1st gen vs LS platform

[clutchdust]

I'm just curious what others think, especially if you have practical experience as mine is pretty limited.
So I'm wondering, given a set of limitations, what do you think the max potential from the two platforms are?
Here's the limiting factors, trying to keep it as realistic as possible.

• 
  Limit displacement to 6.0L

• More or less factory configurations, i.e. no over head cam conversions. Such things as splayed main caps or shaft mounted rockers are good since they don't fundamentally change the architecture of the engine

• Normally aspirated, no "power adders", all motor

• Pump gas friendly

 

[turtlevette]

It's all in the heads, so if you can get a set of very high flowing heads for the Gen1, it'll be right there with the LS.

I'll never bother with an LS. It's too hard to shoehorn in.

 

[mrvette]

It's all in the heads, so if you can get a set of very high flowing heads for the Gen1, it'll be right there with the LS.

I'll never bother with an LS. It's too hard to shoehorn in.

I dunno man, something happen to this engine, and I would have to go LS, hundreds of guys are doing it, there is a sticky thread over 'there' with some 2600 posts on the topic, far to much to read at this point.....

:skeptic::amazed::thumbs:

 

[Ozzy]

LS all the way.
6 bolt mains aint enough for you?
Then you might wanna step up to the LSX block, the factory guys rate it good for 2500 hp..

LS7 heads kick ass if those shitty old LS1-2-3-6 heads aint enough for ya.

Stock LS1 is lighter than any stock 5.7 1st gen anything.
Talking all oem built parts here, great performance before you step into the aftermarket of hell.

Show me a 5.7 that makes 350 hp at the crank and will get 30 mpg , no problem you say - as the LS1 is a 5.7 :yahoo:

Must not be a huge problem for an engine swap as th Ls is the most popular swap for Mazda Miata Mustang Jeep ect ect ect .

 

[mrvette]

LS in my wife's MIATA....hummm.....

:yahoo::rofl::rofl::goodnight:

 

[Garys 68]

If your goal is only hp, either would work.
If you factor in reliability, drivability, fuel efficiencey, the LS wins all the way.
The LS heads, electronics, heads, SPFI, etc were all engineered to work together to give great hp AND efficiency. Just look at off the shelf heads, L92 heads are cheap and flow as good as high dollar SBC heads.
The sequential port fuel injection, combined with the heads, compression ratio, electronics, etc gives near 30 mpg and can provide a perfectly streetable 500hp. Just look at the LS3 package in the new camaros/corvettes.

 

[turtlevette]

Ok, Let's boil this down:

A cylinder case is a cylinder case. Steel splayed main caps are about as strong as the 6 bolt. A cylinder case does not make power, it just has to withstand it. Aftermarket SB1 blocks are strong or stronger than the LS.

Aftermarket SB1 heads are not about fuel mileage. They're about power. There is no reason an LS1 design could not be duplicated with appropriate manifold to produce the same result, ie power and fuel economy. Its just that there's no market for it.

 

[mrvette]

Ok, Let's boil this down:

A cylinder case is a cylinder case. Steel splayed main caps are about as strong as the 6 bolt. A cylinder case does not make power, it just has to withstand it. Aftermarket SB1 blocks are strong or stronger than the LS.

Aftermarket SB1 heads are not about fuel mileage. They're about power. There is no reason an LS1 design could not be duplicated with appropriate manifold to produce the same result, ie power and fuel economy. Its just that there's no market for it.

OK, having said THAT, which makes sense to me, and the prime reason I have not upgraded yet....the trick is....how to get the fuel economy outta my '89 truck 4 bolt block, L98 engine and not kill the hp??

modern computer? what?

sounds like it maybe easier to just junkyard source the LS engine and then sell this engine....:gurney:

 

[turtlevette]

[OK, having said THAT, which makes sense to me, and the prime reason I have not upgraded yet....the trick is....how to get the fuel economy outta my '89 truck 4 bolt block, L98 engine and not kill the hp??

modern computer? what?

sounds like it maybe easier to just junkyard source the LS engine and then sell this engine....:gurney:

You got to remember that we will never get the numbers the c5/c6 guys get, due to higher rolling resistance, caliper drag, poor aerodynamics, less efficient drivetrain etc. You ever try pushing one of these friggin things?

 

[mrvette]

[OK, having said THAT, which makes sense to me, and the prime reason I have not upgraded yet....the trick is....how to get the fuel economy outta my '89 truck 4 bolt block, L98 engine and not kill the hp??

modern computer? what?

sounds like it maybe easier to just junkyard source the LS engine and then sell this engine....:gurney:

You got to remember that we will never get the numbers the c5/c6 guys get, due to higher rolling resistance, caliper drag, poor aerodynamics, less efficient drivetrain etc. You ever try pushing one of these friggin things?

I have '89 vette wheels and 255/275-50-17 tires...C4 and O-ring calipers....garage floor has maybe a 2" slope to the door in the wheelbase of the car, fairly typical I would say.....and it coasts back out when released....so I dunno rolling resistance is much more ....aero is something I can't really quite buy into....except maybe windshield rake.....maybe to put 30wt and posi add into the diffy?? 200 4r auto already, wish it was a stick and would have been...back 14 years ago....

I do still think of modern electronics, though...kicking that one around still...

crank trigger, cam sensor, 4 coils, waste spark? 8 coils? dunno that is much of a gain....so to the computer with sequential? instead of batch?....

:shocking::search::beer:

 

[vette427sbc]

This is from pro-touring.com

Most folks don't know the real reason why the LSx engines are so damn good. So I will provide an anecdotal comparison in laymen's terms so that everyone gets it.

The LSx technology is really not anything new. In 1988, you could get what were called Dart "Buick" conversion heads for your small block Chevy. What? Buick, huh? Forget the name. It's irrelevant. What these heads offered were the following:
-Shallow valve angle: 14 degree as opposed to the stock 23 degree
-Raised Intake ports
-Spread, symmetrical intake and exhaust ports (as opposed to the standard siamesed port locations)
-Small fast burn chambers (No. GM did not invent that term. Still pisses me off)

The heads flat out made killer power. They were commissioned by--you guessed it--Buick for NASCAR use. But the bare castings alone cost about $3500. Exclusive race car limited production stuff. And they came semi-finished so that each engine builder could machine and port them to their own specs. More $$$ THEN you had to buy conversion pistons, conversion intake, conversion headers and Jesel rockershaft valvetrain to accomodate the revised valve angle and port locations. All told the typical conversion engines started at $35K. Other conversion applications followed. Probably the most well know is the Dart Big Chief (aka Pontiac) big block conversion heads. All or most of these projects were funded by GM racing and produced by aftermarket
casting manufacturers for use in NASCAR, Pro Stock, etc. The GM Pontiac big block head program was dropped by GM when the money switched from Pontiac to Oldsmobile--hence the "Big Chief" name.

Whew! Are ya still with me? Sooo what GM has done here is take all that tried and true exclusive race engine technology and put into every V8 car and truck falling off an assembly line. Economies of scale. When you buy an LSx, you are getting shallow valve angles, raised and spread symmetrical ports and other stuff aluminum block castings for assembly line prices. So for a true apples to apples comparison, you really need to compare that LSx engine to a minimum $35K gen one small block. Bargain of the century!! Folks argue the Gen1 vs LSx max power all day long. That's silly. It's where and how in the rpm band it happens. Here the LSx kicks ass because of that technology. I'll say it again the answer to your question is:

-Shallow valve angle: 14 degree as opposed to the Gen1's 23 degree
-Raised Intake ports (straighter shot to valve)
-Spread, symmetrical intake and exhaust ports (as opposed to the standard siamesed intake and exhaust port locations)
-Small fast burn chambers (available on aftermarket GEN1heads as well, but the other stuff is where the big investment comes from
-Revised Firing Order

 

[Garys 68]

Sorry, about the only FI you can run on a Gen 1 SBC is a TBI. The SPFI, higher CR, etc of the LS motors allows a lot of low end torque, lower cruising rpm, all that leads to better mpg. Without cam and crank sensors, you cant get sequential port. Batch fire only lasted a couple years, so I doubt it's much better than TBI at lower rpm.
As for heads, the stock L92 heads probably flow better than most aftermarket and cost about 1/4 the price. So 20+% improvement in milage and better hp. What's not to like. There's even a company selling LS heads that fit on a Gen I, for a couple thousand.
And check out the iron block 6.0 truck motors. They're less than half the price of the aluminum block LS motors.
But if you're only doing it for increased mpg, it will take a while to recover the cost. You can probably do a low milage 6.0 LQ9/4 motor for under $2k with efi.
I've done a 68 vette with 6.0 LQ9 and 72 442 with a 5.3 LM7. The 442 is my DD now (softer suspension). It's an easy swap.
There are still those that want to stick to flathead 8s too, carbed SBC's are next. Great for nostalgia though.

 

[clutchdust]

I think a few posts have gone off track a bit, but there is still some good information here.
The point I was getting at, or at least hunting for, is that for real world, every day power (in other words the most powerful compromise motor you can have) I think the Gen1 motors run out of steam at around 400hp, maybe a bit more, given the factors I listed above. However, the LS motors seem to just about start at that 400hp. Seems like you can get a very liveable, very streetable, very civilized LS build making well over 500hp, maybe even 600+hp. Not that you can't make that kind of power out of a Gen1, but it will be a serious compromise motor. Very difficult to live with every day and unlikely to run on pump gas.
I have been following an article series in Vette magazine where they built a gen1 427 to make well over 600hp. Their objective was to build a gen1 to beat an LS7, which they did. At least in power, but I wonder how it will be for mileage or liveability. I'm sure it will be fun, but it is still a compromise motor. Just like the 355 in my '81, it makes about the same power as the LS1 in the c5. But it gets half the gas mileage and idles rough. I don't mind, because the car is a hot rod, that's what I built. But it just highlights how much better the LS motors are, it can make that much power, idle like a econo 4 banger and still get 30mpg on the highway.

 

[Ozzy]

Interesting that the LS haters all want to compare a mega dollar aftermarket SBC or BBC to an out of the box LS and brag they can make the same or more power. DUH!

Throw away that same money on an LS and then see which makes more power. And still get way better fuel economy.

No one posted that Chevy invented the technology in the LS, just they were the ones that utilized it, but Did Dart build the heads AFTER the gm engineers designed them or did Dart design and manufacture them? My money is on gm engineers designed them and the outsourced production to Dart. I could be wrong but that is my gut feeling. Think about the sbc5.7 zr1, gm designed it, mercury marine cast it.

Wow cast iron block with forged splayed main caps is as strong as an LSX block? Where did you find this info? 2500 hp eats up sbc blocks. main webcracking, and cylinder wall instability come to mind.

all cylinder blocks are not the same when it comes to making hp and lasting, the coolant jackets as well as cylinder wall stability both have a fair amount of influence on the end result.

As one mentioned, there are those that still think the flathead "80" is a performance engine. ( my cousin "flat Dave" included)

To each his own on their preference, for me the sbc has been a great engine, but the younger brother the LS has bested it.

The cast iron block lq9 and lm7 are a far better base to start an aftermarket build on, and hands down a better swap motor for any dd than the sbc.

sbc refers to gen 1

 

[JE Caudle]

If the first generation engine was the better engine GM would have dropped the LS program.

 

[big2bird]

If the first generation engine was the better engine GM would have dropped the LS program.

Bingo. The LS engine is clearly a step forward, and thankfully not backwards. They beat the old Gen 1 in every category.

 

[turtlevette]

Interesting that the LS haters all want to compare a mega dollar aftermarket SBC or BBC to an out of the box LS and brag they can make the same or more power. DUH!

Throw away that same money on an LS and then see which makes more power. And still get way better fuel economy.

No one posted that Chevy invented the technology in the LS, just they were the ones that utilized it, but Did Dart build the heads AFTER the gm engineers designed them or did Dart design and manufacture them? My money is on gm engineers designed them and the outsourced production to Dart. I could be wrong but that is my gut feeling. Think about the sbc5.7 zr1, gm designed it, mercury marine cast it.

Wow cast iron block with forged splayed main caps is as strong as an LSX block? Where did you find this info? 2500 hp eats up sbc blocks. main webcracking, and cylinder wall instability come to mind.

all cylinder blocks are not the same when it comes to making hp and lasting, the coolant jackets as well as cylinder wall stability both have a fair amount of influence on the end result.

As one mentioned, there are those that still think the flathead "80" is a performance engine. ( my cousin "flat Dave" included)

To each his own on their preference, for me the sbc has been a great engine, but the younger brother the LS has bested it.

The cast iron block lq9 and lm7 are a far better base to start an aftermarket build on, and hands down a better swap motor for any dd than the sbc.

sbc refers to gen 1

Where did you find the info that steel splayed mains aren't as good as the 6 bolt setup?????

Ok i could spend several thousand on really good heads for SB1 or i could spend thousands on all the custom parts and pieces i need to fit that LS pig in my engine bay. All my time at $80 hr fabricating motor mounts special brackets, farking around with junkyard computer and harness blah blah blah.

Out of the box LS? You mean junkyard LS from some kid who rolled a Camaro? How do i know the thing isn't cracked before i put all the work into the installation. Better to buy a new one from GM. What's that gonna cost. 7 grand? I could build a nice Gen1 for that. And it slips in and everything bolts up in a few hours and i'm back on the street. Friggin thing isn't sitting up on blocks for a year while i fuss around shoehorning the LS in. If it's so easy why is the thread on CF so huge with all the detail. 100 pages of shit.



All the picts i've seen look like the LS is just too wide and long for the C3. It looks stuffed.

 

[mrvette]

All the picts i've seen look like the LS is just too wide and long for the C3. It looks stuffed.

WTF you think a BBC looks like?? THAT is stuffed.....

prrtt:

 

[Garys 68]

Agreed, the LS is the same size as a gen 1. The engine in the pic is actually moved forward 1".
As for fabricating stuff, no need. Pretty much everything is now available. The price of adapter plates has actually gone down from $100 to about $50.
I've done 2 LS conversions. Went with the iron block truck motors. Both came with accessories and a 6 month warrantee. $900 for an 05 LM7 with 40k miles, shipped to me. I did that swap for about $2500. That's about the price of an aftermarket EFI on a small block.

All the picts i've seen look like the LS is just too wide and long for the C3. It looks stuffed.

WTF you think a BBC looks like?? THAT is stuffed.....

prrtt:

 

[turtlevette]

6 year old engine from a wreck. Iron block 5.3 with 305hp. Sure they gurantee they'll replace it but how about all the work to yank it out and try your luck on a second one. Junkyard motors are a risk. Computers and harnesses sitting out in the weather scare me too. I don't know if the boards in the computer are conformal coated or sealed in silicone. I suspect not. Computer, edge connectors or Molex connectors on the fritz can be a bitch to troubleshoot as the problem will be intermittent.

Budget another 2500 to rebuild it. Then you're up to 5 grand for a 5.3L iron block.

I'm certainly not an LS hater. I love the 5.3 in my Surburban. And the bigger ones definitely rock in the newer vettes. I just don't think its worth it for a C3 retrofit.