My dad said they used to call the type of lower end a 'block stuffer.' It's way stronger than a convention lower end with caps. Hey Will, you wrote less than 99 is cast, while greater than 00 is forged, are you saying that 99's are or are not forged? I think valve springs get you 8k, but I'll find out (bet Ben would know). If there was a strong tranny with a steep ratio, I would be all over the LS-1 for a Fiero, because lower rpm's are more driveable, but it seems you would have to shift too often with a lower reving engine. Can someone with an LS-1/LT-1 list the shifting speeds for each gear?

I meant that to read "99 and earlier" vice "2000 an later".

'99's are cast/PM.

quote Originally posted by Will: The Northstar doesn't have main caps. It has a one piece lower crank case held on by 20 bolts. It's up on a stud girdle straight from the factory. <'99 they used powdered metal rods and a cast crank. For >'00 they went to forged crank and rods.

That sounds interesting... Got any pics. Just for the info I believe the LS1 has a stud girdle on the mains as well. for comparison here is a pic of an LS1 main. As you can see four bolts go the conventional way and two are cross bolted. The windage tray/ girdle attaches on studs that stick up from the outer two conventional main bolts. At first I thought it was just a windage tray but it seem too think for that alone. I am surprised GM is using a forged crank. That is much more expensive to produce.

quote Originally posted by LS1swap: That sounds interesting... Got any pics. Just for the info I believe the LS1 has a stud girdle on the mains as well. for comparison here is a pic of an LS1 main. As you can see four bolts go the conventional way and two are cross bolted. The windage tray/ girdle attaches on studs that stick up from the outer two conventional main bolts. At first I thought it was just a windage tray but it seem too think for that alone. I am surprised GM is using a forged crank. That is much more expensive to produce.

This info and picture is great, thanks. I'm glad we can have a discussion and learn things; I was afraid this was going to turn into a flame war.

I'm surprised they use forged cranks too, but it's cool. I didn't know that, I don't really know much about either the northstar of the LS1, but I would like to learn more. I have done a lot of searching for info on the northstar, but haven't come up with much, probably because they come in caddies which aren't really considered performance vehicles. Well, they perform okay I guess, but they are really luxury cars. Anyway, any good technical links would be great.

quote Originally posted by Borgio: This info and picture is great, thanks. I'm glad we can have a discussion and learn things; I was afraid this was going to turn into a flame war. I'm surprised they use forged cranks too, but it's cool. I didn't know that, I don't really know much about either the northstar of the LS1, but I would like to learn more. I have done a lot of searching for info on the northstar, but haven't come up with much, probably because they come in caddies which aren't really considered performance vehicles. Well, they perform okay I guess, but they are really luxury cars. Anyway, any good technical links would be great.

That's why people have asked why GM would put such a high performance engine in grandpas pimpmobile. Don't judge a book by its cover. The N* is the most advanced American manufactured engine that is put in an auto. I didn't write that it is the best, just the most advanced. For someone to contend that anything is the best is semantic. An SUV won't win a road race, a ferarri won't win an off-road race, a Suzuki RGV 250 won't win a drag with most everything, yet it will win road races over just about everything. Every machine has its intended design, some cater to a specific design, to to a more broad design. The specifiaclly designed machines do what they do very well, the broadly engineered machines do more things, but less effectively. I hear people refer to a given machine as the 'best' all the time and think the deliverer of that statement is naive at best.

As for the forged crank issue, Datsun 280z's used forged cranks, so it's not like we're doing anything groundbreaking. I love it too, but I have a 99 . Oh well, I'm not planning on pumping out 500hp, so it shouldn't matter.

As for caddies, they put 500ci engines in 'em in the 70's. Caddies have generally seem to get the performance motors for some reason.

I love the N* concept, but the LS-1 is sweet too. Finally GM hasn't scrapped a good thing.....yet.

quote Originally posted by I'm Back: The N* is the most advanced American manufactured engine that is put in an auto. I didn't write that it is the best, just the most advanced. I hear people refer to a given machine as the 'best' all the time and think the deliverer of that statement is naive at best.

Talk about naive. The advanced technology in the LS1 dwarfs the Northstar. For that matter, even the LT5 was more "advanced", as the Northstar was derived from it (both were designed in conjunction with or by Lotus). 4-valve design isn't high-tech anymore.

The Millennium Motor-Inside The LS1 Engine

Ruthless Pursuit of Power - The LS6

Dave

Of course the LS1's more advanced. The Northstar is a 12 year old design with a 10 year production life that has averaged 4 years between updates.

The LS1 is a 7 year old design with a 5 year production life and as GM's beloved has gotten incremental improvement every year.

Soon the Northstar will have what the LS1 can't: variable cam phasing. Of course it will be a little while after that before I can get my hands on one of those engines.

Oh yeah.. The Northstar did receive a pretty significan update for MY2K. In addition to the aforementioned forged internals it was fitted with CNP ignition, roller cams and changes to the combustion chamber (including 0.2 drop in compression) which allow it to make its full 300 HP on 87 octane. The LS1 won't do that. Of course the N*'s probably using LS1 lifters upside down like the Vortec 4200.

[This message has been edited by Will (edited 11-17-2002).]

quote Originally posted by Will: The LS1 is a 7 year old design with a 5 year production life... ... improvements which allow [the Northstar] to make its full 300 HP on 87 octane. The LS1 won't do that.

The LS1 has been in production since late MY97. It's not even six years old yet.

You're right, it won't, it makes 405hp on 91 octane.

Dave

quote Originally posted by crazyd: Talk about naive. The advanced technology in the LS1 dwarfs the Northstar. For that matter, even the LT5 was more "advanced", as the Northstar was derived from it (both were designed in conjunction with or by Lotus). 4-valve design isn't high-tech anymore. The Millennium Motor-Inside The LS1 Engine Ruthless Pursuit of Power - The LS6 Dave

So are you saying the LS-1 is the 'best' all around engine? The LT-5 was the ZR-1 engine, right? If the N* was derived from it, then how is it more advanced? 4 valve hasn't been high tech for decades and I never said it was. Hemis haven't been high tech for decades either. Is a N/A pushrod motor so high tech? The primary high tech thing with the LS-1 is are the mains and head design. I'm not busting the LS-1, as of course it is sweet, but how high tech can a pushrod motor get?

As Will pointed out, the N* is getting variable timing cams and for the last 2 years has had a forged crank. CHRFAB is getting 1,200 hp from the N* with 4.6L. In stock configuration, the LS-1 has more HP based primarily upon displacement. What are the engine weights, anyone know?

quote Originally posted by crazyd: The LS1 has been in production since late MY97. It's not even six years old yet.

It's been in production for 5 years. Hence I said it has a 5 year production life. The design cycle was initiated at least 2 years before the production start date, making the design 7 years old.

quote Originally posted by Will: It's been in production for 5 years. Hence I said it has a 5 year production life. The design cycle was initiated at least 2 years before the production start date, making the design 7 years old.

Oh, keep going, the design cycle for the LS1 began in the winter of 1991. Paper to production took over 5 years.

Dave

quote Originally posted by I'm Back: So are you saying the LS-1 is the 'best' all around engine?

Trying to bait me into accepting words you try to put in my mouth, Ed?

quote Is a N/A pushrod motor so high tech? The primary high tech thing with the LS-1 is are the mains and head design. I'm not busting the LS-1, as of course it is sweet, but how high tech can a pushrod motor get?

Oh, I guess you didn't read the links I put up for your EDification. High-tech is making 405hp in a production, 346 cu.in. 2-valve engine with >100,000 mile durability and LEV emissions. I'll go over the significant points:

- deep-skirt block design
- enlarged bearing journals
- six-bolt main bearings
- 88mm head-bolt thread depth, 4 bolts per cylinder instead of 5
- 15 degree valve angle instead of 23
- coil-on-plug ignition
- composite intake manifold
- electronic throttle control
- sintered, forged PM steel, fracture-split, net-shape connecting rods with no balance pads
- 30% reduction in ring tension
- 120 gram weight reduction per piston/rod assembly
- identical intake/exhaust ports
- straight intake port-to-valve path and symmetrical port-to-port/bank-to-bank configuration
- direct injector targeting
- negative deck-height
- rifle-drilled camshaft
- 1.7:1 investment cast steel roller rocker arms
- structural, cast-aluminum oil pan

quote As Will pointed out, the N* is getting variable timing cams and for the last 2 years has had a forged crank. CHRFAB is getting 1,200 hp from the N* with 4.6L. In stock configuration, the LS-1 has more HP based primarily upon displacement.

CHRFAB may have done that on an engine dyno, or maybe even in a racecar, but have they put it in any production vehicle yet? A street-legal Lingenfelter LS1 C5 is running 9's (9.60 if memory serves).

quote What are the engine weights, anyone know?

66lbs lighter than an LT1 by the book, not sure what the exact number is.

Dave

[This message has been edited by crazyd (edited 11-19-2002).]

To me production dates are pure semantics. We're not talking about a decade of difference, and let's face it, every recip engine borrows something from its predecessor, even if that engine was manufactured by a different company. The N* and LS-1 are really differnt engines from the valve arrangement to the dispalcement, to the bore/stroke ratio. I like the N* and think it is such a unique engine. When I started working on it I was almost amused by the water pump design and location, now I realize it's part of what makes it ideal for the Fiero. Every machine has its attributes that work better in certain situations than others, and I think the N* is a better marriage for the Fiero than the LS-1, and I'm never wrong :].

quote Originally posted by I'm Back: Wowwy! Is 9k rpm with the upgraded springs? That's shweeeet, 135 in 3rd. You would never leave 3rd gear in the 1/4, which means fewer shifts, which means less time lost between shifts.

There's more to life than the 1/4 mile. Or at least there should be if you have a 9k capable N*.

If you have to shift at 9k to put the most power to the ground then you've effectively turned your 5-spd into a 3-spd. You'd be better off with a lower (numerically higher) final drive so you could spread that 135mph across five gears instead of three. This would equal quicker acceleration.

In this case it seems that the stock Fiero ratios are better for a 6000 rpm redline motor like the LS-1 because its power band is closer in shape and rpm range to the stock Fiero motors (at least the V6).

But what the LS-1 vs. N8 debate really boils down to is personal taste, just like the 3800 vs 3.4 DOHC debate. Are you a pushrod 2-valve guy or an OHC 4-valve guy?

Great thread so far, guys. I've learned a lot.

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Doug Chase
'88 Fiero Formula 5-spd (autocrosser)
'88 Fiero GT 5-spd (daily driver)
'85 Fiero GT 5-spd (rally car)

quote Originally posted by Doug Chase: If you have to shift at 9k to put the most power to the ground then you've effectively turned your 5-spd into a 3-spd. You'd be better off with a lower (numerically higher) final drive so you could spread that 135mph across five gears instead of three. This would equal quicker acceleration. In this case it seems that the stock Fiero ratios are better for a 6000 rpm redline motor like the LS-1 because its power band is closer in shape and rpm range to the stock Fiero motors (at least the V6).

I would have to disagree with the fact that a 6000rpm redline is better because it's closer to stock. It depends on how much power you are putting out, not just the shape of the power curve. An LS1 doesn't need as much mechanical advantage as the 2.8L does. Look at the different gearing ratios that different cars have. You'll find that typically, the more power you have the higher the transmissions are geared. For example, the four speed that came in the 4 bangers had a final drive of 4.10 and when the V6s got it they changed it to 3.65, I believe. You can spin the wheels in a 2.8 and with the LS1 you get more than twice that force to the ground. You would get to the end of first so quick, it almost might as well not even be there. It might be debatable and it depends on how much traction you get and such, but I think you are looking at this wrong and thought I should point it out.

quote Originally posted by Borgio: Look at the different gearing ratios that different cars have. You'll find that typically, the more power you have the higher the transmissions are geared. For example, the four speed that came in the 4 bangers had a final drive of 4.10 and when the V6s got it they changed it to 3.65, I believe.

That's true, but it wasn't just for performance reasons, it was also for fuel ecomony and cruise RPM. The 4 cyl needs a low final drive ratio so it will get out of it's own way. The V6 has enough power that it can still be reasonably quick with a higher ratio and get better fuel economy, too. The V6 is faster with the 4.10 final drive than the 3.65.

Look at this chart. This compares the overall ratio (gear ratio times final drive ratio) of the Getrag, the Isuzu, and Tremec T-56 with a 3.42 final drive in the Z06 Corvette. I left off 6th gear of the Vette.

code:

---

Getrag  12.64   7.40   4.98   3.39  2.60
Isuzu   12.50   6.83   4.86   3.45  2.48
Vette   10.16   7.08   4.89   3.42  2.87

---

Note that except for first gear which is taller in the Vette, the other ratios are right about the same as the Fiero ratios.

The point I was trying to make was that "It'll be faster because I won't have to shift as much" is a fallacy. If you're trying to accelerate from zero to 135 you can do it faster with five gears than three.

If you have to rev to 9k to wring the most power out of your motor then you'll be faster with a lower final drive.

And as an aside, just because you put stiff enough valve springs in the N* to keep the lifters on the cam at 9k doesn't mean that it's to your advantage to rev it that high. I would be very surprised if GM ground a cam for 9k and then rev limited the motor to ~6500. I suspect to make any useful power at 9k you'll also need new cams.

------------------
Doug Chase
'88 Fiero Formula 5-spd (autocrosser)
'88 Fiero GT 5-spd (daily driver)
'85 Fiero GT 5-spd (rally car)

quote Originally posted by Doug Chase: That's true, but it wasn't just for performance reasons, it was also for fuel ecomony and cruise RPM. The 4 cyl needs a low final drive ratio so it will get out of it's own way. The V6 has enough power that it can still be reasonably quick with a higher ratio and get better fuel economy, too. The V6 is faster with the 4.10 final drive than the 3.65. Look at this chart. This compares the overall ratio (gear ratio times final drive ratio) of the Getrag, the Isuzu, and Tremec T-56 with a 3.42 final drive in the Z06 Corvette. I left off 6th gear of the Vette. code: Getrag 12.64 7.40 4.98 3.39 2.60 Isuzu 12.50 6.83 4.86 3.45 2.48 Vette 10.16 7.08 4.89 3.42 2.87 Note that except for first gear which is taller in the Vette, the other ratios are right about the same as the Fiero ratios. The point I was trying to make was that "It'll be faster because I won't have to shift as much" is a fallacy. If you're trying to accelerate from zero to 135 you can do it faster with five gears than three. If you have to rev to 9k to wring the most power out of your motor then you'll be faster with a lower final drive. And as an aside, just because you put stiff enough valve springs in the N* to keep the lifters on the cam at 9k doesn't mean that it's to your advantage to rev it that high. I would be very surprised if GM ground a cam for 9k and then rev limited the motor to ~6500. I suspect to make any useful power at 9k you'll also need new cams.

I'm actually a little surprised that the 4:10 is faster, I would expect it to feel faster though.

Yes, you would need cams to get any use out of revving it to 9k. www.chrfab.com has the aftermarket cams you would need.

I think it's a little more complicated than saying more gears equals a faster time. It depends on how much power you have, what your power curve looks like(how flat it is), and how long it takes you to shift.

First gear really matters the most, after that only the spacing really matters. But you would actually want the gearing for an LS1 fiero to be even higher than the vette ratios, because it would be lighter.

"If you have to rev to 9k to wring the most power out of your motor then you'll be faster with a lower final drive."

Exactly, the fieros ratios are low for having 300+hp in such a light car, so having a motor that revs high is good. It would be similar to having a higher geared transmission and a engine that didn't rev as high but made the same amount of power.

BTW, where's Ben?! I haven't read a post from him in a while. He needs to get on his freaking computer and post, that is unless he is actually finishing his car. He probably is done, and out driving it right now, or else he would be here.

Only someone who's actually driven a V8 Fiero knows how fast the Getrag's 1st gear wraps out.

I don't have top dollar tires on my car right now, but unless I'm on grippy pavement with warm tires, I have traction trouble through 1st. I don't think it needs any more torque. What it needs is the ability to wrap first out higher. You don't need to wrap first gear out sooner like you would with an LS1's higher torque. In fact, the really high torque small blocks do better with a 2nd gear standing start.

Anyway, with about a 9,500 RPM redline the Northstar will clear 60 in 1st gear with a little taller than stock tire. So a Northstar Fiero is shifting into 2nd about when an LS1 Fiero is shifting into 3rd.

Bringin up an old subject, but I am starting my swap soon, but I am undecided on what trans to use, I might have the option for the five speed or come across a 4T80. The northstar has rifle drilled camshafts. Would you like some pictures of the motor apart from a N* tech manual that is exclusive from GM?

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86 FIERO GT, puttin a N* and tons of other goodies. STAY TUNED

If you have anything that's not in the service manual, that would be great.

What you want to see? Its got everything, heres a taste; yall were talking about the encased crank.

It lists engine specifications too like the stock camshafts have .339" lift for both exhaust and intake, and at .100mm duration intake and exhaust is 244*

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86 FIERO GT, puttin a N* and tons of other goodies. STAY TUNED

here is alink to more than you ever wanted to know about the LS1 http://www.ls1info.com/article.php?sid=202

quote Originally posted by 86 FIERO GT: What you want to see? Its got everything, heres a taste; yall were talking about the encased crank. It lists engine specifications too like the stock camshafts have .339" lift for both exhaust and intake, and at .100mm duration intake and exhaust is 244*

I've seen this book before. It's the "Engine Mechanical" section of the Service Manual split off into its own volume.

That's a reasonably good exploded diagram of the bottom end, though.

[This message has been edited by Will (edited 11-26-2002).]

Have some updates. I will be getting a totalled 88gt that has a 5 speed and I will be stripping it and taking the cradle and all the parts needed for the 5 speed swap. I will be able to use its cradle to get everything finallized without the car being apart.

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86 FIERO GT, puttin a N* and tons of other goodies. STAY TUNED

Dave,

Just a clarification if you can answer some questions.

Which do you consider to be more hi-tech, an LS-1 or a F1 team engine?

Which engines more closely compare to the F1 engines, the N*/Aurora/3.4 DOHC or the LS-1 in engineering, design, and construction?

I'm not knocking an LS-1 at all. I've been racing and building small block Chevy's since 1970 and the LS-1 is, IMHO, the finest evolution of the breed so far.

But from an engineering and technical standpoint, I don't think it holds a candle to the 4.6 DOHC Caddy. That alone doesn't make it the "best" engine for anything as far as I'm concerned, but I still think it's much more technically advanced than the LS-1.

The LS-1 has 71hp/L, the N* 65hp/L (and that's based on the 300hp version). The N*, by nature of the cars it went into, is much more detuned than the LS-1. Where the LS-1 requires a lot of work to up it's power further (because the factory has already done the bulk of the race stuff) the N* is just getting warmed up. Cleaning the heads up and cam's is good for better than 75hp. The LS-1 heads are already, for all intents and purposes, race prepped.

When the N* was released it came with 16 new hi-technology patents (according to GM website). How many for the LS-1? The smaller version of it has dominated the IRL and Indy 500. How about the LS-1?

Asking if CHRFab has put their engines in a "production" vehicle really isn't a valid question because that's not what they build. They build primarily sand rails and the guys I've talked to are very impressed with their N*'s. The have a lot of them out there.

WRT weight, I have in my notes 400# bare, 413# minimum ready to run, and 470# with all factory accesories.

Just because an engine is extremely High-Tech doesn't necessarily mean it's the best engine for any given job. And the definition of High-Tech or Most Technically Advanced is pretty vague in itself. But all of this is like an argument of which sex position is the best. None of them are all that bad.

John Stricker

quote Originally posted by jstricker: The smaller version of it has dominated the IRL and Indy 500. How about the LS-1?

The LS1's done pretty well in the C5R. Maybe a better comparison would be the C5R engine to the Cadillac LMP engine. Both are very close to production engines, much closer than the IRL engine is to the production Aurora engine.

Will,

You're probably right as far as power goes, but that wasn't really my point. Most engineers/enthusiasts feel the most technologically advanced engines in racing are the F1 engines, with the IRL/CART engines not far behind. These require high specific power ouput per litre and that means high rpm. It's very hard to make reliable high rpm with a pushrod motor so OHC designs are the rule, and have been since the days of the Offy.

Don't get me wrong, I like the little Chevy and am always awed at it's success on the track, but to me it's just not as advanced unless you're looking at something like the ZR-1 (which, BTW, I wish I had the money for this http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=1874297086).

John Stricker

quote Originally posted by Will: The LS1's done pretty well in the C5R. Maybe a better comparison would be the C5R engine to the Cadillac LMP engine. Both are very close to production engines, much closer than the IRL engine is to the production Aurora engine.

Does anyone have any pictures of the northstar and 5 speed goin together, what to grind and how it fits on the cradle. How did you set up your mounts. I am interested in seeing everyone setup beings I will be starting on mine soon. Does anyone have any info on how much porting is needed to wake up a northstar?

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86 FIERO GT, puttin a N* and tons of other goodies. STAY TUNED