Generation IV Internal Engine - Can I put an ls2 rotating assembly in an ly6 block?

I'm getting an ly6 with almost no miles on it for dirt cheap with a spun bearing, figure since I'm taking the crank out I might as well look into other options, and an ls2 rotating assembly seems to pretty well meet my goals considering I'll be starting off with l92 heads, ditching vvt, picking up an ls3 intake, all in all if this is possible/ a good idea, i can walk away with a pretty bad ass budget motor.

my question is, is there any reason NOT to swap in an ls2 rotating assembly? and I keep hearing that most of the cranks are the same but that some are different, would the ly6/ls2 crank be the same?

I got a 2011 ls3 intake FS if ur looking. 25miles on it

w/ rails and injectors? how much?

and also, bump for my initial question

The only thing you need to watch out for is the block's bore size. To ensure longevity of the engine you need a freshly honed bore and new rings. Since your block can handle it, why not look into a L92 or LS3 rotating assembly? The bigger bore will be a great benefit and all you would need is new rings, bearings, and rod bolts. The L92 pistons even have valve reliefs already in them.

Pm sent

Ls3 has a 4.065 bore. So no you can't use an Ls3 rotating assembly. I would double check on the bore sizes on your block I'm not completely sure it's a 4.0 bore it might be smaller. Since it's out some bearings and a hone job would be a great idea and it's not expensive.

ly6 and ls2 are the same bore and stroke if im not mistaken

Your right I was mistaken it with a L76

L76 has the same bore and stroke as the ly6 and the ls2 also.

I would LOVE to run ls3 internals, but that would require punching the block .060 over, which seems like it would cause severe structural issues. the ly6 is a 4.0 bore block and so is the ls2, which is why I was figuring everything would work pretty well. the block apparently still has cross hatching in it, it was in a boat for about 60 hrs so I've been told, then water got in the oil and it spun a bearing.

at this point my question is, using stock ls2 internals, where should I buy rings, bearings, all that stuff from? actually planning to do a full rebuild on it, so is there a company that would be able to get me EVERYTHING including arp rod bolts and probably head studs too? and give me a discount for purchasing it all together? :D

What kind of parts do you want?

Stock, forged?
Why not forge it?
All you need are forged rods and pistons. The crank can take ALOT of abuse!

as far as rods/pistons I'm planning on just using stock stuff, I'm going to replace the crank with an ls2 24x crank since I can pick up everything together for around $350, then I don't have to worry about buying a converter box. Otherwise I'd have to get a 24x crank, then drop around $700 on rods/pistons. My goals for this motor are to keep it as budget friendly as possible, I don't want to boost it, I MIGHT spray it just a little, but thats about it. I'm aiming for somewhere in the 450-500 range (@ the crank, obv.) still have NO clue what kind of cam to get, but I'm a good ways away from that part right now anyway.

when I say 350$ on the rotating assembly, I'm referring to a used one, (just so I don't appear to be insane/stupid)

The LY6 block can be bored out to 4.065. If they were more commonly available you'd see more stroker builds using them. The 4.000 inch bore blocks usually end up being bigger which is why I suggest going to the L92/LS3 setup. By the time you hone an even slightly used 4.000 bore you'll end up with too much clearance for a hypereutectic piston. The L92/LS3 setup will cost a little more to run but it will be well worth it and you will more power. The factory stuff is great and you don't need forged components for your build goals. Hastings makes an affordable set of moly rings for both setups. The GM rings are pretty expensive but well made. I'm not sure where you can get all of the parts from one location but that's not a big deal.

The LY6 block can be bored out to 4.065. If they were more commonly available you'd see more stroker builds using them. The 4.000 inch bore blocks usually end up being bigger which is why I suggest going to the L92/LS3 setup. By the time you hone an even slightly used 4.000 bore you'll end up with too much clearance for a hypereutectic piston. The L92/LS3 setup will cost a little more to run but it will be well worth it and you will more power. The factory stuff is great and you don't need forged components for your build goals. Hastings makes an affordable set of moly rings for both setups. The GM rings are pretty expensive but well made. I'm not sure where you can get all of the parts from one location but that's not a big deal.

so wait, .060 over is actually "safe" on that block? once I build this motor and put it in I don't EVER want to take it out again lol. I just wanna build it, and do oil changes, and be happy

You won't be a happy camper boring it .065
It's not an iron block and even then it won't be as safe.

You won't be a happy camper boring it .065
It's not an iron block and even then it won't be as safe.

I was under the impression that a majority of the ly6's were iron blocks? I'm actually not sure whether this one is since its coated and I haven't had a chance to pull the casting number off of it yet since I'm still waiting to pick it up.

in any case, .065 did seem pretty excessive to me. with my goals and intentions as I stated them above, is there anything I SHOULD upgrade on the motor while I have it apart. assuming:
stock ls2 rotating assembly with 24x crank
aftermarket cam of some kind (no clue, dunno what I'm actually looking for other than power - sad, i know, but I came here from turbo cars so I know nothing about effectively choosing cams)
lL92 heads I assume I should upgrade the valve train for the cam
LS3 intake
arp rod bolts probably head studs too
ls2 front cover and whatever else I need for that to ditch the vvt

I'm planning to just do a full on rebuild on it and put new gaskets everywhere, is there anything other than rod bolts that are prone to breakage?

and my last major concern, the ly6 pistons have valve reliefs, where as ls2 pistons are flat top, will that cause me any problems? and if so, what do I do about it?

i have a ls3 tb, if you need one..

all ly6's are iron blocks. l76 i believe are aluminum. They can be bored out to fit ls3 internals no problem. As far as cheap dependable power, there is no replacement for displacement.

V8pwr has given you great advice. your going to have to overbore it anyway. why not go bigger?
If you just cant swing it. I see no advantage with the ls2 internals vs the ly6 internals other then flat top pistons. simply milling your heads a bit will do the same thing.
good luck either way you go.
bpatrol

all ly6's are iron blocks. l76 i believe are aluminum. They can be bored out to fit ls3 internals no problem. As far as cheap dependable power, there is no replacement for displacement.

V8pwr has given you great advice. your going to have to overbore it anyway. why not go bigger?
If you just cant swing it. I see no advantage with the ls2 internals vs the ly6 internals other then flat top pistons. simply milling your heads a bit will do the same thing.
good luck either way you go.
bpatrol

compression going from 9.6 to 10.9 would be the benefit. and also, do you have a source for the concept of boring the block .065 over reliably? that REALLY seems excessive to me, I want 100% reliability.

100 percent reliability doesnt exist in motors. you always balance the benefit with the risk. I do not have a source but i recall seeing motors bored to this. do search with lq4's the blocks are the same and have been around longer and should yield you some answers. also you could just go .030 over too right?:).
and you could mill to achieve the same compression ratio.
good luck
bpatrol

100 percent reliability doesnt exist in motors. you always balance the benefit with the risk. I do not have a source but i recall seeing motors bored to this. do search with lq4's the blocks are the same and have been around longer and should yield you some answers. also you could just go .030 over too right?:).
and you could mill to achieve the same compression ratio.
good luck
bpatrol

I could go .030 over, but then I'd have to get .030 over pistons, instead of stock ls2 pistons, which are much much cheaper. which is the point here, make power, reliably, don't spend money. break the trifecta rule. I like breaking rules.

The LY6 is an iron block and easily capable of an .065 bore & hone. When people can get there hands on LY6 blocks they are sometimes used to build 416 strokers, take a look. Find a good shop that is local to you that has experience with these engines. The LS2 piston will not yield 10.9:1 compression with L92 heads. If you want maximum performance AND reliability on a budget I would recommend an bored & honed block using torque plates, new piston rings, new bearings, and upgraded rod bolts. Using stock pistons is fine and obviously more economical and they're very durable IF you're paying attention. My objection to LS2 internals come from the fact that you will most likely be unable to use them in the block if you hone the block. You need to hone the block for rings to seal. Do people swap them? Yes, but it's not ideal from a performance or reliability standpoint. I wanted to do the same thing but when you measure the bore then account for the couple thou needed to clean the bore up you end up with excessive piston to cylinder wall clearance.

Sorry mai Kris! I need to get my head out of my ass I keep confusing this ly6 with the l76.

Yes it is iron BUT boring it to 4.065 will need to be worked on by a shop knowing what they are doing of course. Contact AES they do these alot and they can also get you your stock parts that you need.

Sorry mai Kris! I need to get my head out of my ass I keep confusing this ly6 with the l76.

Yes it is iron BUT boring it to 4.065 will need to be worked on by a shop knowing what they are doing of course. Contact AES they do these alot and they can also get you your stock parts that you need.

Would I sacrifice reliability for that? I don't really sacrifice any by using ls2 shit, and I don't want to flush peace of mind for an extra .2L of displacement.

also, know of any shops in Al, maybe around Birmingham, that would be competent enough to do this? most of the shops in Montgomery tend to be really old school sbc guys, so I'm not 100% on whether they could do it properly. There's not a whole lot of money down here, so there isn't much market for fast motors, and therefore no real speed shops to speak of