Armycop

Hi All!

After 64,000 miles and smiles, many of them on a road course near you, I've decided it's time for more horsies under the hood. To that end, I've procured a lightly used LS2 engine out of a wrecked 2007 Trailblazer SS.
Many of you will chime in with "shoulda gone with an H/C/I setup noob", but that's not what I hope to discuss here. I didn't, and we won't, okay?

The replacement engine is complete, down to the fan. My plan is to use the stock wiring harness and PCM, swap in the stock manifold and TB, stock oil pan assembly, and other accessories as needed. I've done the Search thing and can't find a thread that tackles this specific swap, so if you know of one please post up a link. No sense in re-inventing, right? I'll post pictures as it progresses, promise.
I won't be doing this alone either. I've got a local builder up in Walled Lake who'll be handling the heavy lifting (actual engine pull and install, since my garage isn't big enough) and to guide me along.

I do know I'll have to swap out the reluctor ring (ugh) and replace my cam sensor as well, plus extend some sensor wiring (name escapes me right now) and maybe relocate the knock sensors. There's a ton of stuff I'm missing, I know, so feel free to add to the list!

I'm headed up to the shop today to start tearing down the replacement and prepping for the swap. Pictures when I get back!

Mike94ZLT1

Rather than tear the engine apart, why not get the converter box from LPE? I'll respect your request and keep my mouth shut about your method of looking for more power, but if you are going to tear it apart and put it back together stock other than a reluctor ring then...

Who is doing the install? (I live in Livonia, just curious)

Armycop

There's a converter box for this build? Did not know that! If that means no taking out the crank I'm sold. I'll contact LPE for more info. Thanks Mike.

As for the teardown, well, since this is a used engine, I wanted to ensure that everything was in good working order. As you can see I'm quite happy with its current condition. Look at that beautiful crosshatching on the cylinder walls.


This was what I started with this morning. Already removed the intake before this pic was taken:


Here's where I'm at after today:
Pile of parts...


nekked block:



The shop I'm using is owned by a friend of mine, Kenny Walters, of Mufflers and More in Walled Lake. He was gracious enough to let me participate in the swap. He'll clean up and square the heads for re-assembly. We'll be discussing cam selection this week as well.

Mike94ZLT1

http://www.lingenfelter.com/mm5/merc...gory_Code=C163

Armycop

Yup, already ordered, and the knock sensor extension kit too! Thanks again!

YELLO C5

I'm looking for at least a new short block and I see Trailblazer SS LS2 motors going for $2500 with 47K. How did this swap go? Was it as straight forward as it seems?

What did you build? Results?

Armycop

Forgot all about this thread!
The swap was too much for me to do in my unheated garage in the middle of an MI winter, so I farmed out the work to a speed shop I'm familiar with locally.
-They did a body-off conversion; makes for a much smoother swap.
-The LS2 bolts right up to the LS1 mounts, you have to change out the motor mounts from the LS1.
-The oil pan is also swappable, which you'll need to do as well. Recommend a new oil pump/O-ring for the pickup.
-We found the 2006 LS2 uses the same 24-tooth reluctor ring as my 01 LS1, so I didn't need to use the Lingenfelter signal converter. But, do get the knock sensor harness; it's longer and allows you to fit/use your old sensors into the side ports on the LS2 block, which is the stock locale for the sensors. Oh, and if your LS2 comes with the grey knock sensors you'll have to switch them out with your old black ones from the LS1.
-The bell housing mounts right up as well.
-If you opt for keeping AC (I did), you'll have to reverse the LS1 AC pump mount in order to line up with the AC pulley.
-The LS1 intake swaps on, as does the valley cover. Obviously, plug your now-unused knock sensor ports lest you lose lots of vacuum and oil! We also kept my LS1 throttle body, to make for less computer confusion (drivebywire and all that).
-We had the heads checked, decked and rebuilt with stiffer springs, new valves, keepers and guides. After a Dr. Phil tune, I have a valvespring-induced resonance drop-off at 5500rpm's that I have to address with dual springs. Comp Cams says it's not their springs, but I trust the good Dr. more.
-We did drop in a hotter cam and re-used my Kooks 1 3/4 long tubes, so she breathes out real good. I suspect the stock LS1 intake and TB leaves some HP on the table, but I haven't found an LS6 intake and TB for good money yet.

Now the bad news. I got it back in February and after driving it to/from work and about a total of five times, I started getting a serious knock coming from the engine after 10-15 minutes of driving. turns out I had a lifter go rotate in it's keeper, grinding down the cam lobe to a circle. Trashed the lifter, the cam, and spread metal into the oilpan. The resultant rebuild and new parts was covered by my speedshop (bless those boys!). So in went a whole new set of lifters, lifter keepers, new cam, four complete engine flushes and filters. Got the car back from the re-rebuild in April just in time for our first track event. This was before the Dr. Phil tune, but the car was fantastic. ALL kinds of grunt down low and stupid power up top.
After the Dr. Phil treatment I've got 406HP and 409TQ at the rear wheels. I'd say a successful swap!
All told the build cost me $7200, including shop charges.

DARRYLZO6

Thats great and Im glad it worked out. Kind of a blessing in disguise having to get the second repair and over 400 rwhp is all good. Post some pics of the finished result. Also look towards Ebay or Craigslist for a used intake and throttle body. You should be able to find something in your price range.

YELLO C5

Thanks for the update. What cam did you go with? I have RHS LS1 heads and probably will keep those but I wonder if the LS2 intake flows much better than the LS6 I have.

dan1546

Nope. The LS2 does have a bigger snout and when ported is about on par or a bit better than an ls6. Not worth swapping an ls6 for an ls2 though in my opinion.

Noma01

Good info!! I got a tbss motor I'm wanting to save for the vette so I can put a forged block in the tbss !

Armycop

Here's the camshaft specs I went with:
Summit Racing Part Number:CCA-54-424-11

UPC:036584068235
Cam Style:Hydraulic roller tappet
Basic Operating RPM Range:1,500-6,800
Intake Duration at 050 inch Lift:212
Exhaust Duration at 050 inch Lift:218
Duration at 050 inch Lift:212 int./218 exh.
Advertised Intake Duration:265
Advertised Exhaust Duration:271
Advertised Duration:265 int./271 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:0.558 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:0.563 in.
Valve Lift with Factory Rocker Arm Ratio:0.558 int./0.563 exh.
Lobe Separation (degrees):115

chaase

YELLO C5

Very nice! I assume it idles pretty smooth, almost stock like yet puts out +400 HP. I'd be very happy with that.