[RocktimusPryme]

Doesn’t one of the forum moderators have an LS Pontiac?

Again I just feel like the elitist tribalism doesn’t help the hobby. Even if they are using a different engine they are probably still buying replacement dash bezels from Ames etc. It gets bought up all the time, how to keep the youth involved and keep the hobby going. Being inclusive definitely helps. We all have personal tastes. I’ve said before that I think the in between years of 2nd gens are ugly. I wouldn’t exclude them from a Firebird group.

[Stuart]

I prefer it people when stay with traditional Pontiac power in their cars, but understand the reasoning of people who choose an LS or other engine. All in all, it's nothing to get all worked up about - it's their car, it's their choice what to do with it. If you're that offended, buy their car from them and put a Pontiac engine back in it.

People may not have noticed this forum has a section devoted to non-Pontiac motors in Pontiacs.

[Interceptor]

Everyone note the title of this thread. I don't recall the OP asking for any opinions on whether you SHOULD. So quit bickering about that, it's been done to death here ... again.

The simple answer is Yes...with big money and a few caveats. I would say (without having been all the way there myself) that with sequential EFI, computer controlled timing, and a roller cam, it should be possible with good heads. Those of us on this forum better versed than I could chime in on whether this can be done with properly prepped OEM heads, or whether $3000 modern aluminum heads would be needed.

Assuming it WAS feasible, would it get 25mpg with an overdrive trans? Pass reasonable emissions? Last 100,000 miles? Not leak? Not overheat?

Interesting conversation. For my purposes, I just miss turbo power, period, and an LS swap seemed to be the most economical and proven way get it. I wasn't willing to roll the dice on a turbo Pontiac 400.

Sent from my SM-G930W8 using Tapatalk

[autobahn]

Why not complain about a OLDS engine in a Pontiac ,will you turn and walk away when you see THAT????

[i82much]

Originally Posted by autobahn

Why not complain about a OLDS engine in a Pontiac ,will you turn and walk away when you see THAT????

Next people will be putting Pontiac engines in GMC trucks. How disgusting would that be

[JSPONT]

I like my Pontiac, but to be real it is very old technology. The LS platform is well though out with 6 bolt mains, shielded crank, stock heads that out flow any of our old heads and alot of aluminum heads with no port work even. The 4.8 and 5.3 are awesome for boost. My friend has been running in the 7's with his stock bottom end 5.3, with just cam and valve springs for 3 years. He drives it everywhere and get decent gas mileage. It is hard to argue with that. A 7 second Pontiac is a radical race car usually. I think everything has its place. Not saying to cut up a rare GTO or Trans am and stuff an LS in it, but not a big dollar street car, go for it. I love them all. 1200 h.p. on a stock 5.3 with a cam is pretty cool no matter how you slice it.

[Half-Inch Stud]

LS is old tech combined with mis-applied tech to me. Only saving grace is the intake manifold; that which such a runner jobby could be made for the Pontiac.

Modular engine being OHC, FI, dizzyless, OD trans, strong RWD with disc brakes says oh-yea to me.

Any OHC LSs?

[Half-Inch Stud]

Wouldnt it just suck if you go LS hunting and bring home the 2bbl 350 equivalent, and some fella brings the 455 HO equivalent all because ya though modern LS engines were all just enough the same.

So what vehicle should I be pulling the LS motor, Wiring and OD stick tranny from?

[MarkS57]

Originally Posted by Half-Inch Stud

LS is old tech

Good point, it is basically an OHV V8 with all the latest (and reliable- this point cannot be over emphasized) engine management electronics available combined with modern air flow dynamics technology. We are almost back to the OP question. I've thought long and hard about this one. Myself, I am going all GM / AC Delco in my latest update to a Delco SI alternator & HEI combination in my 65 with an MH engine harness. Supplying can't fail (engine) electronics to an auto manufacture like GM seems like is nothing short of military aerospace stuff quality wise...and they want it for nothing!

I would believe a "Try that with a Stoker Pontiac" with an OD 5 or 6 speed and a Q-jet would be way less of a hassle getting fixed (if it ever came to that ) than pulling into what- a GM dealer with a blown LS for service? Really?

Sorry, I will still walk by an LS in any vintage Pontiac, its just who I am and make no apologies. In the end, its their car enjoy!

[Scott65]

Originally Posted by Interceptor

Everyone note the title of this thread. I don't recall the OP asking for any opinions on whether you SHOULD. So quit bickering about that, it's been done to death here ... again.

The simple answer is Yes...with big money and a few caveats. I would say (without having been all the way there myself) that with sequential EFI, computer controlled timing, and a roller cam, it should be possible with good heads. Those of us on this forum better versed than I could chime in on whether this can be done with properly prepped OEM heads, or whether $3000 modern aluminum heads would be needed.

Assuming it WAS feasible, would it get 25mpg with an overdrive trans? Pass reasonable emissions? Last 100,000 miles? Not leak? Not overheat?

Interesting conversation. For my purposes, I just miss turbo power, period, and an LS swap seemed to be the most economical and proven way get it. I wasn't willing to roll the dice on a turbo Pontiac 400.

Sent from my SM-G930W8 using Tapatalk

It could be done. There are numerous members on here who have "modernized" powerful Pontiacs with computer controlled fuel and spark, and OD transmissions and more. Just gotta know the stock Pontiac block has a realistic chance of splitting several hundred horsepower earlier than the corporate block with it's better more modern engineering. It's all apples to oranges really. And I don't fault anybody for wanting better engineered stronger stuff. I personally wouldn't sacrifice a real GTO, Firebird, etc.(OR a real 442, Z28, Chevelle LS6 Big block either) for a modern transplant. But if/when I break my Pontiac block, I'll look seriously at the LS family for my already non numbers matching Tempest.

[Sirrotica]

First thing is the original posters question, " Can old Pontiacs perform like LS motors?"

Now the idea is that you can go to a junkyard and pluck out most any LS engine from a truck and it'll make 600 HP with a few add ons. That isn't the truth, and GM has to bolt a blower on corvette engines to get in the 650 plus HP area. This year they have to top the hellcat so they're up to 755 HP with a large displacement blower.

I own a 400 HP 400 lb ft LS2 in my 05 GTO, I really don't need 200 more HP for a street car. I also own a mildly built 455 Stratostreak that is probably an honest 400 plus HP, either of these is pretty sufficient for a street car, and reliable as an anvil.

6-800 HP street cars, with street tires are just an accident waiting to happen. There aren't many people that can wheel that kind of HP on street tires time after time and not lose control of it. Either engine is plenty sufficient for street duty as it came from the factory. At some point common sense needs to be considered.

Turn off all the driver assist electronics on a 755 HP corvette and it'll be in a ditch or a guardrail in short order. I don't believe that many muscle cars from 50 plus years have any of the driver assist devices installed.

The 410 CI SBC/SBF/LS, derivative that resides in sprint cars is roughly 900 HP on methanol N/A dedicated race engine. They are good for 10-12 nights of racing (250-300 miles) before refresh, I don't care what platform you start with, at that HP level it doesn't last very long if you're using it full tilt most of the time.

Just a reality check for the street section...…….

[HWYSTR455]

Originally Posted by Sirrotica

Now the idea is that you can go to a junkyard and pluck out most any LS engine from a truck and it'll make 600 HP with a few add ons. That isn't the truth, and GM has to bolt a blower on corvette engines to get in the 650 plus HP area. This year they have to top the hellcat so they're up to 755 HP with a large displacement blower.

…..

6-800 HP street cars, with street tires are just an accident waiting to happen. There aren't many people that can wheel that kind of HP on street tires time after time and not lose control of it. Either engine is plenty sufficient for street duty as it came from the factory. At some point common sense needs to be considered.

Turn off all the driver assist electronics on a 755 HP corvette and it'll be in a ditch or a guardrail in short order. I don't believe that many muscle cars from 50 plus years have any of the driver assist devices installed.


Just a reality check for the street section...…….

That's kind of what I've been saying all along, was hoping some would pick up on it. Like I mentioned, they muck with the numbers, the go back and forth between flywheel and rear wheel HP.

Then you look at the engines that are rated higher, and those are different platforms, not your typical 'truck' base. They have beefier parts, and that's why they cost more. That's why I'm saying if you want to 'do it right', it's not going to be with a junkyard truck engine.

Sure, you can bolt it on and 'over-power' the platform, but it's not going to last. That's what I was saying when the guys I know that buy even the 'performance' end of the spectrum are doing add ons and blowing them up. I listen to them, they know you have to go through it to make it live.

Not sure about the whole street HP over 600 on street tires. Yeah, ok, if you have 14" rally IIs with repop redlines on there and all stock suspension, sure, you will be fighting it, but if you go through it and have a decent suspension and tires, you can do 600+ no problem. Ask me how I know.

New 'vette in a ditch with controls turned off? Shoot, half the butt-wipes I see that can afford them will put a Honda Accord in a ditch under power. I have friends that have had vintage iron with 6-71s & 8-71s on built big blocks, on old suspensions and tires, and they had no problem keeping them out of the ditches. It's all relevant.

If you're talking drag racing, sure, dead stop, street tires, anything over 450hp and you will struggle. Especially if it's setup for straight line. You go loose on the suspension, sloppy shocks, weight transfer, skinny-fats, first turn at 80pmh and you will be in a ditch. It ain't like that with a properly setup 'street' suspension on a performance car. It's all relevant.

I can't wait until I get a Go-Pro and get some action shots recorded. You will see what I'm talking about. No, my 1/4 miles times are nothing to be impressed with, but on the street, from a slight roll, yeah. And the open-road 15min power-blasts at triple digits will curl you hair just watching. Not bragging.

Point is, it can be done, there is not that big of a gap between old and new, especially if you apply new tech to older platforms. Driver skill can overcome much of the gaps. Go to a track on an open track night, watch the new stuff and the old stuff run, compare. And there's a lot of crap out there on both sides, so be fair on comparisons.

.

[scott70]

Originally Posted by ta man

Well said..if this forum turns into a bunch of LS nuthuggers and builds I'm gone.
I can appreciate the discussion..but anyone even thinking about a LS swap into their classic Pontiac should find a different forum.

Exactly.

[Schurkey]

Originally Posted by Sirrotica

First thing is the original posters question, " Can old Pontiacs perform like LS motors?"

I don't own anything with an LS.

I was peeved at Jay Leno, when he disgraced his Toronado that GM built a big-block Olds and FWD; when he turned it into LS-powered RWD.

I don't spend much time looking at LS-powered anything at a car show. If it's new enough to have an LS from the factory, it's too expensive for me. If it's an LS transplant, I just don't care.

Having said all that, the LS is the best pushrod V-8 on the planet. It wipes the floor with most OHC V-8s as well. Six years of development head-start, plus The Magic of Overhead Cams, and the 2-valve Ford Modular got it's ass handed to it when GM put an LS in the first model-year vehicle. (MY 1991 vs. MY 1997)

Can old Pontiacs perform like an LS? No.

Hot-roddy folks tend to not really care about emissions control, or long-term (high-mileage) durability, and actually dislike smooth idle and a civilized exhaust noise; lots of stuff in the real world gets compromised to achieve big power numbers. Three letters and the Pontiac is out-of-the-running: NVH. GM doesn't have the luxury of ignoring all the inconvenient details and Government regulations.

Given equal electronic management the Pontiac can come close, cubic inch for cubic inch--but only when using heaps of aftermarket parts. The Pontiac might have a lower-rpm torque peak, and a lower-rpm horsepower peak. That might make it more usable with a conventional, non-overdrive transmission and "highway gears". Add in a 4-plus gear automatic or a 5--6 gear manual, and I'm not sure the benefit still exists.

GM did it the hard way--solid, magnificent engineering of the basic package coupled to electronic controls of a sort not even imagined during the 60s let alone the '50s (and still impractical when the last Pontiac engine rolled off the assembly line.) It's so far ahead of the "old Pontiac" that the only hope for the Pontiac is to utilize as much LS engineering as possible. This would start with the electronic controls. We'd need integrated accessories so the alternator and PS aren't flopping around on spindly stamped-steel brackets. We'd need a proper intake manifold suitable for fuel injection--assuming we aren't going "direct injection". And I don't know what we're going to do about engine weight.

Making a Pontiac perform "Like an LS" is like making ME perform like some top athlete. Yup, I can do it...if I have a big enough head start and I can ignore all the rules. Without a system of handicaps giving me unfair advantage, I don't stand a chance.

[Formulabruce]

Still find it AMAZING that folks talk about high horsepower like they USE it 100% of the time driving.
A 2bbl 1970 Pontiac 400 has MORE Torque at 2400 rpm ( in NORMAL driving range) , than a 6.0 LS LQ4 does from say 2005 .
A Pontiac with a HEI, and Cliff Built Q jet, an OD trans CAN compete in reliability, and fuel economy with an LS engine, IF built to do so.
BUt everyone talks about the "PEAKS" of HP, where we do NOT drive.
I will assume this question should be asked in 2 parts
1. Can a Pontiac built for DRAG racing compete with a LS built for same?, Dunno.
2. Can a Pontiac be built to be reliable and economical for a sporty driver to compete with an LS, OF course it can.
What do you think the PONTIAC Engine plant Engineers worked on when the 265 and 301 were all done?? YUP, Pontiac Built prototype performance Small block Chevy heads ... Yes Pontiac..

[pastry_chef]

Originally Posted by Formulabruce

A 2bbl 1970 Pontiac 400 has MORE

More displacement than a 6.0 L (366) engine, and this is about the simplest method of increasing low end power. Duh.

HP exists off idle and at all RPM, the curve is what is important. LS dyno attached, the already strong power curve really liked the cam swap. I'll assure the passing power is insane.

https://www.hotrod.com/articles/new-...-low-end-loss/

[Dragncar]

Originally Posted by Schurkey

I don't own anything with an LS.

I was peeved at Jay Leno, when he disgraced his Toronado that GM built a big-block Olds and FWD; when he turned it into LS-powered RWD.

I don't spend much time looking at LS-powered anything at a car show. If it's new enough to have an LS from the factory, it's too expensive for me. If it's an LS transplant, I just don't care.

Having said all that, the LS is the best pushrod V-8 on the planet. It wipes the floor with most OHC V-8s as well. Six years of development head-start, plus The Magic of Overhead Cams, and the 2-valve Ford Modular got it's ass handed to it when GM put an LS in the first model-year vehicle. (MY 1991 vs. MY 1997)

Can old Pontiacs perform like an LS? No.

Hot-roddy folks tend to not really care about emissions control, or long-term (high-mileage) durability, and actually dislike smooth idle and a civilized exhaust noise; lots of stuff in the real world gets compromised to achieve big power numbers. Three letters and the Pontiac is out-of-the-running: NVH. GM doesn't have the luxury of ignoring all the inconvenient details and Government regulations.

Given equal electronic management the Pontiac can come close, cubic inch for cubic inch--but only when using heaps of aftermarket parts. The Pontiac might have a lower-rpm torque peak, and a lower-rpm horsepower peak. That might make it more usable with a conventional, non-overdrive transmission and "highway gears". Add in a 4-plus gear automatic or a 5--6 gear manual, and I'm not sure the benefit still exists.

GM did it the hard way--solid, magnificent engineering of the basic package coupled to electronic controls of a sort not even imagined during the 60s let alone the '50s (and still impractical when the last Pontiac engine rolled off the assembly line.) It's so far ahead of the "old Pontiac" that the only hope for the Pontiac is to utilize as much LS engineering as possible. This would start with the electronic controls. We'd need integrated accessories so the alternator and PS aren't flopping around on spindly stamped-steel brackets. We'd need a proper intake manifold suitable for fuel injection--assuming we aren't going "direct injection". And I don't know what we're going to do about engine weight.

Making a Pontiac perform "Like an LS" is like making ME perform like some top athlete. Yup, I can do it...if I have a big enough head start and I can ignore all the rules. Without a system of handicaps giving me unfair advantage, I don't stand a chance.

New V8s, the twin overhead cam, 4 valve hemi in my Tundra would eat a "like" LS alive. They had to make special "pushrod 2 valve" Nasscar engines to compete. Downgrade the engine.My 5700lb 4 wheel drive truck has ran a 14.56 stock, as is just let the rear tires down to 20 lbs. put it in drive and hit the gas. If there was no electronics between the gas pedal and the throttle the truck would shred the tires at the slightest tap of the foot.
That engine is out of the LS league. The whole truck is overbuilt. 2 Tundra 6 speed auto tranys have made it to one MILLION miles and Toyota bought the trucks back.
GMs transmission's are garbage in comparison. On the road, very few vehicles, cars or trucks have more passing power. I work nights with a long straight drive home, more than one new Camaro has slowed down to a 20mph roll and hit the gas next to me. By the time I am in 4th gear they are gone and do not want anymore.

[pastry_chef]

Technology rocks.
http://www.freevalve.com/

[Formulabruce]

Originally Posted by pastry_chef

More displacement than a 6.0 L (366) engine, and this is about the simplest method of increasing low end power. Duh.

HP exists off idle and at all RPM, the curve is what is important. LS dyno attached, the already strong power curve really liked the cam swap. I'll assure the passing power is insane.

https://www.hotrod.com/articles/new-...-low-end-loss/

Funny how all those braging rights are way above the normal driving range, and or economy range.
The original posters question >>"I am amazed by the power, fuel economy and driveability of LS motors. Why can't we do this to a legacy Pontiac 400 motor"
Anyone else on economy at 5 grand rpms?

[P@blo]

Originally Posted by Dragncar

New V8s, the twin overhead cam, 4 valve hemi in my Tundra would eat a "like" LS alive. They had to make special "pushrod 2 valve" Nasscar engines to compete. Downgrade the engine.My 5700lb 4 wheel drive truck has ran a 14.56 stock, as is just let the rear tires down to 20 lbs. put it in drive and hit the gas. If there was no electronics between the gas pedal and the throttle the truck would shred the tires at the slightest tap of the foot.
That engine is out of the LS league. The whole truck is overbuilt. 2 Tundra 6 speed auto tranys have made it to one MILLION miles and Toyota bought the trucks back.
GMs transmission's are garbage in comparison. On the road, very few vehicles, cars or trucks have more passing power. I work nights with a long straight drive home, more than one new Camaro has slowed down to a 20mph roll and hit the gas next to me. By the time I am in 4th gear they are gone and do not want anymore.

We are all dancing around the facts here and even stranger is ignoring them altogether. If your truck is hosing LS powered camaros it will more easily dust a traditional Pontiac powered camaro. Fact is the LS is eons ahead of the old stuff we are attached to. Pay me now or pay me later but I'm still getting paid.