Disassembly for rebuild has started.

Pulled the motor again today. Block was cracked behind the bolt bore for the head stud. I don't think it was that way from the machine shop. The only way I can think of this happening is from the 1 hot retorque I did. One of the front bolt bores also cracked into the water jacket but didn't go external like the rear.

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A buddy of mine here has a shortblock from a 93 he's selling to me for $100. Stay tuned.
 
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I see them now. Ugh!! I have heard that the later model 12 valve block is stronger and the STORM blocks (01-02) are the strongest.

I've also heard of a 12valve IH block.
 
What are some thoughts about boring #6 .001" over with the lack of coolant flow issue these engines have? This article is one I read last year after the initial rebuild was already complete so it was too late. But this time I have a chance to do something about it. Is it very critical given the performance level of my particular engine?

How to give a Cummins 5.9L 12 valve a second life

I briefly spoke with the machine shop about it and was told that the Powerstrokes and Duramax's have similar issues and, as well, have the rear cylinders bored a hair over to compensate. I also want to ask about using a torque plate when boring the cylinders. This isn't a high performance engine but I like having things done right, if I can help it.
 
jimbo486 said:
What are some thoughts about boring #6 .001" over with the lack of coolant flow issue these engines have? This article is one I read last year after the initial rebuild was already complete so it was too late. But this time I have a chance to do something about it. Is it very critical given the performance level of my particular engine?

How to give a Cummins 5.9L 12 valve a second life

I briefly spoke with the machine shop about it and was told that the Powerstrokes and Duramax's have similar issues and, as well, have the rear cylinders bored a hair over to compensate. I also want to ask about using a torque plate when boring the cylinders. This isn't a high performance engine but I like having things done right, if I can help it.
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Two things I have learned about Cumminses and pistons.

1. Always use Cummins pistons. I am well aware that Mahle supposedly make the pistons for Cummins. This being said, I have seen more Mahle pistons scored than those sourced from Cummins.

2. This is just me personally, but the last couple Cumminses that I have put together I have had the machine shop bore to the point where we have an .008" cylinder gap. My 4BT that scored more than once is currently running .010" piston to cylinder wall clearance.

I have seen no negative affects of the larger clearances. No oil consumption no noticeable extra rattle, and no scored pistons.
 
I spoke with the machine shop earlier. They had called Mahle and brought it up. Mahle is aware of this but suggested boring a little less than .001", maybe half of that.

The core block has already been machined and is ready for assembly so it's not too late if I want to request to open it a bit more.
 
jimbo486 said:
I spoke with the machine shop earlier. They had called Mahle and brought it up. Mahle is aware of this but suggested boring a little less than .001", maybe half of that.

The core block has already been machined and is ready for assembly so it's not too late if I want to request to open it a bit more.
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What is your overall piston to cylinder wall clearance going to be?
 
Red Sleeper said:
What is your overall piston to cylinder wall clearance going to be?
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The shop tells me that cylinders 1-5 should be about .00425" while #6 should come out to a little over .005".

I was told they spoke with Mahle who is aware of this. Mahle suggested over boring by .0005-.001". The shop split the difference and bored .00075" over.

Sent from my SAMSUNG-SM-N920A using Tapatalk
 
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First thing I noticed when looking over the shortblock. I was clear when I told the shop that the dowel pin would need to come out of my original block to be used in the replacement (since its dowel pin had fallen out). Apparently, the guy working on it didn't pay attention to that or didn't get the message. Nor did he pay attention to the the orientation of the tab.

With the case being off a couple of degrees, the timing pin didn't align with the cam gear. I found exact TDC with a method very similar to the book. The pin housing mounting holes needed to be opened up some in order to realign the housing and pin.

With the luck I've had, I'm been debating with myself whether or not to take it back to the shop to have them correct this. Although, it doesn't appear that there will be any issues. At the very least, I'll make the shop aware and discuss a deal in regards to repairs should anything related happen.

Other than that, I've got the oil cooler, filter head, tappet valley expansion plugs, billet freeze plugs and billet tappet cover installed. Once again, used JB Weld ClearWeld epoxy on all of the expansion plugs in the block.
 
You're seeing correctly. The dowel pin was not installed in the block prior to mounting the timing case. The alignment is off a little bit which warranted having to find exact TDC #1 in order to realign the timing pin that engages the cam gear.
 
I'd be concerned about gear-tooth engagement.

Isn't there a second locating-pin toward the bottom of the gear-case?
 
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BC847 said:
I'd be concerned about gear-tooth engagement.

Isn't there a second locating-pin toward the bottom of the gear-case?
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There is a second pin in the block below the oil pump. I'm assuming it's in place but this one being missed makes me wonder. I'll be sure to put eyes on it. Gear engagement was a concern I had as well. I don't know how much of an affect this could have on the other gear-driven components and if I let it go, it could become a larger inconvenience later on. I wondered if there would be any unnecessary axial load on the injection pump or vacuum pump gears/shafts, improper gear lash or premature wear on all associated gears.

Ram12vcummins said:
Is your pan gasket gone seal? Pump gear gonna mesh properly? That looks like a lot to be off.
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Good point. I hadn't thought about the pan gasket.

With the luck I've had, I'm not gonna take the chance. I spoke to the shop this morning and I could hear the disappointment in the owner's voice. Since the replacement block had lost the dowel pin, it was discussed with the owner when the blocks were dropped off. He recalls the conversation him and I had about it. It was written on the paperwork to remove the dowel pin from my existing block and install it in the replacement. Lost in translation or lack of thorough reading of the paperwork for the assembler.

Anyhow, the shop has taken full responsibility as I trusted they would. A new oil pan and timing case gaskets are being ordered today. The engine is going back to the shop on Thursday.

I wish I had the machinery and tools to do this work myself. As is said, if you want something done right.... :rolleyes:
 
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