INSOMNIAC

Anybody building a 402 Forged motor using a LS2 block which comes with 4.000 bore from GM and LS1/LS6 Rotating Assembly?

I want to have a forged 402 for a twin-turbo or supercharger application but would not use a sleeved LS1/LS6 block for FI. The LQ9 iron block is 80 lbs heavier than the stock LS1/LS6 block. The LS2 block becomes a nice alternative to build a no-sleeve aluminum 402.

LS2 block goes for $995.00 now which makes it a good deal compared to sleeved LS1/LS6 or the 80 lbs heavier LQ9 Iron block.

As far as I know, the parts that need to be changed are
- Cam sprocket
- Front cover
- Cam sensor
- Knock sensors
- LS2 timing chain

I would love to see how a forged low compression LS2 402 with LS1/LS6 rotating assembly works under 10-16 lbs of boost.

Bill Reid

We'll be building 6L (364CI) LS2 motor after Christmas for one of our customers with a Stage1 TTi kit. We'll be using a stock 3.622" stroke crank, Eagle Rods, JE Pistons and more than likely one of Road Rebel's turbo grind cams. We'll then put his LPE Stage2 ported 6L (LQ9 317 casting) heads on top of this shortblock. Should be real nice when its done. Of course we'll share the results...

A 4" crank in the LS2 block should not be a problem at all... definitely need the StageX kit for the bigger cubes.

Yes, you will need:
LS2 Cam Sprocket
LS2 Front Timing Cover
LS2 Cam Sensor
LS2 Valley Cover

Your old knock sensors can be reused. There are unused bosses on either side of the LS2 block that can be drilled, tapped, and helicoiled to facilitate the old knock sensors. LS2 knock sensors are not compatible with LS1/LS6 harness/PCM.

BigLew

TTT for you, I would like to know as well

INSOMNIAC

Bill,

Are you building the LS2 short block for a C5 or C6? Is it going to be FI or NA?

I've heard that the knock sensors are "The Problem". If you use LS2 knock sensors, it's direct fit but they will be non-operational and you will be running the engine without knock sensors which I don't think is a good idea. I don't know how to make the LS1/LS6 knock sensors work with the LS2 block cause they are totally different.

Also, would the stock LS2 Timing chain be strong enough to handle a twin-turbo or supercharged 750 RWHP engine? Wouldn't I need Double Roller Timing Chain for high HP applications?

Here are couple pictures of the new LS2 block. I thought it might help to actually see it.






And here is LS1 Timing Chain vs LS2 Timing Chain

Bill Reid

The LS2 we'll be building will go in an 01 Coupe... that already has the TTi Stage1 Twin Turbo kit.

As I said earlier the LS2 knock sensors are incompatible with an LS1/LS6 C5. The old sensors are screwed into the sides of the block after drilling, tapping, and installing a helicoil in an existing and unused boss. The LS2 sensors are a 2 wire setup... the LS1 sensors are a 1 wire setup. Andy over at A&A has already been through this process... and he has been gracious enough to share the information with everybody. I believe there was a big discussion awhile back in the C6 section of this forum where Andy posted alot of what he learned regarding the C6/LS2... when installing a C5R block in a C6 and the need to utilize the C6 knock sensors adapting them to the C5R block. Stuffing an LS2 in an LS1 based car is essentially the reverse process.

The LS2 timing chain looks almost the same as the Katech chain we normally use. To date we have not seen or heard of this chain stretching or breaking. A double roller is a great setup... no doubt... and not a bad idea to go with when you are talking 750rwhp. We have seen some interference problems with a double roller chain actually riding on the stock crank snout hub on the back side. We have seen this on both the 01-up LS1/LS6 block and the 6L iron block with stock cranks. I just talked with Andy and he hasn't had a problem with the double rollers so perhaps there are or were some intermittant quality control issues (or spec range fluke) with either GM, Rollmaster, or both concerning the tight clearances between the chain and crank hub.

Nice pics of the 6L block... got one sitting on our shop floor now. If you look at your pic you can tell the significant difference in the valley... which also necessitates the use of an LS2 valley cover (no knock sensor holes).

NICK YOSKIN

will oil pan work, different on c6

INSOMNIAC

Bill,

The LS2 doesn't have the knock sensor bosses cast in the valley like an LS1 block does. If you thread too deep, you'll hit the cam I guess? I would love to see the picture of fitting LS1/LS6 knock sensors in a LS2 block.

How about the oil pan? Does the stock LS1/LS6 oil pan work with the LS2 block? I know the LS2 oil pan is different than LS1/LS6 oil pan. Alternator, water pump, etc. They are all interchangable right?

How much can you bore these LS2 blocks beyond the stock 4.000 bore?

Thanks.

BLOWNZO6

You know.. no offense but are you even reading what Bill is posting before you ask another question?

In both of your posts you ask questions about items he has already covered.

Read through what the guy is posting before you post another question.

INSOMNIAC

None taken. Yes, I'm reading all the posts but I just wanted to fully understand the whole thing with the knock sensors. I'm just having a hard time visualizing it. If you know how to fit LS1/LS6 knock sensors in a LS2 and make it work, please be my instructor and show it to me.

Nothing about boring the LS2 block beyond 4.000 bore was mentioned in the previous posts so I asked.

Are there any other redundancies you would like to point out?

BLOWNZO6

Well .. since you asked..

In his post it clearly states that the LS2 SENSORS ARE NOT COMPATIBLE but there are holes IN THE SIDE OF THE BLOCK TO MOUNT THE LS1 SENSORS IN.

Then you asked both of these questions again, immediately after, and also if you drilled to far in would you hit the cam.. implying you though the sensor holes needed to be tapped in the valley, please refer to previous post. Then about the oil pan.. someone already asked... sorry just giving you a hard time...

Since I am an

Z06GMAN

He is just because his wife is going to beat him

MiamiDave

Be a sale right here if you could button the whole lower half together to bolt up to existing LS1 computer/knock sensors, with forged internals, low or high compression pistons-oh, and make it 403 cubic inches!

Oh, and by the way, $3500.00 for the first 10 forum members

Bill Reid

To my knowledge the C5 oil pan, alternator/power steering bracket, and water pump will work on an LS2 block.

I have heard that the LS2 block, just like the LS1/LS6 block, is only capable of a service bore... meaning perhaps a 0.005 or 0.010 over to "clean up" a cylinder. So, suffice it to say I wouldn't make a decision on boring an LS2 block until more information regarding its servicability is published or at least communicated more mainstream. For forced induction I would recommend against boring at all... at least on an aluminum block.

Bill

INSOMNIAC

Bill,

I have couple questions regarding the TTI Stage X kit. I would appreciate it if you could answer these.

* Are the Turbos offered in Stage X kit Turbonetics T3/T4 Super Series Hybrid Turbos? Are these T3/T4B or T3/T4E or T3/T4R? Are these the "Ceramic Ball Bearing" Turbos? Can we get the Turbos with Polished Compressor Housing and Ceramic Turbine Housing? Are the turbos water cooled?

* Do the Stage X manifolds have T3 or T4 flanges?

* Can we get the T3/T4 Hybrid Turbos with "TUFF-TURBO" option? "The “TUFF-TURBO” option is available for all T4 series, 60-1, and 62-1 turbochargers. This TURBONETICS exclusive option utilizes O, P, or Q trim turbine wheel shafts, and the “stagger gap” piston ring. Specially developed for competition applications, the “TUFF TURBO” option includes the “big shaft” with a larger bearing structure, larger thrust bearing and a left-handed nut. The “big shaft” virtually eliminates the destructive shaft motion normally associated with high boost. The “TUFF-TURBO” option is available with dynamic seal only."

* Can I fit Turbonetics T-62-1 or T-66-1 or even better T-68-1 Ceramic Ball Bearing Turbos to these manifolds?

* Can I fit Garrett GT-35R or Garrett GT-42R Dual Ball Bearing Turbos to the TTI Stage X manifolds?

Thanks

BLKTA

Bill - Thanks for the info. Have you tested to see if the LS1 knock sensors actually work and pick up knock retard?

Bill Reid

INSOMNIAC,
Yes, the TTi StageX kit comes with Turbonetics T3/T4 hybrid turbo's that can be optioned with or without ceramic ballbearings. Beyond that I'm not at liberty to discuss specifics of the turbo's. Yes, you can get polished compressor housings... but why? You can't hardly see the turbo from up above. Yes, you can option the turbine housing to be ceramic coated... either bright silver or flat black. As a note ALL ducting and down pipes are ceramic coated. I am not sure if the cartridges have a coolant circuit option. I thought they did but I'll ask. The StageX kit manifolds have a T3 flange. I do not know if the "Tuff-Turbo" option is available on the T3/T4 frame... Turbonetics does not advertise the option to be available on the T3/T4 but it never hurts to ask Regarding the fitment of larger turbo's I just don't know. I wouldn't think a physically larger turbo is an option due to location space constraints. So, the answer to your last 2 questions, in my opinion, is no.

BLKTA, no we have not tested the LS1/LS6 knock sensors on LS2 block as we do not yet have a running example... but I am very confident that the LS1/LS6 knock sensors will have absolutely no problem picking up knock frequency. If you think about it the knock sensor is nothing more than a microphone. Although the sensors proximity and positioning to the cylinder banks is important, cast aluminum, and cast iron for that matter, are excellant conduits for transferring frequencies in the specific spectrum range at which knock noise is monitored. Sensitivity as it relates to the change in proximity to the event may or may not be an issue... but I'm leaning at this point to it not being an issue. I guess we'll just have to wait and see

Bill

Z06GMAN

Man Bill working on T-day...whats wrong with you .......and I LIKE it alot

Bill Reid

I figured I'd post on a thread or 2 before I start drinkin'

Happy Thanksgiving

chuntington101

i dont mean to pea on anyones bonfire, but i think SLP have a 402 strocker for the LS1 that is a straight drop in (no block mods). they offera high or low comp version. also sell a short block i think.

anyway have a look. www.slponline.com

thanks Chris.

BLOWNZO6

It is an iron block.