Broke a rod bolt and damaged my block. 2006 LSJ. I have a 2007 2.2 block. My LSJ head is fine. I have a spare LSJ crank. I will need rods and pistons. Not looking for big hp numbers abound 300whp. I have a Harrop with a 3.1 pulley and 60lb injectors I’d like to use on the new build. Looking for durability for track road racing.
The stock LSJ on a stage 2 has given me thousands of great laps but everything breaks eventually. Can I use LSJ rods/pistons in the 2.2 block or is a different combo needed? I read somewhere the deck height on the 2.2 is taller by a small bit? I’d like a little more compression but not so I need race fuel or methanol.

I also have a Saab 2.0l turbo engine ..exact year unknown..is that block useable for an LSJ build? Any way to tell what year it may be? I believe its >2000..it's got an 8 bolt crank in it.

I see that ZZ Perf. has Gen 3 short blocks with DI pistons assembled..IM assuming direct injection is what DI means..as in LNF etc. Anyone try one of those for an LSJ build? May be my best best at this point.
Thanks for any help.

 

Pretty sure you can, as theyre both 86mm bore blocks and you have an lsj crank for the proper signal. Just get lsj rods and pistons

 

Can you swap the LSJ head onto the 2.2? I read you can't.

 

I thought Slowbalt2000 ran an LSJ head on his 2.2 at one point. I know the LAP 2.2 you couldn't because of VVT sensors. I think physically all the ports are the same (coolant oil) into the head between blocks.

 

You can, but I believe there are a few small things you have to watch for like a lack of oil cooler hook-ups and potentially a different height on the crank sensor mount (I know the 2.4L's have this).

If you're putting aftermarket pistons in it anyway, you might want to look into picking up a 2.4L block (preferably the later ones with the deck bracing). ZZP makes pistons specifically for LSJ crank/rods in a 2.4L block, giving you a 2.1L. Again, a lot of these blocks do not have the oil cooler ports machined open. It can be done, but it's something to be aware of. I have a 2.4L block in my garage that I probably won't end up using.

As far as the ZZP block with the LNF pistons; I know plenty of people have done it for LSJ's.

If you want an LSJ block, I have one that needs to be resleeved. MrBelvedere does resleeving. He might have cores, I dunno. He's on Facebook, as is JNR, who usually has a handful of used blocks for sale. I can provide profile links if you're interested.

I was always under the impression that they were essentially the same casting with the difference being that the early 2.2's didn't have the cam sensor on the exhaust cam.

Are the 2.2 VVT sensors any different than LNF sensors? Because you can still use an LNF block for an LSJ build.

 

I was meaning using the LSJ head on a LAP as you don't have the intake and exhaust VVT sensors. I'm not actually sure if they're the same or not, I believe they are as there was someone maybe JNR that found out the 2.4L DI NA cams were an upgrade do-able for the LNF (this was a few years ago, I'm a little foggy).

 

Thanks for the answers.I really just need a block to build. I have read the 2.2 deck is 4mm shorter than the LSJ...which is odd, considering the 2.2 has a longer stroke.

I can sleeve blocks as I have the GM tools and have done so in the past, but finding an LSJ block to sleeve isn't that easy..plus the sleeves are about $100/each..and if I could use my 2.2 block, it has only 10K miles so I'm pretty sure the bore quality will be fine.

I do have a Saab 2.0L but am not sure of the year. I could buy a 2004 Saab 2.0L engine with 88k from a local junk yard for $250..and hope the bores are OK..but....

I also have a friend with a 2008 Solstice take-out LNF that has 50k on it..for $350 but once again..am not sure if the block is the same as the LSJ.

I have no intention of going to the LNF or any other turbo setup...I really really REALLY like the power band of the LSJ even at "only" a stage 2 tune.It may not make the BIG numbers..but that flat band is killer.

On a road race track my Ecotec powered Atom2 is king of two seater cars. Even the Atom3s with the Honda motors are easy targets. Supercharged,turboed or not.

With 300whp in my car....even those Formula 1000s will be in my range..

 

I would also say the later 2.4 blocks. I was reading on this actually right before this was posted. It was a thread back in 06. At that time the LSJ did not work on the early 2.2 engines. I don't know if it was ever done on a later block.. Also if you aren't on a tight budget, Hahn shows to have new 2.0s, 2.2s, and 2.4s.

https://www.hahnracecraft.com/produc...uilt-for-boost

 

Does your Atom use a stock GM ECU?

You can use the Saab engine, there are a couple things about them that need changed or something like that. I don't know the specifics, but it's on this site.

You can use an LNF block with an LSJ head (just make sure you're using an LSJ crank - the reluctor wheel is different). My last engine build was an LNF block with LSJ internals. Only thing you'll need to do is plug the turbo oil drain.

But honestly, the powerband on a stock turbo LNF is pretty damn great and flat... even better when tuned. If you made the swap to an LNF turbo setup (you can do this with the LNF block and LSJ head), I doubt you'd be disappointed. It'll make 300WHP a lot easier than a S/C'd LSJ... and it'll have much more torque.

 

Again, thanks guys! My Atom uses a Brammo specific GM ECU with no vats.

I have a couple of turbo cars (2005 Focus ST 2871R making 325whp and a 2004 Mazdaspeed Miata with a FM 2560r making 240whp) and although they are quite exciting..I'm not 100% sold they are better than the very linear power delivery of the S/C for track use. I am amazed how I can pull out of corners and pull on other turbo equipped Atoms as the hit on the tires doesn't seem to be there. I know good tuning is the answer...BUT, and this is the BIG but...tuners in my area are terrible,or want nothing to do with a road race car.

True story: I had a "tuner" in central Ma dyno tune my stock LSJ with a Harrop setup. While there, I did find it odd he had two LSJ heads on his work bench with burnt/busted exhaust valves..but I was told they were "overheated" by the owners on the highway. Hmm.
While on the dyno,I asked why he was not monitoring EGTs and he told me that was "old school" and as long as the A/F ratio was correct..not to worry. I told him again, what I was doing with the car: road racing..NOT drag racing. I told him In the course of one lap,I run the car to a redline pull about 5 times. No problem he says. The car made about 305whp according to the charts he gave me. I told him the motor was stock. He said no problem.
I took the car to a test day at NHMS, and for 6 laps..I was the fastest open wheel car there...including some formula cars. Lap 7, the car nosed over hard going down the front straight as I braked into turn one. On the exit of 2B I stepped on the throttle to a sputtering engine and looked in the mirrors to see...HUGE smoke so thick you could not see anything! I limped to the trailer and pulled the plugs. Cyl #4 plug was destroyed. I had melted #4 piston. On teardown #4 cylinder was scored bad enough to need replacing. I sent the piston to Mahle: they said at least 5 minutes of >2500 degrees heat. I put the engine back together with forged pistons (2 new sleeves..#2 cyl was iffy) and went back to the stage 2 tune.
That was about 7 years ago and thousands of laps. This summer I had one of the connecting rod bolts fail. Totally out of the blue..one second fine..next..BOOM. I though I ran over something on track the car jumped so bad. Yes..I should have gone with better rods and bolts..but everyone said the stockers would be fine at that power level. They were, for quite a while. Abuse is abuse!

This time I'll do real good rods and pistons. Live and learn.

 

I want to say Area47 is out on the east coast, he would be a solid tuner for road racing. Not sure if he still does anything with the LSJ engines.

I'm assuming you have an EGT gauge installed now as well?

 

Okay. The reason that I asked about the ECU was just because you would be able to change how the crank sensor reads the crank with something aftermarket.

That is the beauty of a blower. The Grand-Am Road Racing series Cobalts did well with both engines and GM really focused on making a track car, so that's why that stock turbo does so well.

Either way. You can take an LNF block, remove all the internals, and put your LSJ internals in it. Do you run the stock oil cooler or have you upgraded to an air-to-oil? I only ask because there is a difference between the LNF and LSJ oil coolers, and part of that is mounting (one bolt is in a different location between the two).

He's in Kansas City. But he is definitely a solid tuner. Powell flew him to Toronto to tune a (iirc, supercharged) road racing Corvette about a decade ago or so. He does still tune LSJ's, but I believe it's only through the shop that he works for. Not sure he does the traveling tuner thing anymore, but money talks.

 

"I'm assuming you have an EGT gauge installed now as well?"

Yes...matter of fact, after the dyno session I had ordered a gauge kit but the Track test day came up before the gauge came in. Shame on me for jumping the gun..but I was scheduled to go to Monticello for a grudge match against a SRA Atom the next month and needed to get in some laps. Haste makes waste.

I run the stock oil cooler and have never seen oil temps ever rise above 250 on the hottest days, and just under 200 for coolant temps.

 

That's probably why I thought he was out east, I knew he had tuned Powell's Corvette and his Ion

 

I figured as much and given you knew the importance of the EGTs assumed it was something like that.

Those are pretty reasonable fluid temps for road racing, glad to see the Atom's have pretty solid cooling setups. What kind of IAT2s do you see?

 

My IATs with the stage 2 are in the 100-120 range after a 30 minute track session,at the end of the longest straight. I am running a triple pass front mounted cooler..it's basically a stack of 3 Derale coolers, with fans.

The engine cooling is by a dual pass Saldana radiator up front, and 1.5" aluminum cooling lines to the rear, so lots of surface area. While other are overheating..I'm out there cracking the whip.

I mostly run time trials with the car and have numerous FTDs to date and have a dozen class wins. (Super Unlimited)

When I tell people it is powered by a Cobalt engine..they chuckle..till I fill their mirrors and fly by. It really is a joy to drive.

I recently (this year during the C19 lockdown) built a car I call the MOTA..a FWD backwards Atom..but that's a story for another day... I believe it has the capability of being faster than my Atom....



This is a pic of Max..my Atom, taken earlier this year.




I have to run Basset steel wheels on the back because I break aluminum ones..even 3 piece billet wheels. G forces are brutal on them. That's Whiskey Hill Raceway..my home track. Heaven on Earth!

 

The stock unit does work well, probably helps that your car doesn't weight anything close to a Cobalt.

You can use either oil cooler (LNF or LSJ) on an LNF block, but you'll have to customize some things either way. Using the LSJ oil cooler will require you to drill and tap a mounting hole (this is what I did with mine), while using the LNF cooler will require you to change up your radiator hose routing, as the exit port directions are a bit different. The LNF cooler also doesn't have the thermostatic spacer plate (which is where I mount my aftermarket oil pressure sensor/gauge).

I have both in my garage (blocks and oil coolers ), in case you want pictures.

 

I believe I will go look at the Solstice LNF engine that has been offered to me. For $350 itis cheap enough and it does not sound like much to get it to work in my Atom as an LSJ. I think it's complete so it should still have the cooler on it. I have a crank and will buy rods/pistons.(good ones..)

My Atom weighs 1400lbs...and that really is what makes it special. Weight truly is the enemy of performance. Sure,you can make a heavy car fast..but it consumes so many parts, it always is expensive to run. I have never replaced my brake pads (front or rear) and front tires last for a full season and age out before wearing out.

About the only major part I have had to work on has been the engine, and if I had left it bone stock the car would still be super quick and reliable.

Thanks for all of your help!

 

To be honest, stock rods and pistons are fine for your power level - I ran stock pistons and rods up to 400whp on a turbo setup. I've never heard of a stock rod bolt failure like that - makes me wonder if they had been reused (they're TTY, fyi). But, if you have to buy rods anyway, ZZP's rods are a few grams lighter than stock LSJ rods.

 

It's not really about a power factor strength for my engine components ,it is about living at 6-7k rpms for thousands of laps. It's a strictly road racing car.


A1 rod bolt failure

Escape port

MMMM!!! 3rd Gen goodness!!

I had an A1 rod bolt failure on #4 connecting rod. Not torque to yield bolts..just crappy rod bolts. It broke right where the threads start. Metalurgist friend of mine said they were too brittle and he was amazed they lasted 6 years (and thousands of laps..) The A1 bolts came with the rods/pistons I bought as new never run take-outs from a GM race team. No wonder A1 went out of business. Too bad because everything else in the motor looked perfect (bearings/pistons etc ). It wasn't a loss of oil or overheat..it was a lousy $8 rod bolt. Grrr...

I decided to go with a new Gen.3 block and will do Molinar H beam rods/Diamond coated forged 10.5-1 pistons,new custom ported head/cams and have it all balanced by Lindskog In Boxboro.

Thanks for all the help!

 

L61 bare block is the same as the LSJ except for lack of piston oiler and oil cooler provisions. I've ran an LSJ head on an L61 block and now I'm running an L61 crank inside an LSJ block with LSJ head.