LB7: The Rebuild, Ch.2 -- Building slowly

[TNRGreene]

Tom Best of luck with your build. Cut the pistons, it can't hurt

Oh ya & since the motors out you are officially out of the "borrowed time" club. Please adjust your signature accordingly :rofl:

 

[TrentNell]

No, the bent ones in my LB7 are the weakest. LBZs are slightly stronger. Im hearing that the LMLs may be stronger yet.




Josh, thats always a possibility to cut them. Eric's advice is to cut them, too. We'll see whats up when I get the heads off. I may be forced to cut them to clean the lips up. Im just not sold on the need to do it for my situation. Its kind of a unique in that I am not using larger turbo(s) or dual fuelers like most people would do trying to hit 11s, which pretty much requires cutting pistons, hence my thinking of keeping compression high.

Tom , do yourself a favor and delip the pistons , because you not putting on a bigger turbo , or injectors IMOP your pistons are at a bigger risk them most because of the stock turbo and stock injectors , stock pump, it meens big Pulse width and poor pressure to make power , neither are good for EGT's .

 

[Jared Duramax]

I say cut the pistions you wont really loose a whole lot of power from the lower compression but you will deffinatly save yourself the time from having to do all of this again when a pistion pops

 

[TheBac]

Tom Best of luck with your build. Cut the pistons, it can't hurt

Oh ya & since the motors out you are officially out of the "borrowed time" club. Please adjust your signature accordingly :rofl:

Done. Thanks for pointing that out.

 

[TNRGreene]

done. Thanks for pointing that out.

lol

 

[SmokeShow]

now you can name the truck "time ran out" :rofl: :hug:

 

[TheBac]

Theres a lot of guys who could say that. I figure my problems are minor.

 

[bullfrogjohnson]

Yeah when time runs out and leaves a hole in the side of the block, the problem's list gets a lot longer

 

[TheBac]

Smile! God Loves You!


I found this oil/grease smear on my pass side valvetrain while tearing the motor apart today. :rofl: I think Ill use that as an avatar.


Here's the pics I took. I labeled the piston pics so you can tell them apart.
http://rides.webshots.com/album/576875484rxNyiW

I certainly learned a lot about taking a Dmax apart today. Good Lord is that a complicated mess of wires and fuel lines. Everything came apart without incident, although a couple wire connectors are going to need new plugs now. Damn things were already dried out and cracked when taken apart. (yes I used a pick tool). Also need to re-loom most of the wiring, as it is dry and brittle.

As per everyone's recommendations...every bolt is either back in its spot or in a marked bag. All the injectors are in their own bag, too. Engine is in a garbage bag on stand (see pics).

Heads looked good. Valves are sooty, and some yellowish residue around the injector tip area. Valvetrain looked good. Surprised how easy it is to do injectors. Yeah, right.

Pistons are very sooty, with some heavier carbon buildup on #8 and #1 (which IIRC were the worst rods). No erosion of the bowls, either. I think I could reuse them.

Injectors, though...lots of rust in the fuel inlets. Lots of carbon on the tips. Looks like I AM buying injectors. Ah well. Also popped the sleeves on #2 and #7. Nice.

Hopefully I can measure protrusion tomorrow and then get the short block torn apart.


DO NOT expect me back on the road until fall. This is gonna take a while.

 

[02bigstrokin]

Injectors, though...lots of rust in the fuel inlets. Lots of carbon on the tips. Looks like I AM buying injectors. Ah well. Also popped the sleeves on #2 and #7. Nice.

the rust in the fuel inlets is probably from the injcetor lines that go through the valve covers to the injector body. when you break them loose they drop all that rust in the inlet. i flipped out the first time i changed an injector in mine because of all the rust but then somebody told me about the corrosion on the lines. i just cleaned them out.

 

[TheBac]

Thats what I figured, but its still not encouraging.

Another thing...headgaskets were B's on both sides. Both of them looked perfectly fine. No odd coloring between cylinders, no indication of water going anywhere it wasnt supposed to.

 

[TheBac]

Well, Day 2 wasnt all that surprising.

Here are the deckheight protrusion numbers that Kole and I gauged:
1: -.025
2: -.007
3: -.001
4: +.004
5: +.004
6: -.003
7: -.006
8: -.029
While I wouldnt mind those numbers for an Olds, they arent exactly kosher for a Dmax. Pretty much follows along with the comp numbers. I tried finding OEM specs for protrusion for comparison, but couldnt locate them. Any help on that?

Took the pistons out next, and found all but one skirt in excellent condition, and I think the markings on the one are just carbon. Cylinders show minimal wear (some minor scratches). 1 rod bearing showed some center wear (I think it was 3 or 4), while most of the others showed wear on the outer edges, which I thought was strange. Never seen that before. Rod journals looked fine, though.

Rod #8 is clearly bent to the naked eye. #1 also shows a bit. The others arent obvious.

Now the interesting part. I cannot get the oil pump nut off. Is it reverse thread? Tried airgun, ratchet, breaker bar, but no joy. Had the crank braced, too. Why? Sadly, the reluctor gear is spinning on the crankshaft. I have a feeling one of the crank pins sheared. Trent, I dont think it'll be an issue getting that wheel off now. So if anyone has any idea how to get that nut spun off without destroying anything, let me know. I have to go to Sears tomorrow and buy a socket set to get the cam bolt off anyway. I take it that its a 27mm 12pt?

I moved all the pics to Photobucket. http://s762.photobucket.com/albums/...ramax Engine Teardown/?action=postuploadshare Webshots had too many advertisments.

 

[zlonsway]

On your oil pump there should be a hex that you can put an allen wrench in to hold the pump while you break the nut loose. Don't recall what size allen wrench it takes. that is how I broke mine loose and also torqued it back down.

 

[TheBac]

Cool. Will look tomorrow. Thank you. Eric told me using the impact is what broke the pin. Whew.

 

[JD4440]

really think it'll take till fall Tom ? Looks like your making good headway

 

[TheBac]

really think it'll take till fall Tom ? Looks like your making good headway

Taking it apart is the easy job, at least if I know what Im doing. But Im looking at about $3k in rebuild/perf parts plus upwards of $1k in machine work/labor costs. Money is tight right now. It'll get built as $$ allow, which means slow progress.

 

[JoshH]

Tom, that head gasket sheet that has all the specs and ID info has the piston protrusion for the different head gasket thicknesses.

Looks like Grade Bs have protrusion of 0.0108-0.0128 in.

 

[JD4440]

Taking it apart is the easy job, at least if I know what Im doing. But Im looking at about $3k in rebuild/perf parts plus upwards of $1k in machine work/labor costs. Money is tight right now. It'll get built as $$ allow, which means slow progress.

I completely understand. I'm pricing options and I'd do good to get it in that time frame as well using the original motor

 

[TheBac]

Tom, that head gasket sheet that has all the specs and ID info has the piston protrusion for the different head gasket thicknesses.

Looks like Grade Bs have protrusion of 0.0108-0.0128 in.

Thanks Josh. All the rods were all pretty well fubar'd. How the heck one didnt break and make a picture window is beyond me.

 

[durallymax]

Hey just found this thread, thanks for the pics they are great, and thanks for moving them. Now I just gotta get in gear and add them to the write-up.

as stated for the oil pump, insert an allen head (6mm IIRC) into the spot where it fits. Cant really explain it in words. Its on one of the gears in the pump, you will see it spin as you turn the nut which is connected to the other gear. That nut is very tight, helps to have one person hold the allen and another break the nut loose.

As for the flywheel bolts, make sure you use new ones. They are very tight, i use an impact to zip them off, my 1/2" didnt have the balls so I had to use the 3/4. The torque spec on them is as follows.

58lb-ft
60degrees
60degrees again

below is the pattern

I have to do these with a huge cheater pipe with the truck all the way in the air on the lift, but im a tall skinny guy and dont weigh much. A torque multiplier really helps.

If you dont have a torque angle meter you will need one for some parts of the build.

You will also need a flywheel hold tool or make your own for torquing the balancer bolt and flywheel bolts.

Hope this helps.