I got a quick question here. With swapped springs and forged valve train parts, what is the maximum RPM a LN2 is capable of running before ANY part of the valvetrain breaks?
I mainly ask this because I intend to push the motor to it's max rpm (minus a few hundred to stay on the safe side) and increase the max torque to about 5000 rpm and max power to as high as the rpm band and torque at that rpm will let me go. It's times like these when I wish the LN2 or even an ecotec had some kind of VVT or dual preset profiles, kind of like the civics, beemers, and most new performance motors on on the market today...not saying that our cars are designed for high performance, but hey, honda did it to the civics anc accords, so why can't GM do it to the J's? But yea, as of now, all I need to know is the max redline I can bring the engine to with an aftermarket valvetrain.
And how do you plan on reving higher than the rev limiter?
http://www.cardomain.com/ride/2090440
step 1) read every valve train related tidbit on the web
step 2) buy a textbook concerning high-performance automotive valve trains
step 3) come back to this post and laugh at how ridiculous your question is
fortune cookie say: better a delay than a disaster
^ Good post ^
I've heard of one being pushed up to 8500. (granted thats full valve train, new crank, etc. - basically a new engine)
Its all dependent on what you do to it. As for torque peaking at 5k, good luck with that. You can probably get it to hold pretty steady up to there, but I don't see you getting it to peak there.
The LN2 is incapable of VVT because its OHV.
And as for the ecotec: ECOTECS ARE VVT! Look at the cover of a 2.4, its printed right on it.
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Quote:
The LN2 is incapable of VVT because its OHV.
This is not true. VVT is not the exclusive domain of OHV engines. The simplest forms of VVT involve retarding the cam as RPM increases which can be accomplished through timing chain manipulation.
-->Slow
Quote:
The LN2 is incapable of VVT because its OHV.
LS7 has VVT IIRC, and it's definately pushrod powered.
The J-body ECOs are NOT VVT.
Race cars are NEVER VVT
fortune cookie say: better a delay than a disaster
lmao they have vvt because they need it. They rev high only because of where there power band is present.....your powerband is present before 6500...keep it that way. Revving high doesnt always mean your making power. everyone gets carried away with the two lobes on the cams with hondas and what not and say oh well i want to rev high..... lol if you want the two lobes they have and you want to rev high just to make 130 hp that their single cams do make.....simple go buy a honda lol.
And again how do you plan on reving that high?
http://www.cardomain.com/ride/2090440
So can I ask you why you want to max out your RPMs? Have you been on a dyno? Does your power curve continue to rise before you hit your rev limiter? The only reason you should ever go over your rev-limiter is if that is where your power band is. Its useless to rev past it if that is not the case.
Its impossible for anyone to judge the breaking point of a motor, as all motors are different.
This doesn't exactly tie in directly, but my roomie has a 91 2.2L TBI LN2, and oddly enough, it doesn't have a rev limiter that we've been able to hit. That car has seen a tach indicated 6800+ rpms before in 1st gear on an attempt to blow it up, and 6500+ on more occasions that I can count just because we were punishing the car for moving slower than a turd in a river of molasses.
Anyways though, couldn't HPT easily take care of the rev limiter in the situation this thread refers to? Beyond that I'm not touching this one, to have an LN2 make power at where you're talking about is going to cost more money than the car + your current education is worth.
yes hp tuners allows you to be able to change your rev limiter as well as many other things. although unless thats where your power curve is, its useless.
Robert Freeman wrote:I got a quick question here. With swapped springs and forged valve train parts, what is the maximum RPM a LN2 is capable of running before ANY part of the valvetrain breaks?
I mainly ask this because I intend to push the motor to it's max rpm (minus a few hundred to stay on the safe side) and increase the max torque to about 5000 rpm and max power to as high as the rpm band and torque at that rpm will let me go. It's times like these when I wish the LN2 or even an ecotec had some kind of VVT or dual preset profiles, kind of like the civics, beemers, and most new performance motors on on the market today...not saying that our cars are designed for high performance, but hey, honda did it to the civics anc accords, so why can't GM do it to the J's? But yea, as of now, all I need to know is the max redline I can bring the engine to with an aftermarket valvetrain.
you do realize the question you are asking is an "INFINITE" question, right?
its like asking,
-if you lift weights for 2 years and eat right, what will my max bench press or squat be?
-if i build an engine with these parts, what will the max hp be?
understand that until you actually accomplish the feat, and then test it.... in which for your case, to find out the max, you basically need to build, test, then DESTROY the engine, cause you really WILL NOT find out the max until something gives.... you simply will not have an answer.
secondly as most have pointed out, redline is a bit less important than knowing where your power band is. think about it. if you make all your power between 2500 and 6200..... why would you have a need to rev up to 8500 -9000? a place where power would be declined...
if you are really into high rpms, then look into destroking an engine. it will decrease displacement, but you normally gain higher revs......and a larger engine build price.
in all honesty, i would heed ohv notecs advice on doin some research on engines and power bands....
revving higher does not make u faster. especially when it comes to the ln2 as its max hp tops out at 5k rpm and it falls on its face 5,500
Working on obtainting an M-Class license... ?? Hint: 2 wheels.
Yea, guys, I'm aware that reving higher doesn't make you faster, but if a car made a peak of 150 ft-lbs of torque at 4000 rpm and another made a peak of 150 ft-lbs of torque at 6000 rpm and the torque tapered off at the same rate as the rpms rose past their torque peak, then the one with the torque peak at 6000 rpm would have more peak HP than the one with the torque peak at 4000 rpm. I basically want the car to rev as high as it can so I can push for the torque to peak as high as I can and try to get it to flatline or SLOWLY taper off as it rises from the torque peak to redline. This way it would be making more power at the higher rpm since the horsepower peak will be at or just below redline. I know that this mostly involves a cam regrind, since if I just upped the limiter I'd be losing power in rpms higher than the engine is designed to make. That is why I want to make the engine make more torque in top end rpm so it can gain power up to the new redline. And yes, I would be able to move the rev limiter up with HPT, I've got the tutorial on it. I'm not that much of a retard at this kind of stuff, as I know what I want, I know what I'm doing, and I sure as hell know what I'm asking...obviously it's a matter of clarification. And no I don't intend for the engine to rev past 7000 rpm.
So again, what is the fastest anyone has heard of an LN2 reving at with aftermarket valvetrain parts?
Robert Freeman wrote:So again, what is the fastest anyone has heard of an LN2 reving at with aftermarket valvetrain parts?
It can rev as fast as your wallet can spit out bills...
If all you want is 7k, just grind the spring seats down and throw in some Comp beehive 105# LS1 springs.
fortune cookie say: better a delay than a disaster
Like Notec said, if it is only 7k you want to redline at, then that isn't a huge problem. If you wanted to go far past that, then HPT is going to be a good waste of money since you don't have the ability to adjust fuel trims or spark past 7K if I remember correctly. But why do you want a redline of 7k and max torque at 5k anyways? You're going to have like a 500 rpm window between max torque and max horsepower. You would need a 9-speed gearbox just to get any good use out of a motor like that (and frankly, I don't think it is physically possible, because you would most likely still e building power past 7K)
Edit: Also, at higher RPM's you are going to need to worry about more than just the cam profile to make as much power as possible. Manifold designs, throttle body/bodies size, head ports and valve diameter play a large role in where the power band will be.
Edited 1 time(s). Last edited Sunday, November 04, 2007 8:41 AM
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"Youth in Asia"...I don't see anything wrong with that.
Robert Freeman wrote:Yea, guys, I'm aware that reving higher doesn't make you faster, but if a car made a peak of 150 ft-lbs of torque at 4000 rpm and another made a peak of 150 ft-lbs of torque at 6000 rpm and the torque tapered off at the same rate as the rpms rose past their torque peak, then the one with the torque peak at 6000 rpm would have more peak HP than the one with the torque peak at 4000 rpm. I basically want the car to rev as high as it can so I can push for the torque to peak as high as I can and try to get it to flatline or SLOWLY taper off as it rises from the torque peak to redline. This way it would be making more power at the higher rpm since the horsepower peak will be at or just below redline. I know that this mostly involves a cam regrind, since if I just upped the limiter I'd be losing power in rpms higher than the engine is designed to make. That is why I want to make the engine make more torque in top end rpm so it can gain power up to the new redline. And yes, I would be able to move the rev limiter up with HPT, I've got the tutorial on it. I'm not that much of a retard at this kind of stuff, as I know what I want, I know what I'm doing, and I sure as hell know what I'm asking...obviously it's a matter of clarification. And no I don't intend for the engine to rev past 7000 rpm.
So again, what is the fastest anyone has heard of an LN2 reving at with aftermarket valvetrain parts?
well i'm not being rude in saying this so dont take it that way, but you just stated and i'll quote you:
Quote:
I know what I want, I know what I'm doing, and I sure as hell know what I'm asking...obviously it's a matter of clarification
if you know what you are doing and what you are asking, then as OHVNOTEC just posted, and i'll quote him:
Quote:
It can rev as fast as your wallet can spit out bills...
thats your honest answer. you engine will rev as high as you can possibly afford it to rev. spend the cash, lighten up the parts, perhaps get some titanium springs, titanium rods, forged lightened crank. if you dont intend for over 7k, then u have no worries. prob wont need many of those parts.
but honestly, an engine will really only rev as high as the parts inside, and the computer allowed. you know this, as for highest so far? no clue, no one really posts about how high they can rev. its kinda irrelevant in most aspects. for what you want to accomplish though, you should be fine with upgraded valvetrain and forged parts.
Sorry I haven't chimed in on this sooner, but, as usual, I've been busy(been reading, but not enough time to post up).
Robert, you have the '98+ 2200, there are a few things that are working against this motor favoring higher rpms. First and foremost as we know are the cam profile, the head's port design (including the valve sizing) and valve train. As we know we can do a cam regrind, port and polish the head and get bigger valves (atleast the +1mm). The problems that are more difficult to deal with are with the valve springs and the intake manifold.
We have yet to find a reliable solution to the valve spring situation on the 2200s and test it . Yes, we can use the valves out of a pre-'98 2.2L, combined with a small amount of machining to get the LSx springs to fit (1.8" as opposed to 1.6"). Now what we have to deal with is the difference in valve train geometry and valve cover clearance. The longer valve stems will require longer pushrods to equal out the difference in length, which will raise the rocker arm location. Now you won't be able to use the stock rocker arms, because they are not adjustable, so you have to go to aftermarket rocker arms. With the location of the rocker arms raised, will you have enough thread engagement on the studs (from Crane or ARP, 8mm base [since this is a 2002] with 3/8" top)? You'll also have to deal with the rocker arm to valve cover interference issue also. Best thing here is to make a spacer to go between the VC mounting rail and the VC it's-self.
Now the intake manifold is going to be a challenge. The long, narrow runners are designed for low rpm torque and the rectangular ports are unique to the 2200. You can reach the higher rpms with this intake, but you won't get the most out of your motor, i.e. you'll be choking your motor down. Unless you want to spend $1200 on a custom made intake or build your own, you'll have to live with it.
You need to also remember you have the 4speed automatic transmission (4T40E), which comes with a 3.63:1 final drive and a 2375 rpm stall speed torque converter. If you build this motor to turn the rpms you want, the car will be slower, because you'll be out of the gear range of this transmission. As for the TC, you can get an aftermarket one or have one custom made. The Yank 3000 rpm stall TC, like I have, is a good one and can be found on eBay from time to time. As for the final drive (differential), you can get one from a J-body with a 2.4L, as they came with a 3.91:1 final drive. edit: Look into the Team Green Limited Slip Differntial Insert to aid with traction.
Rebuild the tranny with the Bendex Blue Plate Special rebuild kit and tun the shift points with HPT and you'll do much better, but you wouldn't reach quite as high of an rpm as you plan.
A final thing to consider, this motor has a long stroke and short connecting rods (a rod-to-stroke ratio of 1.65:1), which favors low to mid range torque over high rpm HP. This design will respond well to over-sized runners, ports and valves with minimal loss to the low end torque, but it won't gain as much in the upper rpms as a short stroke, long rod motor (such as a Honda) will. A torque peek in the range of 4000-4500rpm, a horsepower peek in the range of 6000-6500rpm with a rev limit of about 400-600 rpm higher than the hp peek and the max shift point about 200-400 rpm about HP peek would be great. The stock bottom end can be made to handle these rpms (N/A) with some custom work, but forged rods and pistons would be the way to go. Besides, that custom work would cost as much as forged parts would, but without the added durability and reliability. You could boost or run nitrous on the forged bottom end, if you decided to.
Edited 1 time(s). Last edited Sunday, November 04, 2007 4:59 PM
Hmmm, thanks MadJack, didn't know that my tranny was limiting me that much. To be honest, in quite a few years from now, if I keep the car and I get another as my DD then I might swap the auto tranny for a manual tranny (assuming they will still be able to be found the for the platform), and get into some welding for the requirements for a manual. But as for now, you do make a very good point that I over looked. As far as all that headword goes, that is a LOT of stuff to do to it just to get a few more revs out of the motor.
So I just kind of figured that since it's an I4, it should be made to produce it's strength at top end vs bottom end since most v6,8,and 10s make their strength in their bottom end giving them a lot more acceleration from zero than our I4s. So natually since an inline 4 can rev higher and won't produce as much bottom end torque as a v8, it should be made to produce it's power in the top end for speed vs acceleration. But so far everything I've heard states that the 2200 is basically made like most v6,8, or 10s as far power band goes, which honestly only makes sense as far as fuel consumption goes, which makes sense in it self since our cars are economy cars.
Also, I figured that since turbos produce more torque the faster the engine goes (to a point), if I set the turbo to boost me at top rpm where the torque would already be somewhat high after mods.
I honestly don't see the point in raising low end torque since in wot the engine is mostly in mid to high rpms, except for the start from the dead stop.
