the drivers side. Exhaust is centered with a 90degree up elbow. Alternator mounted low on the front drivers side. Blower is passenger side, with a centered elbow up intake, not offset to the rear or front. My fuel pump drives from the back of the blower. Starter mounts low pass. side driving into rear gear box. Air compressor and and power steering pump mount on the rear gear box accessory holes. Also have a extra plate on the front crank pulley for my front pto. Latest idea is to actually rebuild mine, its set up the way I need it, and there are 500 different set ups for the Detroits (seems like it in pictures). The one I looked at this morning the water rail and exhaust were the wrong side. Fuel pump drove off the rear acc. box. power steering was front drivers side, air compressor was rear, with a through pulley for the alternator. Starter was drivers side, blower was offset intake to the front. Saw pics of one today from a bus, it looked like it was set up to run on its side. If I reman it for the turbo, is that just bigger bearings with heavier crank, pistons etc. Would my small box 13 hold up to it? I would imagine you have to add the turbo and injectors right away, So then I would need a different intake and the turbo exhaust too. Are they aftercooled, or water cooled intake (like a cummins big cam?). I'm not dealing with a after cooler set up, I don't have room. Thanks for all the help guys, I'm going to try and have a plan for monday. Also, I will say God has been watching out for me, I purchased a second 25 ton crane less than a week ago, without it I would be in a world of hurt. But I do have a week long job thats supposed to start a week from Monday, that I was going to use my 35 ton for, I don't see how I can have that done by then unless I find another take out motor. I don't see anyone rebuilding my detroit in three days, nor can I retrofit the cummins in that time. Thanks again everyone, remember keep smiling.
Too bad you weren't closer I've got a real good one. jr
Just to encourage you a bit crane op, since you're in a time pinch, one thing that's nice about the old Detroit is that it's a very friendly engine to drop new pistons and liners in it to give it a freshen up. If the crank is good, drop some new pistons and liners in it, slap on a reman head, and you're good to go.
If you want to get it up and running real quick, maybe just get a head install kit and put it back together? Correct me if I'm wrong, but it only failed 1 compression seal on the top of the liner? The Piston/liner is still good? If you do that, it will be running again in a day easy. Then if you want to rebuild it/upgrade/repower, schedule it for when it suits you.
ooops I just checked previous posts and see that you have a cracked Piston, so please disregard my last post! however, you can still just replace 1 cylinder kit to get you up and running. This will also help the original problem where the liner height may be a little low. So now you just need a Cyl kit (plus shims maybe), sump gasket, head install kit.
My understanding of the 6-71-T is the pistons & injectors are different from the 6-71 engine.We are looking at a 6-71-T now to install in my TM 250 Grove.I'l try to get some more information on it Crane Operator.You will likely need a thicker raidiator core to keep things cool on hot summer days if you go with the 6-71-T or Cummins re-power.Thats the problem on these crane chassis is the radiator sets down between the frame rails so the only way you can go is thicker core or run two cores in tandem.Like Willie59 said these engines are made to be overhauled ,we have "inframed" them in parking lots and on job sites.We had to overhaul the Wabco 8-V-71 last summer on the dam at a lake job.They are allot of fun,keep us posted Crane Operator. HeavyEquipmentForums
I feel kind of bad because I never updated this post. I've been busy. I decided against repowering. I really needed the crane, and I didn't have the time myself to do it. I found a engine rebuilder who specialized in bus engines for years, and a lot of them used to use Detroits, and he seemed to know what he was talking about. We pulled the motor, I called the guy on a Monday, he said if I have it on Tuesday morning, you can have it on Thursday evening. No "well I'll look at it next week and then order parts" b.s.: pick up on Thursday evening. I brought it too him, and he had it ready on thursday. They weren't cheap, but I had my motor. They were great to work with. I actually had more trouble finding a clutch, than the motor. The truck parts man got the wrong one(after a week of waiting for it), and it took a extra two days, and a trip to Kansas City on my part to get it. I had about four days of working, and two weeks of parts rounding up, and I was back on the road making money. Every time I drive it, I regret not repowering, but the money I put into the Detroit, means I live with it for a while. The worst thing was that the Monday that I talked to the engine rebuilder, I recieved a phone call from one of the operaters "I think this crane is stuck in two gears". I had just finished taking the other 25 ton to a jobsite and was planning on taking the Detroit to the engine man, intead I told him not to move that one, and I was on my way. Motor out of one crane, transmission out of another. When I got to the crane, as I stepped out of my truck, I could smell the clutch. So much for not trying anything (or else he did a lot of trying before he called me). I popped the top off the transmission, and a prybar popped it out of 1st. By using the clutch and the throttle to spin the trans a little, I could get it to "fall" out of reverse, but the lever wouldn't take it out of gear. Of course I had work scheduled all week for that crane, so I had the operator deliver the motor to the rebuilder, and I (and I still don't believe I managed) limped that crane to six different jobs that week, with it not able to come out of reverse by the lever. By watching how I backed in places, I'd let it roll and drop itself out of gear, all the time praying that it would. That saturday two of us put the motor in the 35, and two other guys pulled the transmission on the 25. I finished bolting up the 35 on sunday and it went to a job on that Monday. I had a clutch for the 25, and combined two transmissions to get one good one, and the next saturday me and another guy put the 25 back together. I'm so thankfull for the guys that help me work on stuff, because I couldn't get it all done on my own. And believe it or not, I'm still having fun.
That's the spirit ................ good on ya ......
pics of pulling motor, that's my buddy John guiding me. We left the trans in the crane, used the A frame to hold it up. It was a load on my forklift pulling it, and worse when it went back in because then it had the head installed.