it probably been explained i couldn't find it on a search but why did GM go with the 2.0 over the 2.4 for the ss/sc i've heard it was for the compression but no proof to back that up i would think a 2.4L would push out a little more hp...

 

Because gm is retarded. A 2.4L LSJ would probably put out 280hp and like 260lbs of torque

 

if thats true that would have been a bad ass set up but i still think there had to be a reason behind it...i don't think GM would have missed something that huge....Maybe emissions???? anyone have any facts on this???

 

^^ thats not really true.

when you boost a motor displacement isnt nearly as big of a deal.
they destroked and went for lower compression specifically to allow the LSJ to make power with boost.

2.4 N/A compared to the 2.0 boosted LSJ is apples to oranges.

 

yea thats what i kinda figured but thats if your boosting the same amount in the 2.4 that you would in a 2.0 right???....so if they would have made that sc push out more in a 2.4 that would have had the same or more compression right???

 

A 2.4L LSJ would put out 30-40 more pounds of torque then the LSJ does bone stock. The more the displacement the better.

 

This is going to get ugly again...

First of all, the LE5 (2.4) motor wasn't even available first. The LSJ was readily going I believe in 05.

Second of all, if GM was going to boost a engine (saying if they had a 2.4 from the beginning), GM wouldn't have it be 10.4:1 compression...

Just like any other manufactuer that develops a stock car, they have to look at emissions and reliability for a long term which plays effect into warranty claims. I really don't want to get into why applying forced induction will change the emissions on a higher compressioned engine or how it can effect reliability...I would say research on your part.

One last thing, GM does not care about power #s. They aren't out to develop race cars for $20k.

 

Why are supercharged Cadillacs of a lower displacement than their n/a counterparts?

 

Because displacement doesn't matter when you're messing with forced induction.

 

thats the point.
a 2.4 LSJ doesnt exist...
2.0L LSJ does exist.

and the only fair way to compare a 2.4 to 2.0, would be if a 2.4 LSJ DID exist, exactly the same as the 2.0, but with just the larger displacement.
and since it doesnt....its moot.

 

Exactly. It's basically the same as asking "Why didn't GM put in a 3.0L?"

Doesn't exist, doesn't matter.

 

Exactly. Was just throwing that out there for the people that are asking the same of the Cobalt engines.

 

Gotcha.

 

I'm really looking into swapping in the 2.4L's 3.9" crank into my LSJ. How much work is it going to need? That's not sure yet but i'm pretty sure i could use the 2.4L's rods and a set of custom forged. Now the big question is how much clearancing does the LSJ block need to make the big stroke crank work.

Then why do eaton blown 4.6L modular's put down 450+rwtq and the 5.4L's put down close to 600? If you think displacement has no effect on power then you need to do some research.

 

Can I ask why?

That's how they set it up apparently.

The point being is that you can make any displacement engine put down whatever amount of power you want, it's just how you set it up. There are 500 HP 1.8L motors. Displacement isn't what you need to focus on if you have forced induction. If you were naturally aspirated, that would be a different story.

Edit: Don't put words in my mouth. I didn't say it DOESN'T effect power increases, I'm saying it shouldn't be the focus and displacement increases isn't necessary when you mess with forced induction.

 

why are there V8s putting down <300, and 2 Liter evos pushing 305?


Boost = artificial relative displacement.

 

I read it wrong and it's all good.

You're actually going to compare N/A vs. F/I?

 

Exactly

Atleast you can admit that. It's alright.

 

it would probably be like having stage 2 stock... and there are alot of things that delayed the 2.4 coming out... so maybe that's why who knows... they might've thought about it initially to have more direct competition for srt 4s or something but because of the issues they changed their mind.. I don't think they screwed up... the 2.4 N/a provides a middle ground price and performance wise to the 2.2 and the ss/sc, and it has some forged internals as well as VVT which are nice bonuses it reacts pretty well to mods, i'd have to say they did a good job.. a 2.4l ss/sc or ss/tc would've been even sweeter but then there would've been only 2 trims really

 

so basiclly without the sc the 2.0 would be worth ****

 

If it was n/a you mean?

I guess the answer is...yes. Small displacement, lower comperssion (atleast than the L61).

But the reason I say "I guess" cause it was designed to have forced induction with it, not to be naturally aspirated.

 

yea basically... i read an article from gm that said that the lsj without the sc put down 145 HP i'm assuming that was WHP since they said the sc gave a 48-50% increase in HP so without the sc the 2.0 would basically be a 2.2. however that's because it was built for the specific application and to have an sc...

 

I would assume lower actually...

L61 - 10.0:1 Compression, 2.2L
LSJ - 9.5:1 Compression, 2.0L

They have actually just about the same valvetrain characteristics. They are also the same cylinder bore. Not being able to ingest as much air as the L61, I would assume lower.

 

not necessarily.....lower comp. doesnt really matter a whole lot.....that just means tht higher comp you run lower boost and make the same power as a low comp. high boost app.....and if it was tuned right it would run right and not be a reliability issue....i just dont believe they wanted to use the 2.4....the 2.0 was probably the cheaper alternative....and maybe they have bigger plans for the 2.4 in the future.....2.0 was probably just the easiest and quickest build to make gm some money without alot of research and development

 

EMISIONS.