BaggerDad

Anyone swap out original engine to a 2008 LS3?

TLS_Addict

Is there an issue with your LS2? LS3 top end will bolt to an LS2.

If your bottom end is good I would t go swapping out your engine for minimal size increase. A cam, LS3 topend kit and make some really good power.

BaggerDad

Thanks, problem is bottom end. sounds like rod knock, thus thinking of LS3 install. It's been years since I did engine work and have not kept up with all of the do's and don'ts.

TLS_Addict

You definitely can swap in a LS3. If it's just the crank why not do a mild stroker build? Problem I see with LS3's is that to find a good used one can be difficult if you want a good deal. A crate engine is a good option but it's expensive as well.

subfloor@centurytrans

It's a relatively straightforward swap. You'll need some different wiring connectors but the biggest thing to note is that you have to change the reluctor wheel on the crankshaft because without doing that the engine won't even start.

The 2005 had a 24 tooth reluctor wheel but it changed to 58 starting in 2006.

TLS_Addict

Or, OP, if you want to sell the car and find a running LS3 you can do that. PM if you want to sell.

I forgot about the 24/58 reluctor change. My brain always Says LS2 = 58.

BaggerDad

Looking at a complete LS3, minus throttle body and intake. So what you're saying easy swap change a few wiring connectors?

BaggerDad

I thought about replacing crank and cam for added power. LS3 is a good engine, saw dyno just before it was pulled out as owner bought a LS7.

subfloor@centurytrans

Straightforward - yes, easy - not so much.

What will likely be the most expensive and time consuming part of the swap is the reluctor wheel change. Even though it sounds simple you're almost doing a partial rebuild of the engine at that point. In order to change the wheel the crank needs to come out of the engine which means you'll need new rod and main bolts as well as rod and main bearings. You might be able to reuse the bearings but the rod and main bolts can't be reused since they're torque to yield.

Here's everything else I could think of:

• Change to a 24 tooth reluctor wheel as I already mentioned. Although Lingenfelter actually sells a box to allow putting a newer motor in an older car, I'd highly recommend not using it.
• Tune change is necessary if you use the LS3 MAF and injectors.
• The MAP sensor and/or connector might need to be changed depending on how new the LS3 is (as I think they changed around 2010).
• You'll need a cam sensor conversion pigtail as the connectors are different between the two engines.
• The cam timing gear needs to be changed to the older style 1X instead of the 4X the LS3 has.
• If you run the LS3 MAF you'll need a conversion pigtail for this one too.
• Whatever exhaust is on the car will work just fine with the LS3 as I ran LS2 headers on an LS7 for years and went 9.950 with it.
• As long as it's not a dry sump LS3 you can use your oil pan, engine flywheel and all the other external accessories.
• If it is a dry sump motor then I'd say it's time to find another donor motor since that opens up a whole list of other issues to deal with.
• You'll need to make sure the motor has the intake manifold since the one from the LS2 will not fit on the LS3.

If I think of anything else I'll come back and update the thread.

BaggerDad

Can't thank you guys enough. Since changing out the reluctor basically is a bottom end rebuild. I may as well keep what I have and change out the crank, new rod/ or rods, bearing sets and all bolts associated with bottom end rebuild. Anything else I should be looking at?

subfloor@centurytrans

If you're just rebuilding the bottom end then there's no need to replace the crank or rods as long as they check out okay at the machine shop.

Having done this too many times to count, here's what I'd recommend doing:

• Light hone on the cylinder walls
• New piston rings
• New rod and main bearings
• New cam bearings
• New rod and main bolts
• New timing chain
• New lifters
• New head gaskets
• New rear main seal (these frequently leak, so it's cheap insurance to do while the motor is out)
• New front timing cover seal (also frequently leaks)
• New oil pan gasket
• New oil pump (probably not needed, but also cheap insurance)

Some people also tend to replace minor parts like the intake manifold gaskets, timing cover gaskets, exhaust gasket, water pump gaskets etc. but unlike the old school days these can be reused multiple times without issue.

Red06Vette

Unless you're going for higher HP, you could also get your current heads freshen up and maybe ported and have your current intake port matched. Put these on an LS3 short block.

BaggerDad

Thanks for the check list, reason I mentioned crank is that there is a noise like a rod knock, oil pressure appears normal.

subfloor@centurytrans

Cranks can be turned (also known and cutting). It takes quite a catastrophic event to render a crank unrepairable.

BaggerDad

Definitely worth looking into. Thanks for your help, I now have a few options, didn't think of using current crank. I'll keep you posted. Thanks again!

BaggerDad

Hello, I see that you have done more than a few engine swaps / rebuilds. Would you be interested in rebuild for my car? Thanks, Larry

subfloor@centurytrans

Not sure if you were referring to me, but it would depend on where you're located.

BaggerDad

I'm in Florida, but am willing to ship.

subfloor@centurytrans

As much as I'd like to help, you'd be better off finding a local shop because I'm sure the shipping costs would be pretty expensive. Plus, rebuilding an LS motor isn't rocket science meaning any semi-competent machine shop should be able to do it.

BaggerDad

I appreciate your candor, problem is Florida has reputation of taking your money and no delivery. I'll start the process of weeding out the bad, don't have a good feeling on being successful. Thanks again for your input.