A little 4.7 for the DD.

[cal]

A while back my radiator on my DD failed and blew all of the coolant into my airbox. Managed to suck it into the engine, and then drive further than strictly speaking was a good idea before stopping. (the motor oil sounded like a deep fryer..).

I was talking to Russ about rebuilding the motor out of 4643 for this car, but somewhere we got the idea to turn up the heat a little. I'm just cut and pasting the posts from Naxja over here, but figured I'd share. A lot of this stuff won't be very groundbreaking for this crowd, but it was written with a different group in mind.

Originally I was going to build this myself with Russ parts, but somehow he ended up doing most of the work, which I have no problem with.

[cal]

Started off with a 99-04 NVH block.



Russ punched it out to .060 over and chopped the top off of the deck, and set me to washing it.

Started off with a large assortment of brushes.



Lots of scrubbing the outside.



Lots of scrubbing the inside.




And into every oil passage.







And a good hot water rinse.



I didn't take any pictures, but after this I wiped every machine surface down with Marvel Mystery Oil to prevent flash rust, and then painted it.



And then I got criticized for not painting the back red. I don't know why red, but it got done.

[cal]

And then into the shop for some work.

Cam bearings.









Russ marks the bearings with an "up" line so the oil hole stays lined up.




Even though he carefully aligned them, he went back and checked to make sure the holes passed through correctly for every oil hole.

[cal]

Next Russ started prepping the rods and pistons.


Russ's Scat rods. They are forged steel H beam and bushed for floating pins (I didn't think to ask what steel, but he may pipe up in here).




The caps are doweled for additional strength.



Next to a stock rod you'll notice they are far more substantial, and you will also notice there are no balancing pads - so they clear the girdle in a late model block without grinding. I managed to not get a picture of it, but they also have ARP bolts.



So he installs the bearings, torques the bolts. He measures the corresponding rod journal on the crank, and zero's his dial bore indicator to that exact size, and then uses it to check the rod bearing clearance on a per rod basis.





This rod has roughly 2.5 thousands bearing clearance.



Number the rod (and cap) so you are sure to put it in the right place later, and then also label which side points forward.

[cal]

Russ also has his own pistons made. In fact I think a bunch of you are familiar with his pistons.

But you aren't familiar with *these* pistons.

Edelbrock a couple of years ago released a new aluminium head for the 4.0. They missed a lot of opportunities as far as upgrades goes, but the one thing they got right was reengineering the combustion chamber instead of re-using the same AMC chamber from 1941 (1941! jeep used it until 2006). The combustion chamber is a bit smaller both in CC (55) and overall footprint, giving you a better quench zone.

Russ had new custom pistons made to take advantage of that.



You'll notice unlike any other 4.0 piston (at least that I have seen) to date, these are not all the same. They are asymmetric to match the intake/exhaust orientation of their cylinder. They are forged high silica aluminum (4041? he told me and i don't remember the exact compound). He feels its the best compromise between strength and user friendliness. My particular pistons are a 3.935 bore, 1.385 compressed height and a 14cc dish.




Compare to his standard iron head pistons.



And to really show what we mean.




Back to building.

Once we establish which pistons belong to which holes, we need to label 'forward' so we don't put them on backward.



Toss the rod in the rod vice, slide the piston on, slide the pin in, drop in 2 C clips, and then re-mark 'forward'.

[cal]

Once the pistons are hung, its time to toss the crank bearings in, and torque the caps down.



Measure each main journal.



Zero out the bore indicator.







Measure the corresponding bearing.



And repeat the entire process over and over again, removing caps as we go.

[cal]

Back to the pistons, its time to install new moly rings.

Russ made a point of going in and filing the ends of every ring back just a little to make sure they aren't going to scratch the cylinder wall.





He installs the rings not only with the gap 180* out from each other, but also makes a point to put them on the sides of the piston, where there is no cylinder wear from the skirts and its not a thrust wall.

[cal]

Russ keeps an old cam around just for testing cam bearing installs. Once the bearings are in, he slides his cam in and spins it to make sure there is no binding and it has the anticipated amount of drag.



Apparently its pretty common in the graybeard builder crowds to actually grind all of the lobes off of a cam to keep around just for this job, but he feels its unnecessary.

[cal]

And now onto the crank. Drop the crank in, with the first, last, and thrust bearing, and spin to to check for drag and make sure there is proper fore/aft movement in the thrust bearing.



No gauge for this one, he does it by feel, with a screwdriver he apparently only uses for this job.





When I asked about the spec, "it just needs to move a little". It does just move a little.

[cal]

Now to liberally lube up all of the rod bearings (everything else got lubed up, but usually I was doing it so i didn't stop to take photos).





One last marvel mystery oil of the cylinder walls before dropping the pistons in.



Piston into the ring compressor.





Making sure the compressor is seated and square




And gently tap it home.





Now doing number 6 since they run in sync.



You'll notice that the rods had no studs, so there was no reason to cover them with a sleeve or hose.

[cal]

Roll it over and install the caps. Remember they are numbered and have forward marked, so its pretty easy to not fail here.



Nice bolts. Lubed, like everything else.



One of the bearings moved a little. Russ just pushed it back in place with a screwdriver.

[cal]

Pistons are a little out of the hole. We'll get to do some math on that shortly.



Russ taps the pistons on all 4 corners to square it up in the bore (I was shocked how much they move).



And then measures how far out of the hole it is at all 4 corners, and marks them.





They average about 12.5 thousands above deck. We're reusing a crank that has been ground a couple of times, and there was a shocking variance from cylinder to cylinder (.010 to .0165 out of the hole). Russ said it's kind of on the extreme end, but I already own this crank so we're moving forward with it.

[cal]

Next Russ dropped the oil pump on there. We went with a high volume Melling.

In my application we don't need to clearance the pump, but for most oil pans you do have to, so he did it to document it in this thread.





This mark is where you hit the pan. Clearancing involves sanding the corner of the pump and pounding the baffle in the pan with a balpean until the pump clears.





45 seconds on the belt sander.



Russ wanted me to point out that there is a machine ledge on the surface the oil pump mounts to. On most blocks there is miles of clearance, but every now and then the aftermarket pumps do hit the ledge and do not sit flush, in which case you need to grind the block a little bit.

You can see the ledge here. Loads of clearance.

[cal]

And that's about as far as we've gotten to this point. My cam is sitting on a pallet on a truck in route to Russ, due to come in next week. Once that arrives we'll pick up here and keep going.

[SkylinesSuck]

I love reading this