evilbada

iTrader: (14)

Boltz and Jordan, Thanks for understanding the point of my question lol.

Eric, so you're saying that if stock 2.0L equipped with 42r ( let's just say stock 2.0L doesn't blow up ) will be outpowered by 2.3L equpped with 42r?

I'm talking about peak hp. Which is mainly why I came up with my question.

Can you open that can of worms? I want to touch, feel, lick the worms until I fully understand even if it involves explanation of VE and such.

I can consult my mechanical engineer friend about those terms later.

Migsubishi

iTrader: (38)

I'm not Eric but I would like to say no, they would make about the same power at the higest rpm the stroker can attain before piston speeds become a factor. Now what makes the difference is that at that rpm where the stroker is done, the 2.0l can spin higher meanwhile utilizing the turbo further and making more power at a higher rpm than the stroker can obtain.

Now if you can make a perfectly square stroker design that can match rpm with the 2.0l w/o running into insane piston speeds causing the pistons to litterally out run the combustion. Then I would say at 10k rpm there would be little to no difference.

Just the stroker would be more fun under the curve but that is ofcourse in a perfect world, in this case its not which is why we have walgreens...lol

Hope that helps

evilbada

iTrader: (14)

Thanks for nailing my question.

What's the science behind this?

If the bore was increased to 2.3L instead of stroke, would that still be the case?

Until this point, my understanding was that bore will give more peak hp but stroker will make same peak hp.

And at upper rpm range where the torque meets for 2.0L and 2.3L, displacement = displacement doesn't really apply anymore does it?

JordanS4

iTrader: (11)

I believe unless you increase bore and stroke and make them square there is no way a 2.3L will be able rev up to 10k+ RPM. There will still be too much stress on the rotating assembly to support those kind of piston speeds.

Migsubishi

iTrader: (38)

Correct, you will have to increase the bore more than is physically possible on these engines w/o running into the water jacket or making the engine a time bomb.

If you can have a custom dart block designed aroung the 4g63 to acheive these results that would be awesome. At this point I feel you will increase the engines overall size causing many other issues that would cause this to no longer be feasable.

evilbada

iTrader: (14)

actually oversquare engines spin higher than perfect square because pistons travel length is shorter.

Formula 1 engines are oversquare engines and rev past 19000rpm.

So is it safe to say stroker of any kind (doesn't matter 4g63, 2jz etc) does not yield anymore peak hp than its oem motor because it becomes very inefficient at high rpm range?

JordanS4

iTrader: (11)

You are right, F1 has a bore:stroke of 2.5:1. They also idle around 7k rpm?

JordanS4

iTrader: (11)

I don't think it's safe to say that. What about in N/A or S/C applications. I am very curious to understand the physics behind this all. Assuming there is no weak spot on a 2.0 and a 2.3 (anything to prohibit maximum VE that the engine could handle at set RPM) will the powerbands still look like they do in the 3065 chart.

I think the turbo has a large part to play in this and the stoker can't make the big HP numbers on a displacement this small because they take so long to spool up.

What about on a 6.0L vs. one 15% larger like 2.0-2.3 (in this case, 6.9L)

Will they still make the same peak hp?

It seems like although at say 7500 revolutions per minute, both engines are pumping air at the same speed, the 2.3 will take more work to spin that fast vs. less resistance on the 2.0. At the end of the day it is a machine and the efficiency lost to overcome the friction of 7500 rpm on a 2.3 negates the small displacement advantage over it's 2.0 counterpart. Therefore they become equal, or close to it. Maybe?

evilbada

iTrader: (14)

^ that's what I'm trying to find out.

We need an engineer who understand VE in here.

Not some monkey donkeys who spit same information over and over. hehe

I'm getting frustrated.

JordanS4

iTrader: (11)

At the end of the day, it doesn't really matter why, it only matters that. Understanding why for me and you is only for our own curiosity. For tuners/builders it's to make more power. But for the average joe, just analyze the results and build accordingly.

That being said, I still really want to know why lol.

JordanS4

iTrader: (11)

Bobby, call Jackson Auto Machine tomorrow and talk with somebody there. Tell them I sent you. They should be able to explain it in regards to not only the 4G63 but other motors as well.

evilbada

iTrader: (14)

^ I should try that if AMS can't help on this.

I thought Martin was an engineer?

Hopefully, he can jump in on this.

94AWDcoupe

iTrader: (125)

You guys need to start a thread on VE . This is basically the area that seems to be misunderstood. With a better understanding of what VE is and how it is affected in a turbo engine you would have a better understanding of the differences of 2.0/2.3 as it applies to the 4g63.

EvolvedMR

iTrader: (14)

one thing most of you missed but JordanS4 began to hit on is the additional losses on a 2.3.

Think about it, with a longer stroke the 2.3 has to move the piston further - additional friction. At the same RPM the 2.3 piston has to move faster to cover the longer distance in one rotation of the crank. At a faster speed the piston in the 2.3 has more momentum (mass x velocity). It requires more force to stop the piston and reverse its direction. This is offset by the additional fuel and air afforded, but begin to add up as you increase RPM. This is not a linear curve.

At the higher RPMs the forces increase, as well as the friction causing a point where the HP of the 2.3 is matched by the 2.0.

AutoMotoSports

iTrader: (42)

Martin is in CA right now. Ivan would be a better person to help you understand all of this in some more simple terms. I have the answers but with stuff like this I suck at getting them on paper.

I will ask Ivan to come in here tonight and I bet he can get you on track

Eric