DeathByNissan55

I have an post-2001 gen 3 LQ4, freshly rebuilt short block with all clevite bearings and arp bolts. stock bore, stock dished pistons, stock rods, stock crank

Just found out I have to take crank out to swap to 58x reluctor wheel and sensor, contemplating rebalancing rotating assembly.

Since I'm already going to pay out the butt to get that done, I figured I should just get gen 4 rods since they will be beefier - justifying a rebalance.

The point of the post is, I'm trying to find which length rods or which engine model gen 4 rods I'm supposed to be looking for if I want to reuse the gen 3 dished pistons (unless there is an equivalent gen 4 piston/rod assembly i could get) and the gen 3 rod bearings (that literally havent even seen life yet, just assembly)?
I would prefer to find used gen 4 rods or rod piston assembly that would work with everything else in this engine.

I just don't know how to word my searche for this to yield useful results, especially when you can get aftermarket length rods, please help.

KCS

iTrader: (20)

The Gen III pistons won't be compatible with the Gen IV rods unless you have some weird ones with a c-clip groove in the pin bore (doubtful).

DeathByNissan55

Ok, good info, that answers part of it, but brings up a new question.

So since I can't use pistons, will the rings still fit the gen 4 pistons?

Also, as part of the original question, what gen 4 engine model should I be looking to salvage piston/rod assemblies from so that I can reuse crank, rings, rod bearings, and arp rod bolts, and hopefully wont be taller pistons where I pass through the plane of the block/head?

KCS

iTrader: (20)

Probably not, depends on the pistons. Some used thinner 1.2mm and 2.0mm rings instead of 1.5mm and 3.0mm rings.

DeathByNissan55

This is the only picture I have right now of the LQ4 pistons I currently have.
The engine has been saran wrapped ever since.

JoeNova

Why the need to swap to a 58x reluctor?

Any 05+ LQ4 is going to have floating pin rods/pistons with a dish.
The gen 4 rods are the exact same for everything from 05-current (yes, even gen 5 engines) that came equipped with a 5.3/6.0.

DeathByNissan55

I will be using an electromotive Tec3 standalone ECU, requires a 60-2 (58x) trigger pattern to work. I already bought the 58x reluctor and the matching crank sensor so I can make it a clean install.

However, I'm starting to contemplate installing an externally mounted trigger wheel because this is starting to add up.

My LQ4 is from 2002 I believe, so I could just find a junkyard 06 LQ4 and use the pistons and rods and those will be the beefier ones?
Also, are the gen 4 pistons taller at all?, because it sounds like gen 4 rods are same length as gen 3 just beefier.

BigEd_72455

iTrader: (7)

Gen 3 and Gen 4 internals will swap out. Piston rings are different, as are the pin style. You can take all the stuff (crank rods and pistons) from a gen 4 block and put them in a gen 3. If you go from a 24x to a 58x reluctor, you have to swap the crank trigger.





You can put Gen 4 rods and pistons on a Gen 3 crank, and vice versa. But you can not ONLY swap pistons or ONLY swap rods.


5.3 and 6.0 crank is the same size. Same stroke, and same bearings.

I have a crank in my Gen IV 6.0 that when I look up the GM 12xxxxxx part number on ebay pops up a bunch of 5.3 cranks.

If you are only wanting to swap to a 58x reluctor and are using a stock crank, grab one off ebay that is already a 58x for ~100$ and have the machine shop polish it and just swap them out. Saves worrying about a misaligned reluctor wheel.


I do know for certain that the new MSD 6014 ignition box uses any combo of 24/58/1x/4x crank and cam triggers. One of them requires an adapter, but the rest work. The box picks it up automatically when first cranking the motor over. But the new box does not have anything in the instructions about being able to be used with EFI like the 6010 and 6012 do.

Gen 3 pistons use 1.5mm/1.5mm/3.0mm rings, and the Gen 4 use smaller rings. I can not think of the numbers for them, but someone mentioned them earlier.

BigEd_72455

iTrader: (7)

KCS mentioned them. 1.2, 2.0

DeathByNissan55

So correct me if I'm misinterpreting what you wrote.
I CANNOT take entire gen 4 piston/rings/wrist/rod/rod bearing assembly and bolt it to my gen 3 crank and slap in gen 3 block? I can either use gen 4 piston/rings with gen 3 wrist pin and rod and rod bearings, or gen 4 rods and rod bearings with gen 3 piston/ring/wrist?

JoeNova

What? He didn't say anything close to that.
He said "But you can not ONLY swap pistons or ONLY swap rods".
Why would you try to mix and match wrist pins and bearings?

If you use Gen 4 stuff, it has to be all gen 4 stuff (other than crank).

DeathByNissan55

OHHH, ok I see which word I missed.

So I should be looking for gen 4 LQ4 piston/rod assemblies, understood.....I probably can't reuse my arp cracked rod style rod bolts can I?

Also he said bearings are the same, so since my clevite rod bearings are brand new, I can use them with gen 4 rods, right? or is it truely use all gen 4 stuff i.e. have to buy new clevite gen 4 bearings? lol sorry just trying to save money

JoeNova

I'm not sure on bearings. I usually just order OEM bearings for whatever year I'm working on.

BigEd_72455

iTrader: (7)

If you have NOT started the motor with the new bearings, you should be fine so long as both cranks are the same. By that I mean both cranks are std size bearings, or 10 under, etc etc etc...
just get some plastigauge and check your clearances.

and ARP bolts are re-usable, just make sure you don't mix up the caps to rods.

DeathByNissan55

Nevermind, assuming there isnt wear on the gen 4 rods, and after resizing them for arp rod bolts (which I actually should be able to reuse), I should also be able to reuse rod bearings......
My reference: http://www.lsenginediy.com/ls-engine...ection-guide/#
I believe I have the hardcopy of this book laying around somewhere.

Now comes the fun part - going and finding 05+ 6.0L dished piston/rod assembly (still called LQ4 engine I think?)

JoeNova

Don't gen 4 rods use bigger rod bolts?

ARP rod bolts are a pretty poor idea anyway.

DeathByNissan55

Thank you for all the help.
Now comes the search and cost analysis to see if I can avoid all the machine work and just use HPtuner and still have the same tunability that I would have had with Tec3.

BigEd_72455

iTrader: (7)

not to my knowledge. I have a set of gen 3 and gen 4 rods at home. I can look when I get back home.

and why do you say ARP rod bolts are a poor idea when they have a much higher tensile strength that stock rod bolts.

DeathByNissan55

why? references?

I was told arp rod bolts are the way to go if you resize rod.

BigEd_72455

iTrader: (7)

Hp Tuners, by what I have read, will adjust and modify any oem parameter in the computer. Again, by what I have read.