[HWYSTR455]

Well. First of all, no engine across diff manufacturers are going to perform 'the same', they are all a little different in different ways.

But. When you talk power, torque, and efficiency, that all can compare. It boils down to basic physics, bore, stroke, flow, tune, etc.

So you can't lump all 'LS' engines together, there are a variety that are all different from one another.

If you base it on power per CI, yes, you can come very close or exceed the power of an LS with a Pontiac, with the only areas that will be difficult to compete with are head flow/design, overall design, and engine management.

You can match or exceed most of those areas except pretty much the head performance. For the LS, the entire intake tract is 'tuned' for a particular 'range'. Countless hours of design has gone into it, to the likes DIY-ers just can compete. Professional builders, with some of the 'tools of the trade' can get close, but the number of hours of testing and refining is not cost effective for people with less than billions of dollars to throw at a particular engine/combo.

So if you look at the LS 5.7, 6.0, and 6.2, factory power numbers are like 345hp-404hp, until you get into forced induction models. How is that so far off from a Pontiac 400? We've been doing those numbers for years. You want more? Go to a 455, or a stroker. The forced induction LS models are like 550-640hp, and strokers are doing that without forced induction.

Too much LS hype. And don't mention cost. People think you can go to the junk yard and grab a truck LS and blow everything off the street. Nope. You think you can get a forced induction LS engine cheap? Nope. Call a local salvage yard and ask what they will sell one for, I think you will be surprised.

Crate LS engines? Bare 'replacement' engines are $7500-$9500, before you get into electronics. Connect & Cruise packages? Start at $13k, and go over $30k. Oh, you want a 'performance' LS engine? You can't touch one for under 18k, the ones you 'want' are in the 20s, if not 30k ranges. Shoot, most here won't even spring for good rods or pistons on a $7k build, much less a roller cam.

Dependability? 90% of that is human error or failure to properly build supporting systems. Period. You go through a Pontiac, build the drivetrain, suspension, and supporting systems properly, which you would need regardless of what engine you put it, and you will have comparable reliability. I've done it. And have crushed a lot of new muscle. I can spend half as much as new muscle and outperform with a Pontiac engine. And an older platform.

Don't get caught up in the hype. LS-Fest? It's a big Chebbie advertisement. All the mag-rags? Guess who supports them with advertising? The big three. You can see it just by looking at what's gracing the pages.

Total cost of ownership. So for example, you buy a new $25k car, over 5 years, do you know what that car will cost you? Like $40k. If you had 40k to dump into your pride and joy, what could you build. You could drive that for 5 years, and sell it more than the $25k car you bought which is now a paperweight.

So many poor comparisons, and propaganda, THAT'S what's driving the whole LS crazy.


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[JLMounce]

Originally Posted by HWYSTR455

So many poor comparisons, and propaganda, THAT'S what's driving the whole LS crazy.


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This. So much this.

You want a 525 hp hot cam LS?

https://www.gmperformancemotor.com/parts/19370413.html

9 grand...WITHOUT electronics. Add a couple grand for the engine management system of your choice

I had a 455 in near new condition. I purchased KRE D ports, a moderate roller cam and a FiTech system. All in about 6000.00 for similar performance and reliability.

[RocktimusPryme]

Originally Posted by JLMounce

This. So much this.

You want a 525 hp hot cam LS?

https://www.gmperformancemotor.com/parts/19370413.html

9 grand...WITHOUT electronics. Add a couple grand for the engine management system of your choice

I had a 455 in near new condition. I purchased KRE D ports, a moderate roller cam and a FiTech system. All in about 6000.00 for similar performance and reliability.

See I feel like that is propaganda and an unfair comparison. Crate motors are always going to cost more. There are tons of dudes out there these days following the sloppy mechanics formula make crazy power on basically stock short blocks. If you want to say that comparing a junkyard Gen III to a rebuilt Pontiac isn't fair, okay that's a fair point. But so what, re-ring it. have new valve seals put in. So now whats your cost? 3500 bucks? Conservatively probably. I could still fire 3 or more bullets compared to my motor, which admittedly was on the high side of the budget for a street/strip build.

I don't have any idea what I would put it in, but I have gotten real close several times do buying a 5.3 and putting together a turbo setup, just because how do you turn down 800+ horsepower for that cheap.

I just watched the 8s for 8 thing where a dude went 8.70s for under $8k. Im not as old as some of you guys but I am old enough to remember when 12.9 seconds was supposed to be fast. Its not really anymore. And a lot of that has been driven by how capable that late model GM powerplant is.

FWIW obviously I have a Pontiac. So its not like Im a hater here. I just think Im a realist, and I find myself defending things I don't really care about that much. As has been documented in this thread, the gen III+ stuff took the best from 70 years of pushrod motor design. The result is a better product.

[JLMounce]

Originally Posted by RocktimusPryme

See I feel like that is propaganda and an unfair comparison. Crate motors are always going to cost more. There are tons of dudes out there these days following the sloppy mechanics formula make crazy power on basically stock short blocks. If you want to say that comparing a junkyard Gen III to a rebuilt Pontiac isn't fair, okay that's a fair point. But so what, re-ring it. have new valve seals put in. So now whats your cost? 3500 bucks? Conservatively probably. I could still fire 3 or more bullets compared to my motor, which admittedly was on the high side of the budget for a street/strip build.

I don't have any idea what I would put it in, but I have gotten real close several times do buying a 5.3 and putting together a turbo setup, just because how do you turn down 800+ horsepower for that cheap.

I just watched the 8s for 8 thing where a dude went 8.70s for under $8k. Im not as old as some of you guys but I am old enough to remember when 12.9 seconds was supposed to be fast. Its not really anymore. And a lot of that has been driven by how capable that late model GM powerplant is.

FWIW obviously I have a Pontiac. So its not like Im a hater here. I just think Im a realist, and I find myself defending things I don't really care about that much. As has been documented in this thread, the gen III+ stuff took the best from 70 years of pushrod motor design. The result is a better product.

https://butlerperformance.com/i-2448...tegory:1267471

Engine which will have similar power and will also need the induction system. Gonna be a pretty close wash when compared to that GM crate LS.

You can start comparing these things all day and if you do the same. Junk Yard LS, or you find a used 400/455. Machining costs will be nominal. Everything you have to buy for the pontiac, you have to buy for the LS.

Every time I've ever looked at it, it's six one way, half a dozen the other.

[HWYSTR455]

Yup.

EDIT: Actually, it's more for an LS build. Like I said, you don't get a 'true' performance engine with the GMP crate engines, still need electronics too.
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[RocktimusPryme]

Originally Posted by JLMounce

You can start comparing these things all day and if you do the same. Junk Yard LS, or you find a used 400/455. Machining costs will be nominal. Everything you have to buy for the pontiac, you have to buy for the LS.

Every time I've ever looked at it, it's six one way, half a dozen the other.

This is where our disagreement is though. I DONT think you have to do all the same things to the newer shortblocks. You can, and its better to do so, I wouldn't argue that. But also, I think there is enough evidence of dudes running factory short blocks now that it wouldn't bother me that much to do the same thing.

I would feel at least marginally confident just re-ringing a used LS block. Maybe bearings. But otherwise all OEM parts. I wouldn't feel the same about a junkyard 400. You are always gambling with used parts, but I think the gamble is way less with a newer motor.

[Formulajones]

Originally Posted by RocktimusPryme

This is where our disagreement is though. I DONT think you have to do all the same things to the newer shortblocks. You can, and its better to do so, I wouldn't argue that. But also, I think there is enough evidence of dudes running factory short blocks now that it wouldn't bother me that much to do the same thing.

I would feel at least marginally confident just re-ringing a used LS block. Maybe bearings. But otherwise all OEM parts. I wouldn't feel the same about a junkyard 400. You are always gambling with used parts, but I think the gamble is way less with a newer motor.

Correct. Agree and to take that further, this is where that thinking is flawed. Where are people going to find a 60 year old used 400 that's in good enough shape to do the things people are doing to current used LS engines??? You just aren't. Doesn't happen these days.

The whole reason LS engines are being bought and retrofitted is because they aren't that old, low mile examples are everywhere, and it's cheap and simple to buy and plunk in, add a few performance parts and you're on your way. That doesn't happen anymore on a production engine that's been out of production for the last 40 years people, lol.

[RocktimusPryme]

Originally Posted by Formulajones

Correct. Agree and to take that further, this is where that thinking is flawed. Where are people going to find a 60 year old used 400 that's in good enough shape to do the things people are doing to current used LS engines??? You just aren't. Doesn't happen these days.

The whole reason LS engines are being bought and retrofitted is because they aren't that old, low mile examples are everywhere, and it's cheap and simple to buy and plunk in, add a few performance parts and you're on your way. That doesn't happen anymore on a production engine that's been out of production for the last 40 years people, lol.

Good points, you could argue that the LS motors just by virtue of being newer are going to have a better shot in used condition. There is also that oils are way better now, so they got that benefit during their life.

[HWYSTR455]

The 455 block based short block kits with forged internals are $5050 with main caps:

https://butlerperformance.com/i-2553...tegory:1234783

So like $2-2200 more for an IA2. You still get a little bit of a savings.


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[pastry_chef]

Originally Posted by HWYSTR455

If you base it on power per CI, yes, you can come very close or exceed the power of an LS with a Pontiac

What is the highest N/A HP per cube Pontiac V8?

[HWYSTR455]

Originally Posted by pastry_chef

What is the highest N/A HP per cube Pontiac V8?

Factory? 470hp I believe. 70 GTO/GP 455? Just going off Wallace head chart:

http://www.wallaceracing.com/head1.htm

Strokers? you can fall off a log and make over 500. Most range in the 550-620 range depending on how it's cammed, etc.

GM plays with the numbers on the LS engine. For example, usually, in-car numbers are rear wheel, flywheel for 'crate' engines.

As for 'performance' LS crate engines, I don't think the GMPs are really that 'performance' oriented. People like MAST are more like actual, true performance engines. Costs?

https://www.mastmotorsports.com/collections/ls-engines

Keep in mind that is for engines only. No electronics, no supports systems or transmissions, like the GMP 'Connect & Drive' offerings.

https://www.gmperformancemotor.com/category/CC.html

Just to say, some are having issues with the connect & cruise stuff, first, they are dirty, like all GMP engines are. Personally, I would tear one down and clean them up, inspect, before I put one into service. One friend has a 69 Camaro, he is on his 3rd engine in a fairly short period of time.

FormulaJones - Used, yeah, not many IA2 or MR blocks for sale used, but people keep them until they can't be rebuilt anymore, though not sure how that compares to LSX blocks, not sure of production numbers on any of those, but bet there's not many used LSX blocks out there for the same reasons. There are still making them though. Hard to say.

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