More progress
Here's what I did today:
I put the main bearings in place, torqued the caps back down, and measured the bearing ID's with my trusty dial bore. The spec for the 6.2 and 6.5 is .0018" to .0033" clearance for 1-4 and about a half-thou more for #5 (.0022 to .0038 IIRC). Mine measured .003-.0031 for #1-3, .0027 for #4, and .0035 for #5. These are all within spec. I could have got a set of .001" undersized bearings and used a .001 undersized upper with a standard lower to reduce the clearance by .0005" on 1-3 and 5, but I don't need to since they ARE in spec and I am using a high volume 97-up oil pump. Besides, I didn't feel like spending $60 on a set of main bearings that would effectively get thrown away (half the spandard set and half the .001 under set wouldn't be used), and if you have the oil volume then bearings a bit on the high (loose) side are preferable.
Once I verified the clearances are OK I moved on to the crank. It was basically ready, except I wanted to polish up the rod journals a bit. They were a bit hazy from sitting for such a long time. I used the method outlined in the
Chevrolet Power Manual, where you cut a piece of fine grit sandpaper (1200 grit is what I used) to fit the width of the journal, wrap it around tight, and use a piece of masking tape to hold the overlapped edge. Then you wrap a thong (like a piece of thin rope, not an undergarment
) made of leather (or in my case vinyl tubing) once around it and work it back and forth rapidly about 20 times. It takes all of a minute to do one journal and it makes it look like a mirror. The mains already got hit with the polishing belt by the machinist after he balanced the crank, so they didn't need to be messed with. I cleaned the crank with brakleen and it was good to go.
I also polished the journals on the cam with 1200 grit. One lobe had a ding on the outer edge where the roller would probably never touch it, but I removed it with a fine grinding stone. I also used 400 grit on the oil pump drive gear teeth to smooth away the wear marks from it's previous life. It can make new ones in this motor
.
All that was left was to use plenty of assembly lube (a moly paste lube in my case - I wanted something thick and clingy that will stay put over time since it will be a few more months before the engine fires) on the cam and plug it in. Then I lubed up the main bearings and got ready to install the upper main seal half when I discovered that my cheeze-whiz-can of Ultra Black was MIA
I ended up making a trip down to Autozone, and all they had were squeeze tubes of UB
. Anyway, I finally got back to it, I use a small amount of UB in the seal groove in the block and cap, and a VERY thin, almost nonexistant amoint on the parting faces of the seal. The seal gets installed offset in order to align the rear cap:
You notice in that pic you can't see the silicone on the parting face of the seal. It is THIN, thin enough that it won't ooze out when you tighten the cap, but enough to prevent oil from working it's way out between the surfaces. If a tiny amount should ooze out the oil that I put on the crank's seal surface will prevent it from sticking. I have done this numerous times and haven't had a seal leak yet. Finally, I used a really thin, narrow bead of UB from the seal to the cap register on each side. The book says to use "anaerobic sealant part # xxxxx, but I have found good ole UB works fine. Finally, I dropped the crank in place, installed the caps, tapped 'em in place with a plastic-faced hammer, tapped the crank forward and back with said hammer to align the thrust bearings, and torqued em up.
Despite using studs in place of the stock bolts and having a girdle in place the main bores on my block didn't need to be align bored, but I had to follow a strict torqueing sequence in order to keep the bores round as they are tightened. Using ARP moly lube I torqued the inner bolts starting with cap 1 and going to 5 in three stages until I finished at 90 ft/lbs. Then the girdles were put in place and the outers torqued in the same sequence to 80 ft/lbs. Finally the crank is in it's permanent home. A quick check showed .005-.006" end play, which is in spec. Here's the pics:
Both the cam and crank spin freely, although the assembly paste makes it feel like you are spinning 'em in molasses. Next step is to make sure the rings, which are preassembled on the pistons by Mahle (and you really don't want to try to take them off) are gapped properly, install the pistons on the rods, and stuff 'em in the holes.
Stay tuned
and 
to get it to fit. From the looks of it I can probably just grind a bit more off of the corners of the girdle and it should drop in. Then I can fit new metal on the pan to clear the studs.
, half circle) which drives the IP sheared off making it run like poop. The owner gave up and began parting the truck out and didn't find the sheared key until after he pulled the engine and sold the turbo & IP. From everything I see the rebuild is good and I am taking the chance it is. I've pulled the oil pan & the heads but don't want to go any further so that limits my options.
