Disassembly for rebuild has started.

Bottom tap them all. Run the stud to the bottom and then back it out IIRC two turns. Otherwise you might not actually be getting all the studs torqued down the same.
 
I think I'd go crazy seeing all of the studs at different installed heights.

ARP's instructions say nothing about backing them out whatsoever. Only to run them in hand tight until they bottom.

What reason do you say to back them out ~2 turns?
 
To realize the full clamping force provided by the fastener, all the threads must be clean and uniform in profile. This ensures full thread engagement.

Bottom-tap all the head-bolt bores. ;)
 
The reman'd Cummins cylinder head from Eric at Hungry Diesel finally arrived yesterday. Although it wasn't packaged the way Eric had initially packed it. The lid wasn't fastened to the crate and was only held down by two steel straps. Found the head upside down and the wrapping torn open as evidenced by the superficial rust on 5 and 6 :doh:. Why the crate wasn't built to a size only slightly larger than the head, I dunno. I sure wouldn't have built it smaller.

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.062" stainless steel wire with .012" protrusion.
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The extent of the "damage" that I can see with my naked eye is a little scuffing on #1 intake valve spring retainer.

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I'm not sure what the chances are of any stems being bent from the abuse. But, for what I've got in this motor up to this point, I'm not risking anything. I'm getting this thing to a local machine shop to have the valves pulled and checked.

I also got word from the machine shop that the shortblock is complete and ready to go. It won't be until Monday when I can go get it. I still have a few more parts to order but that will happen shortly.
 
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The head and valves checked out perfect. The machine shop I brought it to was very impressed with the work and was very thorough in their inspection. Along with checking the stems for any bends, they checked the stem lengths, spring heights and rates. Stems were all identical and all springs were very close to one another, 163-165lbs. Happy with my patience, they didn't even charge me for the 1 hour of work.

I took today off of work to pick up the shortblock and bring 'er back home.

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Mind sharing what that head cost you?

As far as bottom tapping goes, the only reason it needs to be done is so the valve covers fit on. I don't remember the exact number but something like 70 percent of the clamping force is on the first thread. Another 20 or so is on the second thread. The bottom threads of the stud are doing nothing as far as clamping force.

Again, my numbers may be off somewhat but the point is still the same.
 
I'd have to look back over the invoice for the itemized prices but the head alone from Cummins was $1400 plus a $215 core charge. After all work was done and shipping added to it, it came out to right about $3000.
 
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Cummins 12 valve head: $1,400.00
O-Ring Head: $250.00
Hamilton 165lbs. Valve Springs: $549.00
3-Angle Valve Job, Port/Polish, install Valve Springs: $750.00
Core Charge On Cummins Head: $215.00

Total: $3164.

Another heavy box showed up yesterday.

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The reason for bottoming the stud then backing it out 1-2 turns is so that if the stud turns while tightening it won't bottom out against the block. If the stud bottoms out and you keep tightening it then if could give you and false clamping force on the head or the stud can break.
 
Bottom tapping holes on a motor your rebuilding shouldn't be a questions of do I need to do it. It's the same as cleaning the oil galley. Should be done on all holes. Why not clean the crap falls in them and clean the threads.
 
Little progress made this weekend. My family decided to surprise me with a birthday party yesterday. Picked up a bottoming tap on Friday. Earlier this evening, I put the billet freeze plugs in.

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SKYNYRD said:
The reason for bottoming the stud then backing it out 1-2 turns is so that if the stud turns while tightening it won't bottom out against the block. If the stud bottoms out and you keep tightening it then if could give you and false clamping force on the head or the stud can break.
Click to expand...

I've installed quite a few sets of head studs in the past year, and I've never had a stud that was "properly" backed off a turn or so, that didn't immediately turn back in and bottom out in the block by the time torque on the nut above hit 75 ft lbs or so. I now just lightly snug all the studs to about 10 ft lbs or so and usually have very little stud movement during the torque process.

If you think about it, the top of the stud has the fine threads that will develop much more clamping force from a given torque than the bottom coarse threads. I also think a stud bottoming out on the threads that aren't fully cut puts less thread pulling force on the block threads than a fully tapped stud hole that bottoms out on the bottom of the block.

You don't commonly hear about thread failures so it probably doesn't matter how the install is performed as far as block thread failure.
 
I checked the torque on all of the mains and rod cap bolts. Installed the oil sump pick up tube and then put the oil pan on. Once all the bolts were torqued, I sprayed it and the bolt heads with some gloss black. Next plan is to JB Weld the perimeter of all of the expansion plugs.

My original oil pump part number was superceded by the later pump #4939587. Running with it.

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New block heater.

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Keating rear plate.

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Bottom tapping the threads in the block was easier than I anticipated.

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Forgot to mention that piston protrusion came to .024-.025" and valve recession is at least .045". Ryan at Hamilton says that a standard head gasket will be fine to run with the 182-214 cam and those dimensions. In fact, those numbers are right at the maximum and minimum for their cams to be 100% bolt-in for a 12 and early 24 valve (VP) engines.
 
Primed and painted the new head today with VHT. Rated for up to 2000 degrees.

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The cam gear was treated to a retainer from Hamilton.

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Applied JB Weld to the remaining expansion plugs; oil rifle and coolant plugs in the tappet valley, oil rifle and cam plug at the rear of the block.

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I also bought new rocker levers, thrust washers and retaining rings. New levers weren't necessary as the existing levers were fine but a new set wasn't that expensive. However, Cummins only had half of the retaining rings on hand so I'll have to wait until next week to assemble the remaining 3. All of the rocker shafts maintained the maximum specified diameter of .747".

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What are thoughts on Victor Reinz gaskets? Specifically, head gaskets. The rebuild kit came with a VR upper engine set. I'm all about Genuine Cummins for anything to do with a Cummins motor.
 
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