I know i have seen the discussions b4, couldn't find it in a search. What all was done to utilize the longer stroke of the LE5 crank in the LSJ block? Were there custom rods needed or do stock dimension lsj's work, and what type or CR's would this produce?
Like I said I couldn't find the thread that this was discussed b4, so maybe someone could post it if they know off hand. t/y ia

 

custom clutch, rods, pistons and clearancing of the block just to start.

 

flywheel is different you need to shim the crank position sensor so it dosent hit the relucter and you need to swap out the relucter the 2.4 is different then the 2.0

 

ZZP says you can use their 2.4L fidanza fly wheel with most aftermarket clutches.

Cobalt & Ion ---> ZZ Performance

You can shim out the crank position sensor or replace the "teeth thingy" on the LE5 crank with one from the LSJ.

Stock LSJ pistons and rods will work fine. But aftermarket ones will allow more power. Unless you are running E85, I would leave the CR alone. I am not sure what kind of effect on CR using the LE5 crank would have...

Its actually a lot easier then people make it out to be...

 

if you use stock length rods with a longer crank throw you will push the piston directly into the head so expect to have to run le5 rods if not actual custom ones.. you may well be able to use lsj pistons but expect to have to make many changes. cr changes if you dont use dished pistons because your trying to crush more air into exactly the same amount of space as before. compression ratio is a simple ratio of space from BDC to TDC vs combustion chamber space. since your increasing the BDC to TDC you need dished pistons to keep the compression ratio from rising to a point where boost becomes impractical. so just to start, custom flywheel and sensor hookup, custom clutch, the 2.4 crank, custom rods and pistons then a shop capable of clearancing the block if needed. Then of course the cam has to be stepped up to provide the lift and duration needed to feed the bigger displacement. A radical cam for a 327 chevy is a cream puff in a 383 stroker, the same principle applies here. ZZP put a lot of work into getting it to come together correctly, doing it yourself is going to be an unpleasant process. be ready to screw it up in several expensive ways along the way.

 

GM 2.4L Ecotec 5.715" C to C

GM L850 2.2L Ecotec 5.767" C to C

gm 2.0 ecotec 5.709

i pulled a set of 2.2 crower billet connecting rods out of a lsj not to long ago

 

so rather than using dished pistons all the stock cr changes are done with slightly different length rods? interesting. so 2.4 crank, 2.0 rods, dished pistons and youve got yourself a rotating assy with a resonable cr for a boosted motor.

 

Not true. All Ecotec rods are all basically the same length as Senior Belvedere pointed out.

Some what true. If someone plans on running E85 or methanol injection, a bump in CR would be welcomed. GMs new 2.4L ecotecs have CR rated up to 11.4 compared to the original LE5s 10.4. Even Auto manufactures are figuring out that high CR is a good thing. The fuel used in today's cars is much better then the stuff used in the 70s-80s.

None of this is true.

ZZP has said that the Fidanza LE5 flywheel will work with most LSJ aftermarket clutches.

The head on the LSJ already out flows the head on the LE5. Although a ported head would improve the performance of the engine.

I am not trying to be a jerk or anything. I have seen posts like yours for years on these forums. Applying dated practices from old platforms does not always work.

Ecotec engine builds are not as difficult as everyone makes them out to be. The problem with most builds is that they get too complicated and overly expensive.

The Ecotec hybrid build I find most intriguing would be putting an LSJ crank in an LE5 block with an LSJ head.

2.0L = 86mm x 86mm - LSJ, LNF
2.2L = 86mm x 94.6mm - L61
2.4L = 88mm x 98mm - LE5

Hybrids

2.1L = 88mm x 86mm - LSJ crank in LE5 block
2.3L = 86mm x 98mm - LE5 crank in LSJ block

ZZP was running a 2.1L ecotec Hybrid at the CED meet this year.

 

@Ebristol, Thank you so much for the info you have provided. That is exactly what I was looking for and appreciate all the "debunking" of ill-informed enthusiasts.

@mrbelvedere, Thanks for backing up the info provided by ebristol.

 

actually they knew way back when performance started coming around that higher compressions make an engine more efficent thats why you used to be able to buy 100+ leaded octane from the pump but with the tree huggers and the goverment that has went away now with all alloy engines to disperse heat alot faster then iron you can run higher compression on todays junk fuel (e85 dosent count)

 

all of my past experience says if your planning on running a lot of boost a cr of 8.5:1 to 9:1 is best. if the 2.4 is just better, why arent the 2.4 guys making better power than we are? our m62 bolts rights up to it but its power output is considerably lower, particularly when you consider the 20% greater displacement. why arent the 2.4 guys bolting on our head, manifold and blower and making 340hp? 2.0 fully bolted expects 300 whp, why arent the 2.4 guys making 20% more than that? why are they making considerably less? their anything goes dyno sheets are awful. lets go a step further. the 2.4 liter standard cobalt isnt worth the metal its made out of. the non ss naturally aspirated drive train is available for chump change. why are we talking about bolting in the crank from one when we could just bolt in the entire motor, tranny and computer then transfer over our forced induction systems and tune them? I suspect the reason is because zzp has figured out things that we dont yet understand about this conversion. my own plan is to run sleeves with the max bore and the stroker crank then bolt up a much bigger blower like a mp90, something that can fill the increased space effectively. look at zzps own 2.4 motor number on the dyno sheet. 350 whp. then on their 2.0. 898 whp. there is clearly something more up with making power out of this motor than just tossing in a bigger crank. going from 350 to 383 requires a bigger cam, higher flowing heads and a little forces aspiration if you really want to feel a hp increase otherwise your hp can actually drop, sure youll gain torque from the longer stroke, but hp can suffer without a way to fill the cylinders. the principles of internal combustion piston engines have not changed in one hundred years. what was true for miller and offy in the twenties is true now with our lsjs.

 

Because they dont have the cam's. And a fully bolted on lsj will only make 280ish wheel. And as has been shown with the other hybrid motors, a 2.4 bottom end with a 2.2 head and stock l61 cams chokes out, so you are right about needing bigger cams. Its for 2 reasons, 1 more displacement, duh. 2, the 2.4 has a worse rod to stroke ratio, a high rod to stroke ratio makes the car act like it has a more aggressive cam because peak piston speed comes further along the downward stroke. With the LE5 you need more aggressive cam opening to get the same valve opening at peak piston speed.

 

the main reason why the 2.4 guys who bolt a blower arent making power is because they arent doing anything inside to handle alot of boost ie rods and pistons

 

Even though the 06-07 le5 has forged internals and has been shown to take 350 wheel.

 

well shown and living are 2 different things