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Why did this overhaul fail?????


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Didn't want to get into a huge debate so hesitated to ask this question. New out of frame OH on a 466 engine. Everything checked out perfect, ran it in the shop before we put it in the tractor. Everything was new except the turbo, the oil cooler and the crank. The crank checked perfect. Machined and balanced rods and full head rebuild. We have done many of these and never had an issue until now. Less than 10 hours and it spun a rod bearing. We very meticulously disassemble the entire thing. Can not find any issues. Oil galleys are all clear as well. Oil pressure was 60 at idle and 75 at high idle on two manual gauges, one on injection pump line and one on right rear of block. The main bearings look like we just put them as they should. The rod bearings are another story. Four of them look like they should one set looks like 8000 hours and of course one set spun. Number one looks like 8000 hours and number five spun. We have a diagnoses, but wonder what you think happened. 

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Do the mains have hones in them that line up with the crank oil galley holes? More than 1/4 of main saddle oil galley hole covered? Only place the rod gets oil from is the crank galley bores. What was your clearance on the rods? You say that the galleys were clean. I assume you mean crank galleys too?

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Agree on the question about main bearings oiling holes aligning with the block galley holes.

Also - were the connecting rods reconditioned and the big end re-sized?

I never put an engine together without checking every bearing's clearance with plastigauge, was that done and what were the clearances?

One other question - why was the engine rebuilt?

Was it just worn out or was there a failure?

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X2 on plasti gauge. Kind of late now but can you be certain bearing clearances were correct? Was this an aftermarket kit with a questionable reputation or a high quality aftermarket/dealer kit? 

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this is way beyond my wheelhouse, all i have is empathy to offer for the most part, i would be overwhelmed, frustrated, confused too - sounds like the guys have some good info to offer you. From my small engines class this doesnt make sense outside of lubrication - my logical brain would eliminate some kind of alignment with the crank/bore since the mains are good and the engine lasted a long time before the rebuild presumably.

Maybe the rods were not right causing some kind of issue on those bearings? Casting issue?  Something happened like hydro lock that compromised them before you tore it down from someone cranking on it ? I dont even know if that is possible on an engine this big but just a thot I had because of a small diesel ford that hydrolocked from water and bent rods in it trying to start it. 5y/o sprayed water up exhaust pipe and dad didnt know. 

 

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To answer some of the questions, as I stated in the original post, the rods were balanced and sized, all the holes line up properly in the mains for oil, the crank oil galleys are clear, the locations of the failed rods was given in the first post. Everything was in specs and checked. Rebuild grease was used and we pressure inject new engine oil after a rebuild. We ordered a Federal Mogul OH kit. However when it came it did not have anything labeled as such. All components say Reliance. I know a lot of people are bashing Reliance and didn't want to go there right off the bat. However, it has bean concluded by us and others that we have asked and showed the engine and parts to that is simply poor quality bearings. So we wrecked the crank and did a complete OH and now are doing it again. Really wanted to see if there was any way we missed something, so I asked here. You all have good insight. Frustrating that it failed, we all make mistakes and I was sure we missed something, allowing failure. No such evidence anywhere. Trying to get good parts is almost impossible anymore. Thanks for the comments.

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14 hours ago, INTERNATIONAL 1466 said:

Everything was new except the turbo, the oil cooler and the crank

If you had a catastrophic failure with metal entering the oil and reused that oil cooler right there is your culprit.  

Its impossible to get all the shrapnel out of any oil cooler

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Call the boys at restoration tractor sales in PA, they got the REAL DEAL engine kits custom made for them super good guy's to deal with

I wouldn't use a Reliance parts box to put my trash in THEY SU@K

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1 hour ago, INTERNATIONAL 1466 said:

To answer some of the questions, as I stated in the original post, the rods were balanced and sized, all the holes line up properly in the mains for oil, the crank oil galleys are clear, the locations of the failed rods was given in the first post. Everything was in specs and checked. Rebuild grease was used and we pressure inject new engine oil after a rebuild. We ordered a Federal Mogul OH kit. However when it came it did not have anything labeled as such. All components say Reliance. I know a lot of people are bashing Reliance and didn't want to go there right off the bat. However, it has bean concluded by us and others that we have asked and showed the engine and parts to that is simply poor quality bearings. So we wrecked the crank and did a complete OH and now are doing it again. Really wanted to see if there was any way we missed something, so I asked here. You all have good insight. Frustrating that it failed, we all make mistakes and I was sure we missed something, allowing failure. No such evidence anywhere. Trying to get good parts is almost impossible anymore. Thanks for the comments.

You said you have done many of these, is this your first use of reliance bearings?  From what I’ve read I really don’t think you did anything wrong. Especially since you have good bearings next to roasted ones. I’m wrestling with the same scenario right now. Did 3 AC 7030s with 100% reliance parts. 2 of them have been running flawlessly for about 5 years. The one I have pictured in another post is on its 3rd round of melted pistons. All were auction tractors, but this current one is the only one where we haven’t touched the fuel system. Starts an runs beautifully, no smoke, but in approximately 25 hours owner is calling me with the same story.... 1 dead cylinder, heavy knock. Talked to AC guys all over Ohio, they all ask the same question: what condition are the injectors in? Well waiting to hear from fuel guy as we speak , so the story isn’t solved yet. I can buy injectors washing down the cylinders to a certain extent, but how the entire skirt get wasted with all that oil being thrown up from the crank?? Something we have in common, is my rod bearings are starting to look stressed, but only in the bad cylinders. Sorry for high jacking your post, but I think there are some similarities here. I’m not too happy with Reliance myself, but I’m having a hard time believing your failure is the fault of the parts themselves.

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95852AD7-8495-4B71-8334-095B261B7CE9.jpeg

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If this engine is in a tractor where the front motor mounts with 2 bolts on each side, make sure the correct gasket is used between the front steel plate, the front cover, and the engine block. If the gasket is used for the front cover without the side mounts the front cover will warp when torqued down which will also warp the oil pump enough to allow it to suck air on when the oil gets hot. I saw an engine fail that way twice before the problem was found.

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39 minutes ago, Owen Aaland said:

If this engine is in a tractor where the front motor mounts with 2 bolts on each side, make sure the correct gasket is used between the front steel plate, the front cover, and the engine block. If the gasket is used for the front cover without the side mounts the front cover will warp when torqued down which will also warp the oil pump enough to allow it to suck air on when the oil gets hot. I saw an engine fail that way twice before the problem was found.

Have heard that too, the correct gasket was installed.

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2 hours ago, Binderoid said:

You said you have done many of these, is this your first use of reliance bearings?  From what I’ve read I really don’t think you did anything wrong. Especially since you have good bearings next to roasted ones. I’m wrestling with the same scenario right now. Did 3 AC 7030s with 100% reliance parts. 2 of them have been running flawlessly for about 5 years. The one I have pictured in another post is on its 3rd round of melted pistons. All were auction tractors, but this current one is the only one where we haven’t touched the fuel system. Starts an runs beautifully, no smoke, but in approximately 25 hours owner is calling me with the same story.... 1 dead cylinder, heavy knock. Talked to AC guys all over Ohio, they all ask the same question: what condition are the injectors in? Well waiting to hear from fuel guy as we speak , so the story isn’t solved yet. I can buy injectors washing down the cylinders to a certain extent, but how the entire skirt get wasted with all that oil being thrown up from the crank?? Something we have in common, is my rod bearings are starting to look stressed, but only in the bad cylinders. Sorry for high jacking your post, but I think there are some similarities here. I’m not too happy with Reliance myself, but I’m having a hard time believing your failure is the fault of the parts themselves.

931C23AD-3917-4A6B-98A9-C5426F36ED52.jpeg

95852AD7-8495-4B71-8334-095B261B7CE9.jpeg

Not to hijack either but thats a clearance issue either due to overheating of the piston, or not enough skirt clearance in assembly.  Im not an AC guy but first place to look is cooling jets, and then for overfueling.  

If i get a rebuild kit that doesnt have preassembled cylinder packs i always check skirt clearance.  Get the spec from whoever made the pistons too as metallurgy and expansion charecteristics have changed in the 40 years since OEM manuals were printed.  

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5 hours ago, m.c.farmerboy said:

Call the boys at restoration tractor sales in PA, they got the REAL DEAL engine kits custom made for them super good guy's to deal with

I wouldn't use a Reliance parts box to put my trash in THEY SU@K

I agree with all of this

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That Sux

Even with plasti gage  you may not catch a roundness of the bearing issue unless you measure the clearance in several locations

Or you would have to check the roundness installed in the rod   

There is so much low quality stuff out there its hard not to get burned once in a while  

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Obviously this is not your first rodeo, and you may take this as a stupid question, but it seems rather strange that the rods are having that much problem and not the mains. It's not a situation where the rod or bearing is riding against the radius on the journal?

Other than that, it almost sounds like the babbitt is peeling away from the copper. Can you look at a bearing under a microscope to see what it looks like?

I suppose the babbitt thickness buildup on the bearing could very, but pretty slim chance of checking a number of them and finding the good spot all the time.

You say they machined the rods. I assume they machined the split and rebored the big end? May be worth putting the caps on the rods and torque them down, then check with a bore gage. I am sure your shop does good work, but, process of elimination.

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21 minutes ago, Mighty1206 said:

Not saying this is your problem but the only time I've seen something like what you're describing was when someone mixed 2 rod caps up. 

That is the first question my machinest asked. I checked that first, didn't happen. I was almost hoping I had, then the problem would have been obvious. 

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