That camaro doesn't have an LS based engine. It's got a 90's LT1 which was a half assed attempt by chevy to spruce up the SBC. They were mostly shit and don't really have an advantage over the SBC once you replace all the shitty parts with good parts which are more expensive than SBC stuff since nobody cares about the shitty 90's LT1 garbage.

Whoops I thought it had been modern LT swapped. I wonder how they were able to get it to live with a stock block?

Heck, that's got to get getting almost into billet block territory.

Computer design.

There's a reason why I gave the time period I did: the Cleveland heads are the only exception to that and are THE head which pretty much all modern OHV heads are loosely based on with cant/angle of the valves.

Cleveland gave birth the Yates heads, which I would argue inspired the LS heads, and a direct lineage to the LT/Godzilla heads.

However, they were specifically NOT in production when Honda changed the game and are not a SOHC/DOHC, pent-roof, center plug head obviously.





Nice straw-man, in fact this is exactly what I expected when I wrote what I did (albeit from the guy I was quoting).

High flow rates in heads and intakes hurt low speed torque production due to lack of velocity for cylinder filling

You've completely ignored Cross Sectional Area and that really undermines everything you've posted.

Since Ford uses nice round numbers and you brought them up for some reason:

5.0 HO (1995 cobra): 250HP @ 4800rpm, 320ft-lbs @ 3500.

GT40 heads, 145cc Intake runners, 225cfm @ .500" lift


5.0 Gen 3 Coyote: 400HP @ 4800rpm, 380ft-lbs @ 3500

M50B heads, 205cc Intake runners, 310cfm @ .500" lift


Same displacement and apparently heads that won't work for you because they are too big and flow too much.

HP per liter is only useful in bench racing and purse swinging

Oh you mean like a thread labelled How did they get so few HP per liter in the 90s?



Most boomers don't want to believe Honda started the 90s horsepower wars, but they absolutely did.

Detroit had sat on their ass content with what they had since the gas shortages started . . . really sad to read the Hot Rod magazines of the 60s and see what the automakers were floating. OHC hemis from Chrysler, SOHC/DOHC windsor motors, etc.

Realistically, we've always settled for mediocre up until recently. Harry Miller and Fred Offenhauser revolutionized a lot of the stuff that is commonplace today in the 1920s and Detroit never adopted it meanwhile Ettore Bugatti ripped off the Miller and Europe became the battleground of the small displacement, high RPM, DOHC, supercharged, etc stuff.





Exactly ZERO of what you wrote matters.

In a thread asking "How did they get so few HP per liter in the 90s" the answer was, and still is, the cylinder heads were trash because Detroit didn't care until other automakers started not settling for crappy ports in an iron casting.

Domestic mass production cylinder heads were sufficient for their time.

Could they have been better? Yes, but that's what port work or aftermarket heads are for.

And before you say an engine that needs those is trash, consider that those are likely to be necessary as part of a serious performance build even on the latest and greatest engines.

There's probably a whole Bosch Automotive Handbook written about this that explains it in great detail.

You no longer have cap & rotor so much more accurate firing, single point fuel injection -> multi-point injection -> sequential point injection -> Direct Injection, mufflers and manifolds are engineered better for less back pressure and better breathing, less drag and resistance from better engineered drivetrains, change in viscosity of lubricants, refined and lighter transmissions with less drag coverting more energy to motion, undercarriages that are engineered to be smoother with less drag and wind resistance, tires with less rolling resistance, etc.

Lol, my 2.8 liter Toyota diesel is making 90hp.  It's the "upgraded" model.

I remember when my boss purchased a brand new 1996 Dodge Avenger
The 2.5 liter V-6 made a whopping 160 hp. It was dog slow, 0-60 in 10.2 seconds.

1996 Avenger 2.5 liter - 160 HP
2006 Accord V-6 3.0 liter - 240 HP
2016 Accord V-6 3.5 liter - 278 HP

Clearly big gains really happened in the early 2000s. It's also when GWB was president. Coincidence?

1978 mustang Ii
- 302W
- 2bbl carb
- crappy heads/valves
- crappy exhaust
- crappy cam and ignition
- smog shit setup
- 8.2:1 compression
140hp

1988 mustang
- decent heads
- decent intake
- decent cam (roller - hydraulic)
- electronic ignition and engine mgmt (ok)
- decent exhaust
- 9.2 compression
- 215hp

2019 mustang
- more compression
- more valves
- more computers
- more sensors
- more to go wrong
- 400+ HP

Also tighter tolerances and better built along with better components that technology makes more readily available.

I have worked on all 3, the fox body 302 was and still is my favorite.

F1 gets 850-1000 horsepower from a 1.6 liter V6.  

5.0 Coyotes were just over 4.95 liters before 2018 and are just over 5.03 liters after 2018.

Don’t waste your time on the “my buddy says” dude with multiple personalities. Attached File

My friend's dad bought a used 1980 Corvette. It came from California.   (Meaning that instead of the anemic 190 HP motor, it had an even more anemic 180 HP).

Once my friend was allowed to drive the thing, he took me for a ride. I remember hitting one long straight stretch of highway and saying "Floor it!"

A few seconds later, I turned to my buddy and said "Come on, floor it - we have plenty of open road!"

He said "It is! It's been floored for the last 10 seconds!"

And yet you could make 900+ HP through a carb with 400+ cubes today thanks to modern heads?

A carb can be really good at what it does to make HP.   EFI just helps make the engine behave at all RPMs and barometic pressures.


There is a really cool video I watched last night on my rabbit hole youtube journey where they went to Roush/Yates.   They talked about the #5 cylinder consistently losing springs due to likely not seeing enough oil during high G forces of ovals.

They also talked about harmonics and firing order with Roush playing some games back in the day.  

Then they talked about how due to harmonics they found problems if they tried to equalize the HP per cylinder while trying to make them all equal, I guess the harmonics said "naw fuck that" if you tried to make them equal and shit started to break in new ways

There is some wisdom in the cylinder drawing what it needs/wants from a Carb.    There are a lot of assumptions being made even with sequential fuel injection unless you put EGT sensors on every header tube, which for some racing genres I can see being a thing.

YouTube "GrubWorm Camaro"

I'd take the 88 with an all aluminum block/head , vvt . A-arms up front would've been nice ....panhard out back ...lsd
*LS3 , t56 , sn95 new edge ,panhard , lsd ....or LV1/3, t56 , panhard , lsd

Ford used the 4.9L nomenclature on the 300ci inline six.

Not quite as smart about this as you think you are.

1. Coyotes have two things that were not economically or technologically viable in the 1970's and '80s - First: Long ram tuned intake runners, optimized for lower speed cylinder filling, that have been enabled by plastic intake technology and advances in casting for the handfull out there that are still all or mostly aluminum. Don't even bother whining about Chevy TPI intakes or Ford's folded 5.0 design, because you'll be wrong again. Those older tuned intakes had far shorter runners and only worked well with relatively restricted heads. You can find ram tuning calculators easily on the internet, and you will find it takes a much longer ram than you might think to optimize for daily driveability. Long rams were always easier on inline engines, but a huge challenge on V engines until plastic intakes came along. Second - the Coyote uses variable valve timing to aid low speed cylinder filling, something not available in the 1970's and 1980's. EDIT - forgot that Coyotes also have variable runner control on their intakes to further aid low speed cylinder filling,

2. Physics - cross sectional area and flow rate are inextricably linked, but also not the only two factors. If you don't understand this, I can't help you. Any high flow head will have lower port velocities - resulting in less efficient fuel atomization (in the absence of DI) and less tumble in the combustion chamber, also leading to less stable combustion. The entire premise of the Honda CVCC head was to overcome these combustion issues with a smaller prechamber. The juice obviously wasn't worth the squeeze, or CVCC would still be with us. As a Honda worshiper, you should know this.

3. No one outside of a handful of SoCal ricers gave a crap about what Hondas were making for HP in the 1990's. The Civic made a cheap, available hotrod platform, that was all. HP had been on a steady climb across the industry since the low water mark in 1980, and that is irrefutable fact.

4. Yeah, Miller and Offy did a lot right, but they also didn't have to meet a price target or much of a durability target, and neither did Bugatti. As I noted above, post-WWII Europe taxed cars on displacement, so it their move to small displacement high revving engines was forced, not what they wanted to do. The EU gave up on superchargers outside of a few isolated instances by the 1950's. The main driver for turbo tech in Europe were the tax advantages of diesel engines (rally homologation was a secondary driver for SI), driven largely by the fact that the big EU oil companies (Total, Shell, etc) had more diesel refining capability than gasoline capacity. EU socialist governments have always worked closely with their big, closely held companies, but that's another rant. Even so, TDIs didn't really become a thing in Europe until the late 1980's. Ever drive a non-turbo 240D? You would wish for a '79 B210 if you did.

GM was figuring it out in '96. This is a neat book I have that shows you how to turn a 4.0l Olds Aurora motor (Northstar  like) into a
650 horsepower, 10,000 RPM IRL, monster. Olds won a bunch of races with it and even sold it as a complete unit. I always wanted to see someone stick it in a DTS or stock Aurora.

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Watching one of the stick shift races, they mentioned no longer using a stock block.

I'd like to see that as an aluminum block/head , forged steel crank , LT4 head , vvt , DI/port injection , piston squirters, 12:1 cr

* Lay it down at 30° ...slant6

It is on YouTube somewhere.

https://www.motortrend.com/how-to/300-ford-inline-straight-six-with-ls-head-engine-build/

Neat

Valve springs have the hardest life in almost any engine. There ARE frequencies in which springs will resonate leading to float/bounce and deformation hence why the manufacturing has gone to conical/beehive springs in addition to cutting mass given not all of the spring is active mass.

Dr. Gary Patterson is really on the leading edge of a lot of this. Anything he puts out along with his co-hort, Dr. Andrew Randolph is worth it's weight in gold.





I can see why you are a former "powertrain" engineer when you immediately hone in on specifics that are barely half-true while ignoring why I am typing what I am typing: the broad and easy answer to the thread title I've already stated.

It's not computer management nearly as much as it is cylinder head development. I don't care what appeal to authority or whatever other logical fallacy you want to resort to. The single largest restriction on any ICE engine should be the valve/valves. Detroit didn't care about this fact until they were forced to by competitors as evidenced by the abysmal flow rates of almost all domestic v8 heads until the mid 1990s. It was only until "high-flowing" heads showed up on grocery getters with small cams eating the Big 3's lunch that they realized they needed to follow the racing development and flatten the valve angles out, cant the valves, raise the runners, and increase MCSA around the guide all resulting in cylinder heads that flowed way WAY too much for you to deal with apparently.




That is so completely wrong that really no one should ever take anything you write in this thread seriously.

The ports in the coyote head are ~40% bigger that a GT40 head. They flow ~35% more cfm AT A MINIMUM everywhere.




A. It's joke that you keep referring to "low speed cylinder filling" while simultaneously trying to discredit "high flow heads". How efficiently do you think the cylinders would be filled in "low flow heads"?

I am well aware of the work Gordon Blair pioneered in the 60s in sonic wave or pressure wave tuning. You're trying to claim 2% of the equation negates the 90% part of why 90s motor sucked compared to today's.


B. Saying plastic allowed for longer runners is ludicrous. PACKAGING is what makes very long runners difficult. There's not a performance intake on the market that comes even close to the length of the MOPAR cross ram and even then you don't want that if you care about HP.

Why don't you tell the class what you define as "long" and "short" runner and then tells us what the runner length is for a GT40 5.0 and a Coyote 5.0


C. Length doesn't matter near as much as when your heads are sucking through a straw.

You are arguing for a one-hit wonder with a peak torque value at like 2800-3000RPM and then complete dog shit everywhere else. Average HP AND Torque will be higher in a bad ass head with valve timing events (specifically wider overlap, less duration and higher lift) and more "normal" runner lengths.



Complete bullshit.

A. You haven't defined the terms
B. Bernoulli's principal is at play here and you keep ignoring it

Velocity is a function of Pressure and Volume. You've not once mentioned airspeed here and why would you? Anyone could read right through the lie you are promoting given the basis that higher flow can AND IS achieved with higher port velocities through better port shape, closer minimum CSA to average CSA, and valve seat geometry.



The dumbest and most boomer thing you've posted. Pretty much have to call BS on your alleged "powertrain" involvement here. Maybe, if we're lucky, we'll get some story about your 3/4 cam and glasspacks while you were leaving ricers in your dust with your billy badass '67 whatever.

The Big 3 were content with mediocre gains until 1.6-1.8L came along that could take 15-20psi of boost, make twice the HP as 300-350 cid v8 and get twice the gas mileage doing it.

It was only because of the competition that they realized they needed to get serious about cylinder head development.

Huh?

I work at an independent Porsche shop that specializes in air cooled. So a lot of my "buddies" are Porsche people. One of the shops where friends will come by and just hang out.

Is this about my antique crack? I'm sorry. I didn't mean anything by it. I love Stutz. He's a great guy and super knowledgeable. I was only funin'. He's IMed me about some old Indian stuff before.

7-1 compression pistons, valve heads the size of dimes, a two barrel carb with intakes the size of a dime, cam lobes that are round with just enough lift to get fuel in the chamber, ECU's programed by the EPA.

In 90s Japan there was a "gentlemen's agreement" by all automakers to keep cars under 300 hp at the crank.  On paper they did, but in real life they had more HP.

Not knocking you at all.
The poster you had quoted with gal in the username is constantly talking about a buddy with the “my buddy says” bullshit.

It started in the early '70's. A friend bought Cadillacs from a dealer that also sold Corvettes. The dealer got a pristine '73 Corvette 454/automatic in trade from a doctor. Took the GF and went for a test ride. Let if warm up a bit, told the GF "hang on", and mashed the throttle. It was impressive for the lack of power! It eventually picked up speed but no big-block fury like I expected. The small-block L82 'vettes at least felt like they were fast even if they really weren't.

"Ever drive a non-turbo 240D"

I did! Put a clutch in one for a friend. Took it for a test ride and thought "what a slug". Had a hard time getting up to speed on a freeway on-ramp.

IIRC, there is/was some agreement to speed-limit cars and motorcycles to 300KPH/186MPH. On bikes, they did it by limiting RPM in top gear. Plug-in aftermarket black box would tell the ECM that the trans was in a lower gear and allow the engine to go to redline in top.

This.

Both appear to have some real knowledge, yet this seems to be the chosen method of sharing.

Weren’t transmission option something of a limiting fact in the 80s as well? I thought the 700r4 was pretty much as good as it got for GM at the time, which to me wasn’t very good. And my 82 Trans Am had a warmed over T-10 that was junk, while my 84 Firebird had the T-5 at least, but it was still about at its limits with the 5.0 or the GM L69 HO motor, or so it seemed at the time. HP/torque is moot if it cannot make it to the pavement.

In the early 1990s I had a 1/2 ton 4wd chevy pickup with the 4.3 V6. I believe it had some kind of throttle body injection. It was rated at 150HP and towing a 2400lb boat it was adequate
but not stellar. As I remember it got 15-16mpg mixed driveing and on a highway trip could sometimes get 18mpg.


I now have a 2021  1/2 ton 4wd with the 4.3v6 that is rated at 283HP . night and day different truck and it gets 20mpg mixed and can sometimes get 21+mpg on the right highway trip.

Now the base engine in chevy 1/2 ton is some kind of V4 turbo which is something like 2.7? liter. On paper it has more HP than my V6 but I was scared being as how at the time it was the first year for that engine. Not even sure if the 4.3v6 is available at this time.

Hot rodding was a thing for a few generations before the 80s "malaise" period . It's almost like we're in a new malaise period of different parameters. Computers have made power easy but cars as a whole are largely disposable. Planned obsolescence. On top of that you have the unelected bureaucracy laying down so much red tape as to make any efforts become unaffordable . Cash for clunkers took out a lot of candidates and drove used prices up . Market forces vs bureaucracy.  Interesting to contrast the Carter/Reagan years vs present . I thought these ecoboost engines were interesting at first ...they just seem like little grenades now . The inline sixes coming back out ...but they're doing weird stuff with the timing belts . I just long for simpler times.

Scoggins-Dickey is getting 644hp-7×× ft/lbs with a stg2 cam and 14.5lb boost out of the LV1/3.

my dad turned me loose with a 1974 454 vette when i was 12 because he figured i couldn't hurt myself.  

he was right, of course, but i drove that fucker around in circles on our property every time i got the chance.  

at the same time he also had a '68 427/435 that i wasn't allowed to touch...

Wrong. The Honda scene was huge across the whole west coast. Remember “Fast and Furious” that came out in 2001? It was like that.

goddamned hippies and their peace and love shit...

They made up for anemic power by being incredibly unreliable.

Japanese 4 cylinders forced Detroit to hugely improve its 4 cylinders, but they weren't really a threat to larger engines until the excellent Honda K motor came along in 2001.

Before that, modding a Japanese 4 to make any real power was pretty involved and expensive, and you rarely saw one making making more than 400 crank horsepower even on a serious build largely thanks to block strength limitations.

That's no longer the case because of decades worth of aftermarket offerings and knowledge in strengthening the blocks, but that's now not the '90s.

Not a boomer, but don’t underestimate what the ICE geniuses were accomplishing with the tech they had in the ‘60s. The Ford 427 Cammer, as an example, was over 650hp, and we all know what the Hemi guys were doing.

The tech below is 1966 and 1967, respectively. On the left is 485hp/200mph and next to it is a 625hp Tunnel Port. Care to guess what these cars weigh?

I don’t understand the need to compare modern tech to classic tech. The engine on the far right is 805hp, so what? Do you want to compare the 40hp engine in the bottom photo as well?

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Agree
The late C3s were peak Corvette.

Pete Aardema was doing cool stuff with ohc heads on small blocks