I bought an 86 6.9L diesel and I'm just wondering where would one want to buy a rebuild kit from? Also i was reading a while back about the pistons and they have to be (something can't remember the name) and not cast what type of pistons do you want to put in, and where would one buy a complete overhaul kit?

 

Caterpillar,
I got your PM and just have not had time to answer it.

First find a good machine shop and have the engine block and heads hot tanked.
Mic and magnaflux everything so you know what you have to work with.
Do a minimum bore on the block, pistons are available in 20, 30 and 40 over from most places.

I bought most of my parts through the machine shop I used, the prices were very competative with everywhere else I checked.
Also since the machine shop knows exactly what oversized or under sized parts you need, it will be faster for them to order the parts when they check everything out and get it cleaned up.
Have them balance the rotating assembly in the engine for 4000 RPM or higher.
Makes for a much smoother engine.

Bearings, rings, cam, lifters and pistons were from Sealed Power.
All the gaskets and seals were from Fel-Pro.
Use 7.3 exhaust valves, they are inconel and much better.

For pistons your choice is forged or cast.
The cast pistons are a hypereutectic alloy which has a higher melting temp than the forged pistons do.
They are also more brittle than the forged pistons are.
I was planning mid twentys for boost when I built my engine, and given the higher melting temp as well as the cost was about 1/2 what forged pistons cost I used the cast hypereutectic pistons.

Since you are planning a pulling engine which will only see high EGT for about 300 feet hopefully, they may not be the best choice for you.
When I load up a piece of machinery, I may be pushing 1100 degrees or more for miles.
Remember EGT over 1250 is not going to cause sudden catastrophic engine failure, but the pistons will start to be damaged.
The damage will add up untill you do have piston failure at some point though.

For an out and out pulling machine, you are probably going to wind up running much higher boost than I do, twin turbos and other custom parts such as that.
Ken at DPS can steer you in the right direction, I am going to say forged pistons with ceramic coating will probably be a better choice for that application.
But then you are looking at about 90 dollars per piston.

Also to run boost over 30 PSI, you will need to mill the pistons down to lower the stock compression.
80 thousandths off the piston crown will drop the compression ratio to 18 to 1 which is what the Power Strokes run.
I went 40 thousandths which dropped my compression ratio to 20.25 to 1.

Bad thing about that is it is harder to start a cold engine with lower compression.
As a test this winter I did start mine with only glow plugs at 7 below, but that was about all a set of new 1000 CCA batteries wanted. It did stall several times after it started until I learned when to hit the manual glow plugs again to keep it running.
After the engine was running for a minute or so, everything was back to normal because it was starting to build enough heat in the engine to fire by it's self.

Head studs, are a must, I bought mine from Summit Racing.
Made by ARP and have the same specs as Kens for 100 dollars less.
Be carefull though, they do show several different yeild strengths, mine were 220,000 pounds.
Be careful to follow the instructions, moly assembly lube applied sparingly,
Torque the heads down in steps and remove them at least 5 times before you do the final assembly.
This lets the nuts wear into the studs for a more even torque reading across the head.

I was tired after just installing and torquing down the heads.
Final step was 105 foot pounds.
Also as a side note, wipe the heads and gaskets down with acetone before you drop the head gaskets onto the block and the heads onto the gaskets.
Make sure you do not use enough assembly lube on the studs that it contaminates the head gasket surfaces.

I also found out that the stock intake manifold and exhaust manifold gaskets can not stand boost over about 22 PSI.
So what I did to take care of that was use grade 8 bolts to fasten both on the heads.
The gaskets for both were coated with three coats of Permatex Copper spray gasket maker on both sides, the mating surfaces for them were also sprayed with two coats and allowed to dry completely before assembly.
The bolts I used were longer than the stock bolts, so I shimmed them up with grade 8 washers so they were just short of bottoming out in the hole when they were at double the stock torque reading.
All the cross over pipe and Y pipe to manifold connections have NAPA 31311 exhaust gaskets installed between the parts.
The center hole is just right, but the bolt holes are about 3/8" to close together.
A little work with a drill press moved the holes out enough to make them work.
I also used the copper gasket maker on all of those before I assembled them, same treatment as the intake and exhaust gaskets.

I wrapped every exhaust pipe before the turbo with a double layer of header wrap that I could, the first layer was soaked with high heat ceramic paint a couple times before I installed the next layer which I also soaked with high heat paint.

That keeps the heat in the exhaust, spins the turbo sooner and faster.

Ask Ken about the heavier valve springs, use a 7.3 rocker because they are stronger.

Stage 1 injectors.
One of his custom IP's.

A bit of head porting and port matching.

A big ram air to feed the turbo helps.
A big exhaust pipe is also a must.
The crankcase vent has to go somewhere other than into the intake to the turbo, at 22 PSI boost it starts sucking oil out of the engine.

So there you have the list to build a not quite stock engine.

I will also warn you, running it on the road can get expensive.
If I run mine hard the fuel mileage is in the single digits with an empty truck.
But it sure is a lot of fun when a Dodge or Stroke wants to blow that old diesel off the road.
They can out gear me in the end, but I can make them work for it up to 100 MPH if I don't mind paying for the fuel.