In the last installment I was talking about mods and repairs to get the engine ready for the swap. I forgot to show pics of the inside of the crankcase and rocker boxes. I don't know how many miles this engine had on it, but it definitely had it's oil changed at proper intervals. In fact, it was likely changed more often than needed judging by the level of cleanliness:
Of course, while I had the valve covers off I went ahead and adjusted the valves.
I also bumped the timing from 12.3° to 15°. This requires removal of the injector lines and #1 delivery valve holder from the injector pump. Removal of the timing cover isn't necessary, but it definitely made the job easier:
I won't go into details, but suffice it to say that plunger lift (indicated with the dial indicator) correlates to a certain amount of timing advance. It's a pretty simple procedure really. By advancing the timing I gained power AND economy. A win-win.
In my previous post where I showed a pic of a turbo rebuild kit there were also steel braided teflon AN hoses and a bag of fittings. The fuel, turbo oil, and IP oil feed lines were pretty beat, and stock Cummins replacements were ridiculously high priced, so I replaced them with lines I had built. This required converting the fuel and turbo oil feed fittings to AN, and even then it was still substantially cheaper than buying just the hoses from Cummins. Here's the IP fuel feed line in place, along with a new fuel filter:
I also installed the IP oil feed line (the small -3 line in the pic with the turbo parts). Oil lubrication, as opposed to fuel lubrication, is one of the reasons the P7100 pump has the reputation for being as tough as an Army boot.
Way back when, I had a V6 Camaro that I turbocharged. Before I sold that car I reverted it back to stock, and I sold off most of the parts. However, I still had the wastegate and the variable pressure regulator valve used to control it. I decided it would be cool to tie the turbo's internal wastegate shut and run the external gate. That way I could adjust the boost as needed, and the dual ported external gate would better compensate for altitude... in theory. It also would look cool, right? Right!
I picked a spot on the exhaust manifold between the two discharge plenums where I wanted to mount the wastegate and welded the mild steel flange in place with Eutectic 680 rod. I used a lot of preheat, welded 1" long stringer beads, and peened the welds with a needle scaler in order to prevent cracking. It must've worked, because it remains crack-free to this day. Next, I cut a 1-½" round hole with a hole saw. Then I used a drill to cut away the part connected to the center divider until the holesaw-cut part came free. I cleaned up the cuts a bit with a rotary file, drilled and tapped the 5/16" coarse thread holes for the wastegate mounting bolts. At that point I ended up with this:
After milling the mounting flange flat I bolted the wastegate on with stainless steel bolts:
After painting and baking the manifold and bolting it to the engine with new stainless steel bolts (anti-siezed of course) it looks even better:
While I was at it, I cleaned, painted, and baked the turbo cast iron parts since they looked like rusty pieces of you-know-what:
In this first incarnation I had decided to use an SM465 4 speed manual with 3.42 gears in the axle to eliminate the need for overdrive. The common manual trans for a Cummins swap is the NV4500, but I didn't like the 4500 for numerous reasons (just wait till later in the saga - you're gonna laugh your asses off
). The 465 has a big 1-1/2" input shaft available for it, and along with an NV4500 bellhousing and South Bend clutch it was an easy matter to get it to bolt up to the Cummins:
In that last pic you can see the turbo is assembled and mounted to the manifold. I had the turbo rotating assembly balance-checked at the turbo shop and it was perfect, so there were no show-stoppers. The last minor doo-dad I made for the turbo setup was an AN drain fitting for the block. The stock drain is simply a pressed in pipe, and I wanted to use -12 AN, so I turned down a -12AN male to male pipe, pressed a piece of 3/4" OF steel onto it, and ended up with a fitting that would press into the block and give me the -12AN drain port that I wanted:
At this point the engine was ready to mount into the truck. Things like accessory mounts were still needed, but I wanted to put the engine in the truck before I designed the mounts.
Stay tuned for the next episode appropriately titled
