Disclaimer:New forum member (please go easy on me)

After finally buying my childhood favorite car last February, I didnt even get to drive the car for a full year when last week the timing chain snapped at about 5k rpms while shifting from 3rd to 4th. Needless to say that I am quite bummed. According to the dealership I have like 4 impacted pistons, bent rods, bent valves and the heads are marred. They are in the process of pulling the block to see if it is salvageable.

The car in question is a 2006 Black z51 MZ6

So here is where I need your expertise/guidance/advice. Ive read so much on the ls2 ls3 combo my head is spinning. I was thinking of placing Ls3 heads (fully assembled) with upgraded springs on an LS2 block. I just figure this will make all wiring and accessory mounting the same and therefore save time and money. I will be using another mechanic instead of the dealership. Of course I would also like to put an aftermarket cam on the build as well (why not?) Headers and exhaust are already on the car. Plan on a vararam install.

Ive read so much on the ls2 ls3 combo my head is spinning

Goals: 1.Reliability 2.Reasonable cost 3. About 450/450 to the wheels

Questions:
Should I say screwit and find a rebuilt LS2 and not blow the extra $?
What cam for my goals?
Mill the heads and buy/flycut pistons for the extra compression?
Different valves?
What brand pushrods,pistons, springs, gaskets etc to buy?
Would you reuse crankshaft and connecting rods? (odometer:91991)
And now that I hate the word timing chain, which one to buy?

Thanks for your time in helping me out in this difficult separation I am currently experiencing with my car. It is much appreciated.

Britt


PS: For reference I have read spinsmonsters writeup, a couple of other ls2 with ls3 heads threads on this site, and the PatrickG writeup from another site. Along with writeups on l92 heads from hotrod and I think super chevy. All the different and sometimes conflicting data/info is just a lot to process, and leaving me needing some help.

 

OP: What is your location? City / State.

 

With the expense of a rebuild, you might consider taking a look at the GM Performance Parts Catalog for a crate engine. A new LS3 with a 2 year warranty is a little less than $8,000 complete and ready to bolt in.

 

Located near Raleigh/Durham NC. Any input on any one question will be of great help.

 

Is much involved in doing a ls3 swap into an ls2?

 

If you decide to replace the timing chain in any motor build, take a look at the hinson c7r timing chain:

https://www.hinsonsupercars.com/p-29...ing-chain.aspx

 

OP

You need to state your desires here. Do you wish to get rolling again with the least money out of pocket or are you thinking you may as well turn this disaster into an opportunity by taking what's good left and turning it into your dream car.

This is like what's happening to some Porsche V8 Cayennes. They score the cylinder wall which demands a whole engine rebuild. This costs roughly $35k at the dealership.

For less, there are some superb indies doing not only a rebuild better than the OEM one, but punched out making for a super Cayenne which is a heck of an SUV.

You are in Chevy-ville meaning unless you want a full on competition engine, you aren't going to brush those numbers but the same applies here. You need a rebuild or a swap or a crate engine. What is your budget and what is you dream?

 

I would get a basic rebuilt shortblock, aftermarket cam, then ported stock or trickflow heads.

 

Welcome to the club. Same thing happened to me a couple weeks ago. Except mine had 65k miles. Did you happen to have an underdrive pulley?

I'll be following along to see what you decide to do. I plan on doing heads cam intake if the shortblock is ok.

 

Somehow, on an engine where the chain has snapped/broken and parts have been damaged, I just can't imagine reusing them---but I admit, that's just me. I could be wrong.

If it were me, seeing that you are in the Raleigh/Durham area, Mooresville isn't that far away. Here on CF, there's a vendor tuner, named JHR in Mooresville, fellow there named Zach. (https://www.corvetteforum.com/forums...rformance.html) Maybe you don't want them to do the work for you, but asking them these type of build questions seems like a good idea to me, and you may want to get some of the parts from them as well. It doesn't hurt (and helps in my mind) that Anthony at LGM recommends them as well as being a biz they've known and done biz with for quite some time. Good luck with it.

 

Thanks for the point to that timing chain! Hadnt seen that model, only the c5r and lingenfelter iwis. That will definitely be going on the build if that is the route I take.

 

Im very wary of reusing parts as well, its a scary thought. I have heard the name before, I will definitely be looking for a good tune at the very least so I will have to give JHR a call when I find out the final damage and what I will need.

 

This is the direction Im leaning. Im just hoping my block wasnt damaged and then it will definitely be the way I will go about rebuilding the engine. Though the price on the trickflows gives me pause, ls3 heads $500 assembled vs $1200 tricks.

 

No ud pulley. Im in the same boat, fingers crossed the block is ok. If so I want heads cam intake as well.

 

Ok, I was wondering if you were near the Houston Texas area. As for high quality after market parts, please take a look at these items.

http://store.katechengines.com/dampers-c41.aspx

http://store.katechengines.com/bille...sioner-p2.aspx

http://store.katechengines.com/c5-r-...chain-p30.aspx

Good luck with your build / repairs.

 

Did the dealer fully disassemble your engine? They might have just saw the lack of cam sensor signal, run a compression test and maybe pulled a valve cover.
That sounds like a lot of damage from a timing chain failure!
Normally when an engine loses a timing chain or belt, it bends a few valves and that it. You can see marks on the pistons where they hit the valves but they are not hurt. Sometimes a head can get damaged if a valve gets smashed into it. Bent rods are highly unlikely.
Get the car to someone you can trust to pull the heads and timing cover and go from there. It's very possible you can reuse the short block.

 

Thanks for the advice. The dealership said the timing chain was in the oil pan. Don't know about everything else. They said the heads were probably salvageable, but I would like better performing ones anyway. I plan on having the car taken to another mechanic for the build because as you stated I would rather have someone I trust work on the car. I am also going to ask the mechanic to go by the dealership to look at the work they've done. They have said they pulled the heads and are in the process of dropping the block. And this process was started last Monday. I am growing impatient and have let them know so. They only have one mechanic certified to work on corvettes. I am more wary of them every time I call for updates.

 

This is true! However, that one mechanic will probably be the only GM Master Certified Tech at the dealership, whom oversees the work of all of the other dements that the dealer hires. I doubt he will be wrenching on your car.

You're better off taking your car to a pro shop. You're in the heart of NASCAR country so it shouldn't be too difficult to find someone.

 

My buddy who is a long time member on this forum has an "almost new" LS2 that was built by Cartek with the best of the best parts for sale. You can contact him at his email address... racing1320@aol.com ...about it. The list of parts in the engine are all top notch from Callies 4340 4" crank, Manley H beam rods, Wiseco forged 403 CID pistons, ported FAST intake Stage 4X Cartek heads...and more. I'm sure you'd be surprised how inexpensive the engine would be if you contacted him.

 

Thanks, I'll keep that in mind if I need an entire engine and the block on mines wrecked.