Short Block Assembly
Step 1: Piston cooling nozzles
The IE pistons have a relatively generous relief notch cut into the skirt, so you don't need to be pinpoint accurate, but you do need to be in the ballpark to make sure you're near the center of the notch and have adequate rod clearance.
The #4 cylinder nozzle has no access with the crank installed, and the crank does slightly limit access to #1-3. It's best to get them in where you expect them to need to be, and torqued to 20ft lbs (27nm) with a T40. See below.
Step 2: Main Bearings and Thrust Bearing
First thing to note is there is no aftermarket main bearing for these engines that i am aware of. There are some companies (King, Bar-Tek/ACL) that catalog them, but King has never actually produced them and the ACL ones do not fit. I bought them, they're not even close.
You have to order OEM main bearings. There is a bit of a process for this. The factory measures the clearances and assigns codes to each engine. I would take good pics of these codes for you, but after the block and crank were hot tanked the laser etched codes are now gone. Unfortunately i dont have a pic of the crank code, which is located on the back of the crankshaft and is visible near the rear main seal. The crank code corresponds to the lower shells. I do have a picture from teardown of the code on the block, which corresponds to the upper bearing shells. RRGRR was my code:
From there, you reference page 64 of the engine manual to find your colors. Do not expect a dealership to have a clue how to do this process BTW.
So, in my case, to achieve factory clearances i would order 4 Red / 1 Yellow upper main bearing shells. That said, i wanted to loosen up the clearances slightly because it's a severe use application, so additional oil cushion and the freedom to run a bit more viscosity are very welcome. I chose to order 4 Yellow / 1 Blue, therefore going 1 size thinner on all shells. I did the same for the lower shells, followed the factory code but 1 size thinner.
In keeping with the title of the thread, this build is DIY-ish. I had the machine shop do all bearing clearances. My guesstimate resulted in a 0.0015" clearance on 4 of the five main journals, with the exception being the center journal which came back at .0010". Instead of messing with ordering more bearings to try to get the perfect combo for the problem journal, i simply had them polish a half thousandth off the crankshaft to bring that journal in line with the others.
At this point you install and lubricate the main bearings with assembly lube. Also install the thrust bearings with a coating of assembly lube. They go on each side of the center main bearing, and the crank itself and the main cap will wedge them in place so they cannot move. Red arrows point to the thrust bearings. When these fail, crankwalk occurs.
Drop the crankshaft in very gentle like a little baby, and put the caps in place.
I used OEM main bolts (M12 Triple Square), largely because i didn't want clearance issues between ARP main studs and the OEM oil control equptment. Typically these bolts go in wet, so i dipped them in engine oil prior to install. My recommendation is to follow the TQ sequence below, but only torque to 48ft-lbs (65nm). DO NOT yield the bolts an additional 90 degrees. Remember those oil squirters from the first step? You can't confirm if they clear until the pistons and rods are in. If they don't clear, the crank has to come out. If you yield the bolts, they're junk.
After the crank is in give it a light spin to verify all is smooth.
Here is the TQ Sequence for the crank, page 63:
Step 3: Pistons and Rods
A block should always be bored to the pistons, you never bore a block and try to spec a piston to fit. After conversation with Mahle, i went slightly larger than IEs recommendation (.0013-.0017) and settled on a .0020" piston to wall clearance. The block was bored accordingly, and the rotating assembly was balanced.
Again with the DIY-ish, i did not bother grinding the rings myself. We used a .023" end gap on the compression rings (both upper and middle), and i had the machine shop file fit those. If you've ever tried to do it on a cheap grinder, its a real nightmare and i'd rather pay the extra $50 and have them ready to go.
You can install 1&4 and 2&3 in pairs, so the crank journals are out of the way. Pistons get a dunk in engine oil before being sent home. I bought a Wiseco 83mm ring compressor, and i will never attempt to use one of those oil filter wrench style ones ever again. Trust me, this is the way to go. The piston should go smoothly into the compressor, and if it doesn't something is wrong. It will not require anything more than little love tap with the butt of a hammer to put them in the block. Push the piston far enough into the compressor that the skirt is sticking through so you do not have to guess where the bore is.
I used Calico coated road bearings with a .0015" clearance. You can either install the upper shell onto the rod and be very careful with your tapping into the block, or install them without the rod bearing and put them in through the bottom.
At this point, only snug the rod bolts. Rotate the crank and check for oil squirter or "Piston Cooling Nozzle" clearance for both the rod and piston, red arrow:
IE rods come with ARP 2000 bolts. These are 7/16" 12 point, and need to either be torqued to .006" stretch, or torqued 3x to 50ft-lbs to season the threads. ARP Moly lube is included, and it is critical to use it, because it will dramatically change the TQ values compared to something like motor oil.
Once the clearances for the squirters are confirmed, follow the previous sequence and yield the main bolts an additional 90 degrees. After that, the rods can get torqued with the 50ft-lb 3x procedure (tq to 50, loosen, repeat 3x).
There are 6 bolts that go into the 3 main caps. I used a Q-tip and acetone to take the paint off the block in this area so it wouldn't interfere with the TQ spec. These are M10 triple squares and torque to 15 ft lbs (20nm) and then yield and additional 90 degrees.
The short block is assembled: