Just read all 8 pages of the first post. [wipes brain matter from screen]

[drivemusicnow]

I'm willing to deal with it at the stop lights and just down shift when I want . Who makes the most power and what do they run? Is it Shep? Can a 2.4 move more air than a 2.0 if rpms are not a limit, but the physics of the rod/stroke ratio are?

You're making questions up to get the answer you want.

the people who have made the most horspower (1200 plus) are 2.0s... is that what you want to hear? thats mostly due to the fact that 2.0s have been around forever, and thats the stock motor. Thats what people push harder/further.

You need to set a goal and a budget. Once you decide what 1/4 mile times you want, how much you want to spend, and what type of driving characteristics you want, then you'll be able to decide on an engine.

There is a huge difference between having more peak horsepower, and being faster.

I'm going to be building a 2.4L for my road racing car, however right now I'm just building a budget 7bolt that I'll blow up at a later date.

 

[dsm-onster]

No. I am not making up questions to hear the answer I want... I want a stroker to rev as high as a 2.0 w/out issue.

I don't want to build a great motor, then want to go to yet another level and have to scrap it becasue I can't get it to rev high enough to flow what my new goal would be. I'm getting from my research that if you build a stroker then you are limited with your redline. I want to know if a properly built 2.0 can flow more for the same dollar amount it would take to build a 2.4 stroker. I don't want to have to run 50 psi when I could rev to 10,000 rpms Either way, I'll need a built motor and about the same turbo to accomplish either feat. But will it cost more to build a 2.0 that will outflow a 2.4 Perhaps not, if you can rev the 2.4 to 2.0 rpm potentials... Enter the long rod stroker...

Do you see what I'm trying to accomplish here? I don't want to build and have to scrap my work. As I will never stop modifying. Chances are, I will never be satisfied... I've just come to accept it... I like to tackle the feat more than the magnitude of the resulting thrill under my right foot. I'm an engineer at the crux of myself. I'll put a better driver in my car if I had the money to afford that right now. My intentions are well beyond most on DSMTuners. But only because this has more meaning than just the experience of speed, power, and the illusion of control.

If you have a longer curve, you have more chance to get power under it.

 

[drivemusicnow]

If you are going for a drag only setup, It is probably cheaper in the long run to use a 2.0.

If you are going to be driving this on the street, want to put down amazing drag times, I'd suggest the 2.4LR.

If you're going to transition slowly from one to the other, I'd say 2.4LR...

The key is that no one has every really pushed the 2.4 to its limits. There aren't any Drag only 2.4L powered dsms that I know of, as it is a semi-new concept and no-one has put as much effort into it.

If you want to do something cool in the DSM world, run 8s with a 2.4

 

[dsm-onster]

AH! now I'm on the same page as you... There is no real answer to my question because there is not enough real world experience dabbling w/ the limits of the stroker... Thank you very much for the input. I think the LR stroker is my best and ultimate option. When the time comes, I'll feel alot better investing time, money, blood, and sweat in this. Thanx.

 

[Turbocharged]

Do you see what I'm trying to accomplish here?

No, I dont think anyone does but we have asked you what your goals are. All we know is that you want to build a 2.4 that can rev. As has been stated, they have been known to rev in the 9.5k region. I personally dont see the point of the high rev craze.

And no, high revs dont mean high horsepower (Im sure you understand this). Its all about the setup. You wont be disappointed with the 2.4 LR.

 

[dsm-onster]

If you build a 2.4, and you get to a point where you want more flow than it can deliver at 7500 rpms, and it cannot rev beyond that safely, then you've reached a point of impass with respect to the componets you've bought for the setup... If a 2.0 can rev higher and that revving potential offers more potential flow than a .4L more volume, then why build a stroker if drivability is not a concern just traveling 1320 feet as quickly as possible? But my question is already answered... MY goal is to build so as to have room for future growth. Even in the end where this car would be w/ the likes of Tort, Shep, Buscher, etc. Yes, these are fantastic, beyond conventional goals. But at the end of all things, I don't want to build myself into a corner.

 

[nanokpsi]

If you build a 2.4, and you get to a point where you want more flow than it can deliver at 7500 rpms, and it cannot rev beyond that safely, then you've reached a point of impass with respect to the componets you've bought for the setup... If a 2.0 can rev higher and that revving potential offers more potential flow than a .4L more volume, then why build a stroker if drivability is not a concern just traveling 1320 feet as quickly as possible? But my question is already answered... MY goal is to build so as to have room for future growth. Even in the end where this car would be w/ the likes of Tort, Shep, Buscher, etc. Yes, these are fantastic, beyond conventional goals. But at the end of all things, I don't want to build myself into a corner.

Seriously, its easy
A 2.0 @ 10k rpm will have the same piston speeds as a 2.4 @ 8800. Also, a 2.4 @ 8800 has ot capacity to move more air than a 2.0 at 10k.

Why do all the big names runs 2.0????
Also, pretty easy.....
torque, and gearing
The two set ups will make similar power, but the 2.4 will make a good bit more torque. Given the durability of the driveline through the years of DSM growth, we didn't need more torque at the strip which would break more crap.
Gearing is a factor because you obviouly don't want to shift more than needed. On a 700-750whp awd, you might need to throw it into 5th shortly before the traps with an 8800rpm redline, but not on a car that can rev to 10k (this example just to illustrate a point).

 

[dsm-onster]

Seriously, its easy
A 2.0 @ 10k rpm will have the same piston speeds as a 2.4 @ 8800.

This is good to know! Do you have calculations that you've used? Or does this come from personal or others experience? I would not mind the stroker so much, IF the same forces are exerted on the rotating assembly at the same horspower level or higher.

Some of this is bench racing. However, bench racing is somewhat neccesary when establishing a budget and shoot for the long term. A stroker at 8,800 rpms (21,120 liters/min) has the potential to flow 5.3% more air than a 2.0L at 10,000 rpms (20,000 liters/min).

If there are the same forces exerted on the rod bolts, wrist pins, etc.; then it is safe to assume that the costs to build a bottem end capable of handling 10,000 rpms in 2.0L trim would be the same to build a stroker. MINUS the crank and, if your block is in good shape, a bore and time pulling the block. 5.3% more horsepower at 500hp = 27hp more. Longer stroke = more torque at relatively the same hp level. So, though it seams the cost vs. horsepower increase doesn't seam worthwhile, the increases in usable torque are probably worth costs, correct?

Why do all the big names runs 2.0????
Also, pretty easy.....
torque, and gearing
The two set ups will make similar power, but the 2.4 will make a good bit more torque. Given the durability of the driveline through the years of DSM growth, we didn't need more torque at the strip which would break more crap.

This makes sense, but I was under the impression that horsepower is "torque over time". This means that if you have more horsepower you can apply the same amount of "torque over time" as a higher torque setup w/ less horsepower. . . . Also, I'm ASSuming stress on components is a function of "force over time". So it seams to me that a high horsepower, low torque engine can fatigue transmission components as quickly as the converse. Please show me wrong as I'm just infering from my own point of view and a fragmented ME 101 class.

Gearing is a factor because you obviouly don't want to shift more than needed. On a 700-750whp awd, you might need to throw it into 5th shortly before the traps with an 8800rpm redline, but not on a car that can rev to 10k (this example just to illustrate a point).

I agree completely. This is a huge factor for me. To me, alot of time (measured in tenths) is lost in shifting throughout 1,320 feet.

 

[Turbocharged]

This is good to know! Do you have calculations that you've used? Or does this come from personal or others experience?

Its simply (100/88)*RPMs

 

[nanokpsi]

This is good to know! Do you have calculations that you've used? Or does this come from personal or others experience? I would not mind the stroker so much, IF the same forces are exerted on the rotating assembly at the same horspower level or higher.

Some of this is bench racing. However, bench racing is somewhat neccesary when establishing a budget and shoot for the long term. A stroker at 8,800 rpms (21,120 liters/min) has the potential to flow 5.3% more air than a 2.0L at 10,000 rpms (20,000 liters/min).

If there are the same forces exerted on the rod bolts, wrist pins, etc.; then it is safe to assume that the costs to build a bottem end capable of handling 10,000 rpms in 2.0L trim would be the same to build a stroker. MINUS the crank and, if your block is in good shape, a bore and time pulling the block. 5.3% more horsepower at 500hp = 27hp more. Longer stroke = more torque at relatively the same hp level. So, though it seams the cost vs. horsepower increase doesn't seam worthwhile, the increases in usable torque are probably worth costs, correct?


This makes sense, but I was under the impression that horsepower is "torque over time". This means that if you have more horsepower you can apply the same amount of "torque over time" as a higher torque setup w/ less horsepower. . . . Also, I'm ASSuming stress on components is a function of "force over time". So it seams to me that a high horsepower, low torque engine can fatigue transmission components as quickly as the converse. Please show me wrong as I'm just infering from my own point of view and a fragmented ME 101 class.


I agree completely. This is a huge factor for me. To me, alot of time (measured in tenths) is lost in shifting throughout 1,320 feet.

http://davewin.com/tech/mean_piston_speed.shtml

There is the piston speed calculator I used. There are some more advanced one that include rod length, but as I said before, going to a "l rod" 2.4 only buys you 50 more rpm to egual the same piston speeds.

On your torque question, the 2.4 actually makes more torque throughout the rev range, since it won't rev as high, it has to make more torqe to achieve the same power. Take into account that it should be making more power as well, and there is some more addeed torque. If you can make ballpark similar power, but with less torque, your driveline will be happier. It just might not like to shift at 10+k.

 

[Turbocharged]

http://davewin.com/tech/mean_piston_speed.shtml

There is the piston speed calculator I used. There are some more advanced one that include rod length, but as I said before, going to a "l rod" 2.4 only buys you 50 more rpm to egual the same piston speeds.

Rod length has nothing to do with piston speed. Your rods can be 3 meters long and it wont effect the speed of the piston. The speed is ONLY dependant on the stroke and RPMs.

 

[dsm-onster]

Rod length has nothing to do with piston speed. Your rods can be 3 meters long and it wont effect the speed of the piston. The speed is ONLY dependant on the stroke and RPMs.

Correct. No one cares about speed. But acceleration (momentum) is what breaks stuff. Rod/stroke ratio is directly related to piston acceleration. . . So although speed itself is not a factor, acceleration is. Many equate speed w/ acceleration. So I understand what you are saying AND what others have said.

Rod Length Relationships
Engine Formulae, 4-Stroke - Engineers Edge
Piston Speed & Acceleration
Piston displacement, velocity, and acceleration
Connecting Rod vs. Stroke

 

[nanokpsi]

I'm sure my point was conveyed