Frankenstein partial lsj/l61 supercharged cavalier questions - Boost Forum

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Frankenstein partial lsj/l61 supercharged cavalier questions
Thursday, November 06, 2008 10:50 PM
I know people have asked in the past about an L61 to LSJ swap on 03-05 Cavaliers and the complications, but my question refers to a partial swap. It revolves around mantaining the original Cavalier PCM. Now I know that some of the issues with the swap include its coil-on-plug ignition, the harness, transmission, fuel rail (not to sure, if someone could elaborate on this issue) and fuel delivery, intercooler, engine mounts, and others I can't think of right now.

Well here is the thing, I have a 2003 Cavalier with an L61 at 104,144 miles and have been planning on doing a performance rebuild on the engine. Then I thought about the swap and pondered further. Since the LSJ block is stronger and built for forced induction, instead of building up a beat up L61 (I would rather start with a brand new race prep GM L61 block) by boring it, putting new sleeves, pistons, rods, head, etc. couldn't one just:
1.) take an LSJ engine (oil pan, block, head, header, intake monifold, s/c) from the junkyard,
2.) installed the L61 valve cover (since the the bolts for the middle cover, or CDI in the L61, are different), so one can put on the L61 CDI,
3.) connect the L61 harness to the sensors on the LSJ block,
4.) maintain the (in my case) automatic transmission from the L61 and bolt it on to the LSJ (I'm not sure on the bolt pattern, though, but I am pretty sure they would be the same since it is the same basic block),
5.) install an aftermarket fuel pump (or maybe even the LSJ fuel pump),
6.) take the resovoir, aftercooler and pump from the LSJ and adapted it to the Cavalier like bolting on an intercooler,
7.) if the lower mount and/or oil pan is different then excahnge the LSJ with L61 oil pan and lower bracket,
8.) and take the Cavalier to a GM dealer and have them reprogram the PCM for the GM Cavlaier/Sunfire Supercharger Kit #17800003 (although that reprogram is for 8 psi or boost not the LSJ 12 psi, maybe slip the tech a 20 to boost up the fuel table).

I would get a stronger block, higher flowing stronger head, 12 psi S/C with the easy-ness and stock-like, medium difficulty, swap. Not just that, but couldn't one use the stage kits for the S/C LSJ and upgrade the pulley, 2-pass intercooler, injectors, etc.

If anyone can tell me why this might not work or if I have forgotten any issues, let me know, because this swap would only cost me no more than 3k with an extra 5spd tranny laying around for sale to recouperate some of my money.

Re: Frankenstein partial lsj/l61 supercharged cavalier questions
Friday, November 07, 2008 2:58 AM
The L61 block is fine for boost. Its the rods that give way first. You don't have a bad idea, its just that its not really gonna work quite the way you want or mentioned. First problem being that the cranks are different, well the reluctor rings are. The fuel rail im pretty sure is a return-less style system with no FPR built into it. It's actually in the tank. And the GM reflash doesn't work like that. Its not designed for 8PSI. Its designed to read boost to a limit. I have a stock pulley on my cav's kit and I see 10-11 PSI every day.

All the aftercooler stuff doesn't just come on the cobalt, you have to buy it aftermarket.

Do you already have this lsj block?
Re: Frankenstein partial lsj/l61 supercharged cavalier questions
Friday, November 07, 2008 10:01 AM
I feel dumb, but what are the reluctor rings? It is starting to seem silly, but like most of us, I'm on a budget and it would be easier to convince my wife into buying a block for $2200 than a S/C for $2500, plus any other modifications to the engine to create more power. I don't have the block, but I found two, one at 2200 and the other at 2500. Also the Cobalt SS S/C does come with an aftercooler system from the factory.
Re: Frankenstein partial lsj/l61 supercharged cavalier questions
Friday, November 07, 2008 1:17 PM
A reluctor ring is a ring with "teeth" on it. It is on the crankshaft. There is a crank sensor, which is really just a magnetic pick up that figures out where each piston is and what stroke it is on, that sits above it. They are a world apart between a L61 and Lsj. You won't be able to run the engine with the wrong reluctor ring.

I coulda sworn they didn't come with the aftercooler setup. I know the manifold comes aftercooler ready, with a core inside it and two tubes coming off it for the coolant.

Something else I just remebered. Cobalts have a Mass Airflow Sensor. Cavaliers do not.


Read this thread-

http://www.j-body.org/forums/read.php?f=2&i=411449&t=411449

In all honesty, save your money, buy a used L61 with less milage, get some good rods and pistons, and drop it in with the s/c kit, and you are set.

Another thing before it comes up, I will give you some advice, don't try and piece the s/c kit together. It is a giant headache and you need an ass load of items. It is just easier and maybe even cheaper to get the kit.
I know from my own personal experience.
Re: Frankenstein partial lsj/l61 supercharged cavalier questions
Saturday, November 08, 2008 2:26 PM
Yeah, I've looked into it some more and with all your advice I think it's best if I just stick to building up my L61. I might go turbo for now till the engine blows and get a new race prep block then. Well thanks for all the help and I'll see how my turbo idea goes (any tips or advice for turboing my stock block would be greatly appereciated). And yes, S/C kit is the way to go than custom.
Re: Frankenstein partial lsj/l61 supercharged cavalier questions
Saturday, November 08, 2008 6:44 PM
http://www.j-body.org/forums/read.php?f=40&i=56976&t=56976. Here is a basic parts list. You can also look at http://www.turbosystem.com/auto/Cavalier/ecotecplatform.htm if you decide to swap to a manual tranny.
Re: Frankenstein partial lsj/l61 supercharged cavalier questions
Tuesday, April 13, 2010 8:30 AM

On my 02 cavay I am swapping an 2200 out and putting in a L61 block LSJ head, intake and supercharger.

You will have to swapp LSJ oil pan to cavalier 2.2L ecotec oil pan. The cavalier L61 ecotec has mounting holes on the oil pan to mount the bracket for the lower engine mount. Cavalier, Ion and Saab LSJ oil pans are completely different.

L61 cam cover will not mount on to an LSJ head. Have to use the LSJ cam cover. LSJ head will go on a L61 block, but you have to use a L61 harness and PCM. My firewall harness connector is a direct match to the ecotec engine harness; wire for wire. LSJ engine has a few extra sensors that are not used on the L61, like cam position sensor. Which left on the head, but will not be connected to any electrical; using it as as a plug.

LSJ manual trans will bolt to a L61 block. But will not bolt up to the cavalier transmission mount locations. The mounts are in different positions; even attempted to switch brackets and mounts. I even looked at swapping the LSJ manual trans internals to F23 manual trans; that is a no go either. I have not seen auto, but I doubt that it will mount either.
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