View Full Version : Why 2.0 instead of 2.4?


Kazuki
04-23-2008, 12:34 PM
Just out of curiosity, since I'm still new to the racing world, why did chevy decide to use the 2.0 litre and supercharge that, instead of super charging the 2.4? The 2.4 is what, 171hp stock?? and The SS/SC is 206 hp stock?? We're only 30'ish hp behind. And isnt like the turbo'ed or SC 2.4's faster than the 2.0's? I dunno, I might be wrong, but if anyone can make this clear for me, it would be appreciated! Thanks guys.

Jimmys2007CobaltSS/C
04-23-2008, 06:34 PM
dont know but alot of stock ss/sc dyno 215-220 whp and the 2.4 ss are about 145-150 whp stock

Psykostevo
04-23-2008, 06:37 PM
The reason they picked the 2.0L was because of shorter stroke to compliment the characteristics of the eaton. But then why not build a bigger charger and use the bigger motor.

blissmaster13
04-23-2008, 06:39 PM
I think it has something to do with emissions. I'm not positive but I thought I read something about that a long time ago. I could be completely wrong though.

xxsportscar
04-23-2008, 07:15 PM
go and read scca racing rules, the cut off for many of the lower classes for a fourced induction motor is 2.0L, so a 2.4 supercharged moves into a different class where it would be less competitive, im amost certin that the decision to use a 2.0 insted of a 2.4 was made largley for that reason. along with the realization that they could make acceptable power out of the 2.0

i may however be wrong but thats my hunch

DARIN616
04-23-2008, 07:16 PM
yeah i bet its emissions, its always emissions

Acey
04-23-2008, 07:20 PM
But hold up, didn't the LSJ get phased out because of emissions anyway? So they didn't do a very good job. :lol:

I'm assuming the LNF is better, but I don't know how much better it could possibly be.

GULLABLE0NE
04-23-2008, 07:25 PM
But hold up, didn't the LSJ get phased out because of emissions anyway? So they didn't do a very good job. :lol:

I'm assuming the LNF is better, but I don't know how much better it could possibly be.

the ss/sc didnt pass the NEW emissions. in 2005 when it started production it was fine, i think something changed in congress that affected the emissions standards.

I guess dodge wasnt scared to put the srt4s into a different class. way to grab it by the horns with the skittles

i also think the supercharged montes had the emission issue and thats why they discontinued that model ( i could be wrong)

Acey
04-23-2008, 07:26 PM
^^ Sooo if they built up and SC'd the LE5 it would be in a higher class and thus have less strict emissions?

GULLABLE0NE
04-23-2008, 07:29 PM
no i think that wold just put it n a different class for some racing organization. i believe the emissions rule stands for 4 cylinder cars no matter the displacement.

Projekt
04-23-2008, 07:31 PM
less displacement means more air into the cylinders or something along those lines...notice why ALOT of forced induction stock cars are 2.0L or lower..

its something like that..more boost or something..

BlackCherryZ28
04-23-2008, 07:35 PM
I thought that GM needed an ecotec with a forged bottom end and they already had a 2.0 forged ecotec motor they were using in the Saab

Yellow08
04-23-2008, 09:42 PM
I would imagine that the 2.0 is lower compression than the 2.4. A N/A engine normally has higher compression that a forced induction engine.

Turbo06Sedan
04-23-2008, 09:56 PM
*prepares to piss off the 2.0 owners*

Meh..who cares...2.0's suck.

mike25
04-23-2008, 09:57 PM
because it was less of a hassle to boost that specific motor...it doesnt have the potential a 2.4 block does..but hey gm is known for taking the easy route

riko540
04-23-2008, 09:57 PM
oh boy here we go :lol:

2WILD4U
04-23-2008, 10:23 PM
it is because the 2.0 has better compression than the 2.4. that is what i think.

InfinityzeN
04-23-2008, 10:45 PM
Because when the LSJ came out, there was no 2.4L engine. LSJ predates it by a couple of years (LSJ=2003, LE5=2005). Kinda hard to build a S/Ced version of the LE5 when it won't be out for 2 years.

/Thread

Evil C
04-24-2008, 12:26 PM
Well my money is on either its a stronger block or they had a bunch of 2.0s lyin around. Just be greatful its not a late 70- early 80's a/g body. They had almost no rime or reason to what they got and had 3 or 4 v6's and 3 or 4 v8's and weird ones i had one originally equipped with a 3.3l v6 and another one with a 307 SBO (which is garbage despite factory roller rockers)

mike25
04-24-2008, 03:14 PM
Well my money is on either its a stronger block or they had a bunch of 2.0s lyin around. Just be greatful its not a late 70- early 80's a/g body. They had almost no rime or reason to what they got and had 3 or 4 v6's and 3 or 4 v8's and weird ones i had one originally equipped with a 3.3l v6 and another one with a 307 SBO (which is garbage despite factory roller rockers)

the 2.4 has the stronger block...the 2.0 is just a debored version of the 2.2 with some performance inernals and a boost setup with different tuning.....not to mention the 2.4 has vvt

shabodah
04-24-2008, 03:26 PM
There is a lot of ignorance in this thread.

As already stated, the LSJ predates the LE5 and it was basically already in production for other GM models. Sure, the LE5 block is newer and thus, more revised and slightly stronger, and sure, it has VVT, but in the long run, those things don't make much of a difference.

Considering the fact that the LE5 crank and rods are weaker than the LSJ's, and it uses standard valves instead of the sodium filled exhaust valves the LSJ uses, and does not have the oil injectors the LSJ has, nor the larger oil pan, it really ends up becoming a wash.

Regardless which of the two you have, your best bet is to rebuild it with some components of the other for the best reliability and horsepower.

However, the LNF block is superior to both, so, again, this becomes somewhat moot. If better pistons were available and tuning was available, it wouldn't even be a question, the LNF would be superior in EVERY way.

That said, it seems to me that a 2.4L engine when boosted is going to make more torque than a 2.0L engine, and because the .4L difference is almost all stroke, this puts more demand on the rods (which are already a weak spot), it makes little sense to stick with the 2.4L crank. Torque steer and wheel hop are already a huge issue.

Thus, I'd recommend (much like MVP already has built), a combination of the LE5 shortblock and LSJ head. This can be improved by adding titanium intake valves, jesel rockers (roller followers, techinically), and a dry sump system. At that point, regardless of what block you have, the sleeves and rods are the weak components (assuming pistons are already done because they should be done FIRST on either).

mike25
04-24-2008, 03:33 PM
There is a lot of ignorance in this thread.

As already stated, the LSJ predates the LE5 and it was basically already in production for other GM models. Sure, the LE5 block is newer and thus, more revised and slightly stronger, and sure, it has VVT, but in the long run, those things don't make much of a difference.

Considering the fact that the LE5 crank and rods are weaker than the LSJ's, and it uses standard valves instead of the sodium filled exhaust valves the LSJ uses, and does not have the oil injectors the LSJ has, nor the larger oil pan, it really ends up becoming a wash.

Regardless which of the two you have, your best bet is to rebuild it with some components of the other for the best reliability and horsepower.

However, the LNF block is superior to both, so, again, this becomes somewhat moot. If better pistons were available and tuning was available, it wouldn't even be a question, the LNF would be superior in EVERY way.

That said, it seems to me that a 2.4L engine when boosted is going to make more torque than a 2.0L engine, and because the .4L difference is almost all stroke, this puts more demand on the rods (which are already a weak spot), it makes little sense to stick with the 2.4L crank. Torque steer and wheel hop are already a huge issue.

Thus, I'd recommend (much like MVP already has built), a combination of the LE5 shortblock and LSJ head. This can be improved by adding titanium intake valves, jesel rockers (roller followers, techinically), and a dry sump system. At that point, regardless of what block you have, the sleeves and rods are the weak components (assuming pistons are already done because they should be done FIRST on either).

i was not saying the LE5 is superior for having vvt...im saying its somewhat a hold back...but anyways im not sure what your referring to with the oil injectors but if your talking about the oil jets for the bottom side of the pistons the le5 has them too....the le5 also uses updated rods iirc similar to the lsj's...the only really difference is the pistons and a few other small things....as for the rods i would upgrade them anyways

OrngBalt
04-24-2008, 03:34 PM
Because when the LSJ came out, there was no 2.4L engine. LSJ predates it by a couple of years (LSJ=2003, LE5=2005). Kinda hard to build a S/Ced version of the LE5 when it won't be out for 2 years.

/Thread

I think we have a winner here... remember when the cobalts came out they were 2.2's and then they introduce the S/C with a 2.0 all the sudden whp was 215-220 compared to 115-120.

then the next year they introduced the SS/NA and obviously for it to be considered an SS it had to have more power, but they didnt want to supercharge so the only way to do that..... Bigger engine with better tuning. TA DA!!

if the SS came out before the SC... we would likely have SS/SC 2.4's but it didnt work that way

shabodah
04-24-2008, 03:43 PM
i was not saying the LE5 is superior for having vvt...im saying its somewhat a hold back...but anyways im not sure what your referring to with the oil injectors but if your talking about the oil jets for the bottom side of the pistons the le5 has them too....the le5 also uses updated rods iirc similar to the lsj's...the only really difference is the pistons and a few other small things....as for the rods i would upgrade them anyways

The LE5 rod is better than the L61 rod, no doubt, but a longer rod with a shorter stroke will always be stronger just for the sheer physics of things (rod angles mostly). The LE5 has provisions for the oil jets, but it was my understanding, that it doesn't actually have them. Can someone confirm this? Regardless, With the power both are capably of, the expensive part is figuring out who can put a good set of sleeves in your block and do it right.

Lack VVT is one of the reasons why the LSJ could not meet this year's emissions, but, from a performance perspective, especially on a supercharged engine, it is really not holding the engine back. NONE of the drag cars are using VVT, afterall.

mike25
04-24-2008, 03:55 PM
The LE5 rod is better than the L61 rod, no doubt, but a longer rod with a shorter stroke will always be stronger just for the sheer physics of things (rod angles mostly). The LE5 has provisions for the oil jets, but it was my understanding, that it doesn't actually have them. Can someone confirm this? Regardless, With the power both are capably of, the expensive part is figuring out who can put a good set of sleeves in your block and do it right.

Lack VVT is one of the reasons why the LSJ could not meet this year's emissions, but, from a performance perspective, especially on a supercharged engine, it is really not holding the engine back. NONE of the drag cars are using VVT, afterall.

ive heard multiple times it does have the oil jets...and i myself am almost positive it does...i should have clarified when i said the vvt holds things back...it holds things back more on a tuning level than anything...at least to the general public...sleeves shouldnt be too hard to come across

shabodah
04-24-2008, 03:57 PM
sleeves shouldnt be too hard to come across

I know of lots of places to buy sleeves, but very few who will install them.

mike25
04-24-2008, 04:08 PM
I know of lots of places to buy sleeves, but very few who will install them.

with the proper know how..one could do it themselves

shabodah
04-24-2008, 04:10 PM
with the proper know how..one could do it themselves

Actually, I know how to do it, but I don't trust myself to.

mike25
04-24-2008, 04:12 PM
Actually, I know how to do it, but I don't trust myself to.

yea...that would be my case also

BlackBaltSSNA
04-24-2008, 08:38 PM
Isnt the LNF coming with vvt due to the emissions thing?

shabodah
04-25-2008, 08:46 AM
Isnt the LNF coming with vvt due to the emissions thing?

The LNF has VVT and can spray fuel into the exhaust to light-off the cat quicker (one benefit of DI), both reducing emissions.

Dead Zen
04-25-2008, 08:50 AM
so what about 2.0 liter cars having a perfect square design? all boosted mitsu motors (4g63) nissans sr20det

Kazuki
04-25-2008, 02:04 PM
Sooo, if GM were to spend some money upgrading the 2.4l rods and pistons and spend the same amount of money into the 2.4 as they did for the 2.0, the 2.4ls would actually be better correct?

WSFrazier
04-25-2008, 02:09 PM
less displacement means more air into the cylinders or something along those lines...notice why ALOT of forced induction stock cars are 2.0L or lower..

its something like that..more boost or something..

http://img292.imageshack.us/img292/5481/lolwutsp3.jpg

originaladrian
04-25-2008, 02:11 PM
http://img292.imageshack.us/img292/5481/lolwutsp3.jpg

OMG LMAO :lol::lol::lol:

shabodah
04-25-2008, 02:14 PM
so what about 2.0 liter cars having a perfect square design? all boosted mitsu motors (4g63) nissans sr20det

Oversquare motors do just as well. Perfectly "square" doesn't net you anything more than just over or just under has.

The 2.4L engine could have been upgraded, sure. Heck, the LSJ and LNF are more similiar to both SRT-4 motors than people would believe, and well, since the new SRT-4 motor is extremely similiar to the new Evo motor, well, there are more similiarities than differences.

06blackg85ss
04-25-2008, 02:16 PM
lol wow this thread is terrible.
LSJ is a destroked version, 86mm bore x 86mm stroke. better for high rpm usage as in drag racing since they rev over 10krpm. you can't really do that with a long stroke motor without creating damaging crankshaft harmonics and all other types of bad crap.
There's more, but I really don't feel like going through it, though a built up 2.4 litre bottom end with an LSJ head probably would make some rediculous power with a turbo setup, too bad the one guy with that setup sold the car, or is

Witt
04-25-2008, 02:16 PM
Just out of curiosity, since I'm still new to the racing world, why did chevy decide to use the 2.0 litre and supercharge that, instead of super charging the 2.4? The 2.4 is what, 171hp stock?? and The SS/SC is 206 hp stock?? We're only 30'ish hp behind. And isnt like the turbo'ed or SC 2.4's faster than the 2.0's? I dunno, I might be wrong, but if anyone can make this clear for me, it would be appreciated! Thanks guys.

It was destroked to increase top end horsepower and lower piston speed for a higher redline and less wear on the engine.

shabodah
04-25-2008, 02:20 PM
To restate things in a different way:

The LSJ was two liters with a short stroke because GM was still unsure on its exact durability and didn't want a lot of warranty claims.

The LS9 is 638 horses for the same reason.