mean lx

I hope to purchase an '02 C-5 in May and was wondering if I purchased a 402 short block and added Afr 225 heads, everything else needed would swap over from the LS1 to the 402, Correct? Also, most of the 402 shortblocks have forged cranks, rods and pistons, which should handle lots of boost, no ? Thanks, James

0Randy@DRM

You will need a Racetroix wiring harness adapter. ABout 100 bucks and well worth the money.

Randy

Cajundude

You would need new valve covers and valley cover. You need to extend your cam sensor wires to the front of the engine and relocate your knock sensors to the sides of the block. Intake will transfer just fine. You would want compression around 9:1 along with the forged internals for your boost needs.

mkern1

There are some parts/issues that need to be addressed when doing the swap.

I'm in the process of doing the swap and this in what I have come up with so far:


1. LS1/6 Knock Sensors need to be relocated with an extension harness.
2. Cam Position Sensor needs to be extended to the front of the block.
3. LS2 Valley Cover, Rear Cover, Front Cover W/cam sensor, LS2 Timing Chain/gear need to be purchased.
4. I also just found out that the head studs I'm using for my LS6 block in my 02 Z06 won't work with the LS2. I think some of the studs are longer on the 2004 and up blocks. ( Can someone verify this!)
5. You need a ls1 (24 tooth) reluctor wheel on the crank for it to work with the ls1/6 pcm. Don't use the LS2 reluctor wheel.

All the other seals and gaskets work for both ls1/6 and ls2!

jhong321

You would also need ls2 lifter trays and make sure your put some washer in the windage tray so your crank bolts will clear.
You might want to check out ls1tech.com for more info. If you go this route make sure you upgrade your clutch to hold all the torque that you will be getting from your 402

Cajundude

You'll also want to shim your rockers up.

mean lx

Thanks for the replies. I have read somewhere that the aluminum blocked 402 would not work with the 2004? and earlier knock sensors. Does anyone know why or if this is even true? Thanks, James

jhong321

the ls2 402 block will bolt in fine there are just a feww little things that you would have to do. besides that was mentioned above.
the knock sensors will have to be relocated to the side of the block.
and you will have to grind a small part of the block to get the motor mounts on. As for where to get the ls2 402 i did some research on this and got mine from SDPC they have great service and a good reputation plus will suply you with most of the stuff you will need to do the conversion.

Shane_S

If you're going to go with that much power you might want to consider a FAST 90/90 intake/tb setup as well.

Otherwise all of the other advice, Especially Mkern1's should be followed in preperation for the swap.

Cajundude

Fwiw, I did not have to do this. My motor mounts were fine.

Miles in Michigan

Is the 2002 motor mount different than the previous years, or is it possible the place that sold you the block already ground that down, knowing it'd be going into a C5?

I have my LS2 in my car, bolted to the torque tube, and can't put on the passenger side motor mount. So I either find a motor mount like yours, or take the 4 1/2" angle grinder to the block, while it's still in the car. I really wish I would have checked this before installing. I actually had the drivers side mount bolted up when the engine was on the stand, and was about to put on the passenger side too, but then decided they'd just get in the way when dropping it in, so took dr. side off without ever trying pass. side.

mean lx

Well, I decided to go a different route. I bought the entire top end for a 427. Now, I just need to purchase another LS1 or LS2 block and have it sleeved. I will be building a 427 and hope to put around 600 horses to the rear. Should be enough to get her into the mid to low tens. James

mkern1

I have an 02 and had to use a grinder on my LS2.

mdhmi

No!.

Boosted motors have lower compression and special coated pistons and sometimes different rings depending on how much boost you plan to run.

I would not assume that any ole 402 will be boost friendly.

Mark

Shane_S

Agreed. and stock internals will give you a 10.5:1 compression ratio. you want 8.5-9:1 ideally for most boosted applications.

Shane

mean lx

Yes, I'm putting together my motor and will use the same brand piston I have always used (BRC). I will not be buying "anyone's" shortblock, but designing my own. In power adder engines, it is better to have the top ring land moved further down the piston for durability (less heat). In the last motor I built (N2O), I used Hellfire rings, which would also work great for a boosted application. I am leaning more towards just having a N/A motor with the possibility of a small shot of nitrous (200 hp). James

mean lx

I would think you could order one with the compression ratio you wanted. However, I plan on putting together my own engine. I am well aware of the fact that a lower compression ratio works well or is less temperamental with boosted applications. James

402Sam

Call Scoggin and dickeys, they are a forum vendor here. They have a ls2 402 short block for alittle over 4k. It is a complete kit that comes with all the necessary knock sensor relocators and cam sensors relocators and valley cover. It what I am dropping in my car now. Could not have asked for a better motor kit swap then this one. Their site is sdpc2000.com

mean lx

I already have the top end for a 427 engine. I will have an engine sleeved for a 4.125" bore and slip in a callies crank, and BRC pistons. I am undecided as of yet on the brand of rods. I need to do some research. I am already committed to a 427. Just not sure of the power adder as of yet (If I will use any at all). I am shooting for 600 RWHP N/A. That should put me into the low to mid ten second range. If not, I'm sure a 200 shot wouldn't hurt. James

davisce

KOOL

I did an engine SWAP in my 1999 C5 Coupe as well. I bought a new GM LS6
405 HP Crate Engine then had a 475 HP Head and Cam package from Hinrik's
Auto Racing Engines installed before dropping it in my 99 C5.
I'm still in the brake in stage, so I haven't been able to see just how hot
this thing is, but I it's defiantly got more punch than my old 345HP LS1 engine

By using the LS6 engine I didn't have to replace the wiring harness either.
Good luck on your SWAP. . . . keep us posted on your progress.

Later,[/B]