mfpdm Posted December 2, 2008 Share Posted December 2, 2008 So you may remember awhile back I pick up a rebuilt engine for cheap that had never been installed or fired up. Only downside was that it sat for ten years and it would not turn. I figured maybe the rings had rusted to the cylinder walls. However, today I finally pulled the head to find... Only a hint of surface rust that wiped off and a dead spider. I just don't see the rings as being the problem. On the under side it looks just a good with a little surface rust but not on any bearing surface. I thought maybe the timing chain, but I can see it and it looks fine as well. So...WHY WON'T IT TURN! :headpop: Any suggestions on what to pull next? Bearing caps on the cylinders or on the crank? I've also soak everthing with penetrating oil of every kind before and after head removal. Also gave the cylinders a smack with a rubber malet and still nothing. My son asked if there was a packing pin somewhere and I laughed, but hey, is there one? :cheers: Link to comment Share on other sites More sharing options...
redneck23ms Posted December 2, 2008 Share Posted December 2, 2008 whoever assembled it may have put a rod or main cap on backwards. if one or several are on backwards it will not allow it to spin over. Link to comment Share on other sites More sharing options...
mfpdm Posted December 2, 2008 Author Share Posted December 2, 2008 I wouldn't think this the case. I should have mentioned that it was a professional rebuild from NAPA. I would hope they turned it after it was done to show the customer, but here's some pic's of the underside just in case you can point anything out. Some are big to get all the detail. Link to comment Share on other sites More sharing options...
ncmudslinger Posted December 2, 2008 Share Posted December 2, 2008 That thing should turn. get a longer pipe :yes: Link to comment Share on other sites More sharing options...
ncmudslinger Posted December 2, 2008 Share Posted December 2, 2008 I'm originally from Salisbury and have known the head machinist from Salisbury automotive since I was knee high to a grasshopper. I seriously doubt he let anything out of there that wasn't right. I would pull a rod and main cap Link to comment Share on other sites More sharing options...
Redramman Posted December 2, 2008 Share Posted December 2, 2008 I'm thinking that the bearing clearance on crank or rods is too small (they fit to tight). Link to comment Share on other sites More sharing options...
mfpdm Posted December 2, 2008 Author Share Posted December 2, 2008 I'm originally from Salisbury and have known the head machinist from Salisbury automotive since I was knee high to a grasshopper. I seriously doubt he let anything out of there that wasn't right. I would pull a rod and main cap Wow what a small world. :eek: I would go with the big pipe idea but I would snap that bolt right off. That's just my luck. I'll pull one rod cap at a time to see if I can find the guilty one. It just sucks that I'm going to end up re-torqing everything or replacing new parts. :fs1: Link to comment Share on other sites More sharing options...
Redramman Posted December 2, 2008 Share Posted December 2, 2008 Maybe thread-lock or lock-tight got spilled on a bearing or two? Link to comment Share on other sites More sharing options...
Redramman Posted December 2, 2008 Share Posted December 2, 2008 Use lock-tight when you put the bolts back in. I had a rod bolt come loose and destroy an engine once . Link to comment Share on other sites More sharing options...
HellCreek Posted December 2, 2008 Share Posted December 2, 2008 I actually had this happen to me on a 4.0 that was professionally rebuilt. First, loosen all of the rod and main cap bolts so they are not tight. Do not remove the nuts from the rod caps or the bolts from the main caps. That should allow you to turn the crankshaft. Next, verify that the main caps were installed in order from the front to the rear, using the numbers on the caps. Also, verify that they were installed in the correct direction with the arrows pointing to the front. Torque the main cap bolts to factory specifications, starting with the center cap and moving outward from there in both directions. Then check to see if you can turn the crankshaft. If you can, you have eliminated the main caps as a problem. Third, verify that the rod caps are mated with their corresponding rod and in the correct order from front to rear in the block. There should be numbers on the rods and the caps. They need to match and be next to each other when fastened together. Torque the rod cap bolts to factory specs. If everything turns, then your problem is fixed. Sometimes, as in the case of our engine, one or more of the caps, either main or rod, is torqued too high, and that pinches the corresponding journal. Following this procedure fixes that. If this does not solve your problem, someone may have installed oversize bearings on a standard crankshaft. The only fix for that is to install the correct size bearings. Tom Link to comment Share on other sites More sharing options...
ncmudslinger Posted December 2, 2008 Share Posted December 2, 2008 That's probably the problem it's been sitting up that long, you probably won't be able to break it loose with just the balancer bolt. You will have to pull the balancer and put a crank socket on it or put the flywheel on it and use a flywheel turner. Most people would think I'm crazy but if it were mine I would pick a cylinder that wasn't at top or bottom and put a short 2x4 in there and give it a wack with a dead blow. Link to comment Share on other sites More sharing options...
FxRacing282 Posted December 2, 2008 Share Posted December 2, 2008 That's probably the problem it's been sitting up that long, you probably won't be able to break it loose with just the balancer bolt. You will have to pull the balancer and put a crank socket on it or put the flywheel on it and use a flywheel turner. Most people would think I'm crazy but if it were mine I would pick a cylinder that wasn't at top or bottom and put a short 2x4 in there and give it a wack with a dead blow. may work... i was thinking the same as hell creek. but in laymen terms Link to comment Share on other sites More sharing options...
HellCreek Posted December 2, 2008 Share Posted December 2, 2008 That's probably the problem it's been sitting up that long, you probably won't be able to break it loose with just the balancer bolt. You will have to pull the balancer and put a crank socket on it or put the flywheel on it and use a flywheel turner. Most people would think I'm crazy but if it were mine I would pick a cylinder that wasn't at top or bottom and put a short 2x4 in there and give it a wack with a dead blow. may work... i was thinking the same as hell creek. but in laymen terms Sorry - Got carried away :smart: Link to comment Share on other sites More sharing options...
FxRacing282 Posted December 2, 2008 Share Posted December 2, 2008 That's probably the problem it's been sitting up that long, you probably won't be able to break it loose with just the balancer bolt. You will have to pull the balancer and put a crank socket on it or put the flywheel on it and use a flywheel turner. Most people would think I'm crazy but if it were mine I would pick a cylinder that wasn't at top or bottom and put a short 2x4 in there and give it a wack with a dead blow. may work... i was thinking the same as hell creek. but in laymen terms Sorry - Got carried away :smart: haha i know all the technical stuff and all you were saying. but it takes a little energy to think that up 1/2hour before bed Link to comment Share on other sites More sharing options...
jtdesigns Posted December 2, 2008 Share Posted December 2, 2008 Is the end of that rod chipped? Think the cam bearings are seized?? The cylinders look good.. Get to the timing chain and see if you can even nudge the cam either way... If the lossening of the main caps don't work, which I think is good advise. Link to comment Share on other sites More sharing options...
mfpdm Posted December 2, 2008 Author Share Posted December 2, 2008 IT TURNS :yes: :clapping: :jump: :banana: Thanks for all the help. :thumbsup: I started loosening main bearing caps one at a time and trying to turn it after each one. By the third one it turned. Went ahead and loosen all of them and it turned freely but I could feel a slight catch. Loosened the rod caps and the catch is gone. Torqued down the main bearing caps and it still turns but is pretty tight. How much effort should a rebuilt motor take to turn? I figure it should be alot tighter than the old 4.0 with 200k I have but this takes a good grunt. Even though I'm happy, I wish I would have done this prior to pulling the head. :doh: I guess it's good to know what it really looked like underthere. :cheers: Link to comment Share on other sites More sharing options...
carnuck Posted December 2, 2008 Share Posted December 2, 2008 I would take all the rod caps off and inspect the oil holes. If the crank was turned (machined, not rotated) then there might be burrs at the oil holes in the crank. They will scar the rod bearings (without doing a lot of damage at first other than an oil groove on a fresh motor, but left sitting it will gouge a path) Link to comment Share on other sites More sharing options...
Eagle Posted December 2, 2008 Share Posted December 2, 2008 I would take all the rod caps off and inspect the oil holes. If the crank was turned (machined, not rotated) then there might be burrs at the oil holes in the crank. They will scar the rod bearings (without doing a lot of damage at first other than an oil groove on a fresh motor, but left sitting it will gouge a path) On a related note, I was thinking before the "It turns!" report that the bearing journals might have developed a touch of surface rust that was causing them to stick to the bearings. I think I'd want to inspect them all and maybe even give each journal a quick polish with crocus cloth. Then brew up a mix of 15W50 or 20W50 motor oil mixed about 50:50 with STP, "Motor Honey," or one of the really thick viscosity index improvers, and coat the journals and bearings with that before reassembling. Link to comment Share on other sites More sharing options...
jtdesigns Posted December 2, 2008 Share Posted December 2, 2008 Sweet,,, your going to have a nice engine after its said and done,,, hell while you have it torn down swap the crank and rods for that stroker kit!!! :brows: :brows: :brows: :popcorn: Link to comment Share on other sites More sharing options...
Akula69 Posted December 2, 2008 Share Posted December 2, 2008 Sweet,,, your going to have a nice engine after its said and done,,, hell while you have it torn down swap the crank and rods for that stroker kit!!! :brows: :brows: :brows: :popcorn: x2 :agree: Link to comment Share on other sites More sharing options...
pingpong Posted December 2, 2008 Share Posted December 2, 2008 As Eagle stated you need to lube them rod and main journals before starting. I forgot who makes it (think royal purple) makes a break in oil. Or you can coat all the journals with assembly lube which should be good for start up. Might want to hit the rust on the cylinder walls with a hone..otherwise your rings might get toasted Link to comment Share on other sites More sharing options...
jaekl Posted December 2, 2008 Share Posted December 2, 2008 I think this is all kinda of silly. With all the effort you did on the rest of the truck, you were hoping this unused oldly rebuilt engine would be fine. Especially now, tear it down clean and oil all surfaces and reassemble. You could even get some plastic gage to check the clearances. You have the perfect project. A nice clean engine that just needs to be disassembed and reassembled, if you keep it stock. But yeah it's also a good time to do some mods. Link to comment Share on other sites More sharing options...
mfpdm Posted December 2, 2008 Author Share Posted December 2, 2008 I think this is all kinda of silly. With all the effort you did on the rest of the truck, you were hoping this unused oldly rebuilt engine would be fine. Especially now, tear it down clean and oil all surfaces and reassemble. You could even get some plastic gage to check the clearances. You have the perfect project. A nice clean engine that just needs to be disassembed and reassembled, if you keep it stock. But yeah it's also a good time to do some mods. :agree: I kind of get hard headed and lazy sometimes. I was just hoping to slap the sucker in but that's not going to happen. I'm stretching the length of my abilities and was a little scared to pull this thing apart. But since I have, I'm going to go ahead and break it all down, clean it up and re-assemble. Kind of have to now that I see this. Yep, that's what assemble lube looks like after it sets for 10+ years. It explains why the crank is so hard to turn. Had thought about just cleaning the cap side but I'm sure the bottom side looks just like it. Crank looks fine though. I hate that I have to buy all new seals and gaskets knowing that these were never used, but I guess it's better than having problems later. :cheers: Link to comment Share on other sites More sharing options...
aemsee Posted December 3, 2008 Share Posted December 3, 2008 I don't like the looks of that lower main bearing in the pic. Not the white stuff. There is damage on the edge where the lock is. What is that from? Link to comment Share on other sites More sharing options...
redneck23ms Posted December 3, 2008 Share Posted December 3, 2008 looks like that main cap was on backwards which is why its only worn on one side. the mains are line bored with the caps on and if you turn one backwards you will get wear on one side like that. definitely change the main bearings before putting it back together. in the pic it looks like the arrow on the center main caps are all pointing towards the rear and they should be pointing forward Link to comment Share on other sites More sharing options...
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