Dazed and Confused SD 455 [Archive] - LS1 Performance Information

iLIKEtransAMS

11-15-2006, 12:53 PM

Agreed. The size of one 454 cylinder head is literally the size of two Poncho cylinder heads. Pontiac made great, big cubed, engines back in the day, but they sadly can't compare to the Chevy big blocks...

i may just be ignorant, but i don't think that an ls6454 could take down an SD 455, if the 455 has been appropriated wi/ good heads, intake, etc. to pre-emissions cracking down, especially b/c the SD455 not anything like a regular 455, but based off of a nascar racing engine... but that's just me. :flex:

Zboner

11-15-2006, 12:59 PM

his was a LS5 not the LS6 in the movie it clearly reads 390 HP, and his was modded also, with 11:1 comp .30 over, intake, double pumper and 4.11 gears

Street Lethal

11-15-2006, 01:55 PM

i may just be ignorant, but i don't think that an ls6454 could take down an SD 455, if the 455 has been appropriated wi/ good heads, intake, etc...

No doubt that any engine can benefit from a nice build-up, but the reason in which why I would go with a big block chevy over the Poncho, is mainly because of the cylinder heads. Any engine over 400 cubic inches can be considered as a "torque monster" (which is what Poncho's were commonly referred to as, back in the day)...

But remember that true power is found in the cylinder heads, and the potential of the 396-402-427-454 cylinder heads, due to their literal size, makes them umatched (horsepower and torque level wise), accept when your comparing them to the mighty Hemi, of course..... ;)

The Scientist

11-15-2006, 04:23 PM

"Donny, you better have your wood screws in...cause im gonna blow your doors completely off!" :rotfl:

iLIKEtransAMS

11-15-2006, 08:37 PM

No doubt that any engine can benefit from a nice build-up, but the reason in which why I would go with a big block chevy over the Poncho, is mainly because of the cylinder heads. Any engine over 400 cubic inches can be considered as a "torque monster" (which is what Poncho's were commonly referred to as, back in the day)...

But remember that true power is found in the cylinder heads, and the potential of the 396-402-427-454 cylinder heads, due to their literal size, makes them umatched (horsepower and torque level wise), accept when your comparing them to the mighty Hemi, of course..... ;)

Gotcha:)

05gtoautoX

11-19-2006, 06:51 PM

I disagree with street lethal, The sheer size of the head itself means nothing, the valves can only be as big as the bore allows,the rest of the head such as the ports can only be ported so much until you reach antifreeze, so the literal size of the head does nothing, but IMHO absorbs heat. Pontiacs also have a very long stroke, which through mechanical leverage produces massive amounts of torque, especially on the low-end. And I disagree with him saying any engine over 400 cubes can be considered a "torque monster" a SBC400 has it's fair share, but by no means is it considered a torque monster,(one example). Pontiac was making as much torque with their smaller displacement engines as everyone else was with their big blocks. To say a 73 T/A with a 455 S.D. could not beat a 70 LS-6 Chevelle, is very dependant, especially on driver, final drive ratio, transmission etc. But in a honest, everything being even race, Ithink it would be very close.

Raoul-Duke

11-20-2006, 06:54 AM

we know the chevelle was modded....and i don't think that ta was ever stated modded or not?

Gleomyr

11-20-2006, 01:09 PM

I am sorry to have to disagree with so many of you but I would have to think that the Pontiac Trans Am SD-455 is one of the greatest cars/engines of all time.

First of all stock the SD-455 was rated at 290hp because in 1973 Pontiac put regulations on their cars making it so that all cars had to be producing 300hp or less. In reality the stock SD-455 was producing 371hp SAE NET. This 371hp figure is however still a truncated number. The original SD-455 produced well over 500hp (due part in fact that it was hand assembled with extreamly low tolerances and based on Pontiacs NASCAR engine design from the '60s...) but they put an inhibitor plate on to reduce the power so it could pass Pontiacs policies and emissions. One of the greatest things about this engine was it was so easy to return to its original 550+ hp form... just drill out 3 rivets, remove the plate, and voila!

So even when it was completely stock with the untampered with 290hp the SD-455 was still able to rocket the 3,504 lb Trans Am down a quarter mile stretch in 13.54 seconds at 104.29 miles per hour as reported in Hot Rod magazine in the June 1973 issue. Thats faster than any stock version of the Corvette until Chevy brought us the $60,000 ZR-1 in 1990... Thats 17 years of complete dominance!

Given all this, I would have to put my money on the SD-455 anyday.

iLIKEtransAMS

11-20-2006, 02:15 PM

Gleomyr, that's what im F***in talkin about man, the SD-455 was a BEAST just waiting to be unleashed, at least you know what I was talking about when I said it was based off of a NASCAR engine in a previous post. :flex:

im glad someone agrees with me b/c no one was giving the SD enough credit and im really too passive to fight with these guys who like their ls6 454 (not that I don't like the ls6 454, just not against the SD 455)

snaggeltooth

11-21-2006, 12:13 PM

I think it is because most people dont know much about the SD 455 , or PONTIACS for that matter ...

Street Lethal

11-21-2006, 01:01 PM

I am sorry to have to disagree with so many of you but I would have to think that the Pontiac Trans Am SD-455 is one of the greatest cars/engines of all time...

You are mistaken. I don't think any true enthusiast would ever dismiss Pontiac's engine lineup...

First of all stock the SD-455 was rated at 290hp because in 1973 Pontiac put regulations on their cars making it so that all cars had to be producing 300hp or less. In reality the stock SD-455 was producing 371hp SAE NET. This 371hp figure is however still a truncated number. The original SD-455 produced well over 500hp...

Remember that we're talking about a giant air pump, and that's all. No magic involved. Since you mentioned the factory restriction plate, I take it we're not arguing factory ability, in which if this is the case, it is clearly no longer in Pontiac's favor. No Pontiac engine will ever have a chance in making more power up against any similarly worked Rat engine, period. End of discussion....

So even when it was completely stock with the untampered with 290hp the SD-455 was still able to rocket the 3,504 lb Trans Am down a quarter mile stretch in 13.54 seconds at 104.29 miles per hour as reported in Hot Rod magazine in the June 1973 issue...

Well, as currently being reported through Hot Rod magazine, the F.A.S.T. class is where everything counts now in reference to 55-74 muscle. In fact, the first muscle car in the tens was, you guessed it, a '69 L88 vette. I highly suggest picking up a copy of the December '06 print, titled; "World's Fastest Muscelcars, Finally the Proof"....

Thats faster than any stock version of the Corvette until Chevy brought us the $60,000 ZR-1 in 1990... Thats 17 years of complete dominance!

Do you hear yourself? The L98, for example, was very heavily restricted by the factory, probably even more so than the SD-455. However, with the simple installation of the Holley Stealth Ram onto that motor, your now running similar numbers to that of the stock SD-455, with, not to mention, 100 less cubic inch displacement. Seventeen years of "Dominance"? Not likely...

Given all this, I would have to put my money on the SD-455 anyday.

You'd lose... ;)

snaggeltooth

11-21-2006, 06:36 PM

Remember that we're talking about a giant air pump, and that's all. No magic involved. Since you mentioned the factory restriction plate, I take it we're not arguing factory ability, in which if this is the case, it is clearly no longer in Pontiac's favor. No Pontiac engine will ever have a chance in making more power up against any similarly worked Rat engine, period. End of discussion
I know you have alot of love for your engines and all ... but boy are you off on that one ...

Street Lethal

11-22-2006, 04:31 AM

I know you have alot of love for your engines and all ... but boy are you off on that one ...

Will you ever be elaborating as to why I'm off? Or will you simply continue with this; I'm right, your wrong method? :D

I have nothing but love for Pontiac engines, and have owned quite a few 400's in the past. Great torque motors, just like the rest of the BOP engine configurations. Heck, even the Caddy 472-500 engines were great performers, when built properly...

However, how is it possible for the Poncho engine to dominate a Chevy Rat motor? An explanation is in order, not some theoretical fluff. The Chevy block itself can be bored out more than the Poncho because of it's literal size (more cubes = more torque), the heads themselves will always be able to flow more than the Poncho because of their literal size (more flow = more horsepower)...

So, exactly how is it that the Pontiac can possibly dominate a Chevy Rat? Kindly explain yourself this time... ;)

Street Lethal

11-22-2006, 05:18 AM

I disagree with street lethal, The sheer size of the head itself means nothing, the valves can only be as big as the bore allows...

No kidding, and how much more can the Pontiac engine's block be bored out to compensate for much larger valves? Now ask yourself, how much more can the Chevy Rat's block be bored out to compensate for much larger valves? Quite a difference there, don't you think....? ;)

...the rest of the head such as the ports can only be ported so much until you reach antifreeze, so the literal size of the head does nothing.

Really? Show me the best aftermarket Pontiac head that flows better than the best aftermaket Chevy Rat head? Have you any idea of the actual CFM ratings that Rat's are capable of... or are you just blowing smoke?

In reference to hitting antifreeze, lemme tell you, the Pontiac head has more of a probability of hitting a coolant port than any Chevy Rat head when allowing for more CFM (thus, helping to prove the Rat's superiority right there). So that was a pretty irrelevant comment. Every head has it's limitations, but the Chevy Rat, clearly, has a tremendous advantage over the Pontiac's because of it's size....

Now, let's get into where it really counts. Lets talk about cubic inch displacement. There are many aftermarket companies out there that offer Poncho's, aluminum Poncho's for that matter, well into the 500+ cubic inch displacement range. Suddenly, the Pontiac's heads have now become a problem. Thinking the Pontiac will make more power than the Chevy in this respect is quite wrong, which was my original point, all along...

Bigger is always better.... ;)

Street Lethal

11-22-2006, 06:10 AM

I think it is because most people dont know much about the SD 455 , or PONTIACS for that matter ...

Is that right? I purposely brought up the Rat's cylinder head advantage.... waiting for such Pontiac enthusiasts, such as yourself, to delve into our automotive history. There have been experimental Pontiac engines in the past built that would annihilate the "Super Duty 455", as well as the "LS-6 Chevelle's", and I'm surprised that both you and the other Pontiac guru failed to embellish on them.

Being that I'm a Pontiac enthusiast, I'll gladly bring his genius to light, since you didn't. Mickey Thompson! The man offered Hemispherical heads for the beloved Pontiac back during the 60's, that sadly were dismissed. This would have been a tremendous concept for the Pontiac loyal, that would have dominated....

I know, I know, you Pontiac guru's were getting to that, right....? :rolleyes: ;)

Street Lethal

11-22-2006, 06:39 AM

And I disagree with him saying any engine over 400 cubes can be considered a "torque monster" a SBC400 has it's fair share, but by no means is it considered a torque monster, (one example)...

One example? A pretty bad one at that. Exactly which year Chevy 400 are you referring to? What were the cam specifications (in comparison to the Poncho you have in your head)? What was it's dynamic compression (in comparison to the Poncho you have in your head)? I'm getting so sick of people who imply that some type of "torque God" lived within the Pontiac engines alone. Cubic inches makes torque, period...

Pontiac was making as much torque with their smaller displacement engines as everyone else was with their big blocks...

Really? Hmm, yet, I wonder why the Pontiac "Ram Air V" project (their forgotten 303) failed to match Chevy's powerful 302 (a small block) during the pony car wars? I wonder why the Pontiac 301 failed to match the Chevy 305 (a small block)? I wonder why the Pontiac 350 failed to match the Chevy 350 (a small block)? I wonder why General Motors chose to stick with Chevy, over Pontiac... :rolleyes:

snaggeltooth

11-22-2006, 06:56 AM

the 455 SD came out in 73-74 what did Chevy have that would even keep up with it...Take you LS6 drop its compression take away the big Holley and aluminum intake .. see what you got ..

snaggeltooth

11-22-2006, 07:05 AM

And dont kid yourself the only reason GM stayed with Chevy motors was because everything was going front wheel drive except trucks and a few cars . Pontiac realy only had the Trans Am , after the bonnville went FWD ...

9T8W66

11-22-2006, 11:44 AM

Pontiac V8's were extinct long before the Bonneville went to FWD.
Chevy's became he Corporate engine of choice because it was easier to make them powerfull, economical, and emissions compliant.
How many of yu have ridden in a Ram Air V Equipped car ?
Pontiac's R/A V was a 475+ HP 7000+rpm Beast that was never installed in a factory car and it was only 400 ci. This engine could of been the equalizer but only a Handfull were built.
Pontiacs managment was making a transition in the late 60's and that is partly why they lost there dominance in the HP wars.

Comparing the SD455 with the LS6 454 is Dumb they are from 2 different Era's

snaggeltooth

11-22-2006, 01:03 PM

Street Lethal

11-23-2006, 03:31 AM

the 455 SD came out in 73-74 what did Chevy have that would even keep up with it...Take you LS6 drop its compression take away the big Holley and aluminum intake...

Snaggel, this conversation is starting to go in the wrong direction. We're both enthusiasts, and I'm trying to explain myself as best I can for you, and your taking it the wrong way. I'll try again....

I am a Pontiac enthusiast. I consider the '64 GTO to be the first muscle car, and the '79 Trans Am to be the last. Pontiac's built great motors back in their day, as I should know, I've owned quite a few Pontiac 400's, one in which resided in an '84 Camaro... ;)

The argument was in fact which engine being more dominant.... the '73/74 SD-455, or the '70 LS6-454. Well, there's little question as to which car is considered to be more powerul from the factory, the '70 LS6 Chevelle. That's not an opinion, that is fact.

Now, when you get to modifying these engines. The Rat motor wins, hands down, because of it's cylinder heads. Bigger is always better in the long run. Yes, you only really need a certain amount of air per cubic inch displacement, but flow is just as important, then there's the ever increase in cubic inch displacement....

Now, had Mickey Thompson offered his heads through Pontiac.... there's little doubt that Pontiac would have been dubbed king of them all. No question about that, as those hemisphercial heads were that good...

Also, why do you think Pontiac performance was lacking before the advent of the Ram Air IV heads offered by Edelbrock during the 90's? When these heads finally came out, it was like a breath of fresh air for Pontiac enthusiasts. We (speaking as a Pontiac enthusiast) felt like Pontiac was back on the map, believe me... :)

As for what Chevy produced during the 73/74 model year, to combat the Super Duty line-up. I never said that they did build anything... however, one could take any 73/74 Camaro, work it's 350, and contend with it, easily. This is what I meant when I stated that there's no magic involved. Any engine can be made to perform....

And dont kid yourself the only reason GM stayed with Chevy motors was because everything was going front wheel drive except trucks and a few cars...

Listen, there are a few reasons why General Motors dropped the Pontiac engine line-up, but getting into them is besides the point. I was being a tad sarcastic when I threw that part in... ;)

Street Lethal

11-23-2006, 03:44 AM

How many of you have ridden in a Ram Air V Equipped car ? Pontiac's R/A V was a 475+ HP 7000+rpm Beast that was never installed in a factory car and it was only 400 ci.This engine could of been the equalizer but only a Handfull were built...

I seriously doubt that you yourself have ridden in a Ram Air V equipped car, which would make such a claim as the one written above, fluff. Rumors and speculation. Again, all theory, and no substantiated proof...

I've heard countless stories in reference to the Ram Air V project, but never any hardcore proof. The Chevy 302 dominated the Trans Am series, while Pontiac claims that there was simply not enough time for them to develop it's 303... :rolleyes:

... excuses, excuses. ;)

Comparing the SD455 with the LS6 454 is Dumb they are from 2 different Era's...

Wrong era? They both flourished during the early 70's. I hope you don't think we're referring to the LS6 engines found in the C5 Corvette's lol....? ;)

Street Lethal

11-23-2006, 04:02 AM

Pontiac's R/A V was a 475+ HP 7000+rpm Beast that was never installed in a factory car and it was only 400 ci...

The Ram Air V was designed for Trans Am racing, and was not 400 cubic inches in displacement (your confusing it with the Ram Air IV). It would have been immediately disqualified if it was...

Ram Air V - 303;

2.5 in. (63.5*mm) journals, special "tunnel port" heads, solid-lifter version of the 400's Ram Air IV camshaft, 4.125 in (104.8*mm) bore, 2.84 in (72.1*mm) stroke, displacing 303 cubic inches...

Hurley711

11-23-2006, 05:04 AM

"That's what I like about high school girls, I get older.................they stay the same.":nana: :nana:

snaggeltooth

11-23-2006, 01:32 PM

As for what Chevy produced during the 73/74 model year, to combat the Super Duty line-up. I never said that they did build anything... however, one could take any 73/74 Camaro, work it's 350, and contend with it, easily. This is what I meant when I stated that there's no magic involved. Any engine can be made to perform....

There is my point ... You have to mod a 350 chevy ... a lot to keep up with a stock SD .. And SD you got in that car was just like a kit with only most of the parts ...

Street Lethal

11-24-2006, 04:20 AM

There is my point ... You have to mod a 350 chevy ... a lot to keep up with a stock SD .. And SD you got in that car was just like a kit with only most of the parts ...

But re-think what your saying here though. I'm not arguing if a "stock" 73/74 Chevy 350 will be able to hang with a built from the factory 73/74 SD-455. That is not my argument, as Chevy clearly did not offer anything worth while during those two particular years. We were debating the LS6-454 vs the SD-455, weren't we....? :confused:

If what you stated above though would be your case, that would be like me asking you what Pontiac offered during the '69 year to battle the COPO Camaro. Their GTO "Judge" was clearly not in it's league.... ;)

snaggeltooth

11-24-2006, 07:55 AM

That is because the COPA cars were not known to about 90% of the buying public.. The Judge was just a option you selected on the purchase sheet ,,Most of the time people bought what was on the lot.... They did not have the internet to reaseach cars like we do today.. I saw in MuscalCar mags that most LS6 Chevelle were not bought for what it was made for ... Some were bought with Auto, sometimes on the coloum, and regular rear ends ... Not cars set up to take advantage of the engines ..

Street Lethal

11-24-2006, 11:10 AM

That is because the COPA cars were not known to about 90% of the buying public...

Once again, we dance around the original argument of the SD-455 vs the LS6-454. I'm game though, let's toss the COPO out of that little scenario I mentioned, and replace it with the more common L88 vette in it's place. Better yet, lets end this thread, as I believe all points from both sides were already made... ;)

9T8W66

11-24-2006, 11:34 AM

I would suggest you guys pick up Pete McCarthy's Book Pontiac Muscle 55-79

There are whole Chapter's on The Ram Air's SD's and the R/A V's
True the 303 was originally slated to use the tunnel port heads but they found that the engine made more power with the R/A IV Heads. Still not enough to compete against the Fords And Chevy's of the times. In `69 Pontiac was also looking at the Dominating at the dragstrip so the R/A V 400 was developed alongside of the 303 Program. A 428 version was also tested with dual quad manifolds. These Engines used Blocks with reinforced webbing cast into the lifter valley (like the SD 455) and Heavyduty Forged Rods.
The projects got cancelled but alot of parts were already available. About 100 R/A V Engines were assembled and sold over the counter to Racers
An SD R/A IV Engine was slated to go into the Trans Am in 1970
It would use the block and rods from a R/A V with R/A IV heads and valvetrain
The RPO for this Engine was LS1 (sound familiar) This would have been the first of the return of the SD engine program. This also never Happened The Trans Am's received the same engines as the GTO that Year.
The SD455 (RPO LS2) was the next engine in this lineup but was sidlined for a couple years because of the EPA's mandate on compression and emissions requirements.
And yes I have ridden in a R/A V !
I personally Know Milt Shornack who was the main wrench and Driver for Royal Pontiac back in it's Hey day.
My Friend Bill Shultz Is the Owner of the `69 Turquoise and White Royal Bobcat and It Has a R/A V in it.

snaggeltooth

11-24-2006, 11:38 AM

L88 was hardly a common car being that only 115 was made in 69... Why dont you try the more common 375 Hp 396 ...
Well there was 4500 Ls6 in 70 so they are fairly common ... I guess what they would have met was the RAIV 400...
All I have been trying to say is that just because a LS6 might have outrun some Sd 455s dont mean some did not loose to them as well..

Street Lethal

11-24-2006, 12:04 PM

L88 was hardly a common car being that only 115 was made in 69... Why dont you try the more common 375 Hp 396...

"Try a more common 375-HP 396"? LMAO, so, your saying that the 73/74 Super Duty Trans-Am's (in which was in fact your original argument, not the GTO, correct?) were more "common" than the entire L88 Corvette's production? Hmm, you can argue that the Super Duty engines were that good, while I'm limited to just the 375 horsepower 396...?

I'll put up any version of Chevy's 396 against any version of Pontiac's 400, any version of Chevy's 427 against any version of Pontiac's 428, and any version of Chevy's 454 against any version of Pontiac's 455. There you go. My argument was their cylinder head design, and NOT their yearly factory displacement. Go ahead. Pick an engine, and lets continue on with this ridiculous discussion... ;)

The Chevy LS6, L88 & ZL1 engines will destroy anything that Pontiac had to offer during those years, period, end of discussion. I don't want to hear about removing restriction plates, because, as you so pointed out; "There is my point ... You have to mod a 350 chevy ... a lot to keep up with a stock SD".

Well then, please tell me, what STOCK Pontiac engine (ANY of their engines) could keep up with a STOCK LS6, L88 or ZL1 (WITHOUT MODIFYING)....? ;)

snaggeltooth

11-24-2006, 12:15 PM

since your engine choices are basically race engines stuck in a production car Ill go with the 421 SD and the 428HO....

Street Lethal

11-24-2006, 01:56 PM

since your engine choices are basically race engines stuck in a production car...

There were many great production muscle cars that were offered with race engines, including the infamous Hemi powered Dart...

The Chevy's that I mentioned are just a few. There was simply no need for Chevy to make every single one of it's muscle car's 500+ horsepower (not everyone was obviously looking for that, especially with rising insurance rates, and gas prices), so comparing Pontiac's "mighty" Super Duty's with the de-tuned Chevy production cars is, well, silly...

snaggeltooth

11-24-2006, 02:20 PM

Street Lethal

11-24-2006, 02:44 PM

I see so a Pontiac race engine dont count but a suposed 500hp + Ls6 is just you normal Chevy engine ..... And a all aluminum 427 is just a normal everyday grocery getter ...

Must be nice to be GMs golden child , when one of the other 3 BOP came out with something better than theirs they would just outlaw it ...

Well, it's now very clear that I have mistaken you for somebody else, as your responses are getting quite strange and incoherent. You seem to know next to nothing in reference to Chevy engine's, nor how GM shamelessly mis-quoted the dyno numbers due to the ever rising insurance premiums. Think the advertised LS6 was a mere 450-460 horsepower? Think again.

Your obviously dancing around the entire argument, while quoting ridiculous things such as; "when one of the other 3 BOP came out with something better than theirs they would just outlaw it". Outlaw it? What the devil are you talking about lmao?

Maybe if Pontiac spent more money on their engine development team, as opposed to scheming their way to more sales... by taking the names of famous races for their models (LeMans, TransAm, GranPrix, Bonneville, need I go on) along with paying high bucks for Hollywood stars such as Burt Reynolds to do their work for them, things might have been a little different.

Chevy produced, and always produced, quite well. Sorry if this tends to bother you as a Pontiac fan...

snaggeltooth

11-24-2006, 02:55 PM

Outlaw it? What the devil are you talking about lmao

Ohh so I guess you never heard of the Banshee..When Pontiac came out with it GM said No ..The Corvette will be our fladship and the only two seater ... The car came out in 1966 with a 326 , so you know a 421 Tri Power would have fit right in...
I wonder how well Bandit would have done with a 77 350 Chevy ...

You also admit that GM let Chevy come out with a engine that was well above its posted 450 Hp .... I guess it ihas nothing to do with the fact it was a Chevy ....

9T8W66

11-24-2006, 03:44 PM

I'll put up any version of Chevy's 396 against any version of Pontiac's 400, any version of Chevy's 427 against any version of Pontiac's 428, and any version of Chevy's 454 against any version of Pontiac's 455. There you go. My argument was their cylinder head design, and NOT their yearly factory displacement. Go ahead. Pick an engine, and lets continue on with this ridiculous discussion... ;)

I'll Take that Bet
`69 CHEVELLE L89 VS `69 GTO R/A IV
M21's with 4.10's and 4.33's respectively

All things being Equal it would be a toss up

And you didn't say anything about 409's vs 421's ? I wonder why ?

Street Lethal

11-25-2006, 09:09 AM

Ohh so I guess you never heard of the Banshee. When Pontiac came out with it GM said No. The Corvette will be our fladship and the only two seater. The car came out in 1966 with a 326 , so you know a 421 Tri Power would have fit right in...

The "Banshee" concept was just that, a concept. This never had anything nothing to do with the Rat vs Poncho engines, which makes it completely irrelevant in this discussion. You were not there next to DeLorean at that particular time, so nobody knows the real truth as to it's cancellation...

I'd be the first to admit, much like Mickey Thompson's hemispherical cylinder heads, that the "Banshee" project would have been a great move for Pontiac. But it didn't happen, so let's get over it, shall we...?

I wonder how well Bandit would have done with a 77 350 Chevy...

With the right dynamic compression, duration and lift, I'm sure he would have done just fine. Incidently, I have a buddy who runs 12's with a naturally aspirated, anemic, but worked, 305 small block Chevy. You were saying again...?

You also admit that GM let Chevy come out with a engine that was well above its posted 450 Hp. I guess it ihas nothing to do with the fact it was a Chevy...

I'd be the first to admit that Chevy got away with murder, but this doesn't take anything away from their engine designs. The big block Chevy was a powerhouse, and although they made various versions of them, all of them share the same potential of mega horsepower and torque, because of those cylinder heads...

I'll Take that Bet, `69 CHEVELLE L89 VS `69 GTO R/A IV M21's with 4.10's and 4.33's respectively...

Was that a joke? Let's stick with dyno numbers please, as we're talking about engine horsepower and torque, as opposed to elapsed times. If I wanted something to demolish your '69 Ram Air IV in the quarter mile, I wouldn't bother with a big block, I'd simply go with a cheap and modded high winding 327 Chevy, in a 2500-lb car...

And you didn't say anything about 409's vs 421's ? I wonder why ?

Irrelevant. Much like the Chevy small block 400, the big Chevy 409, although having loads of potential, is something I wouldn't bother with, stock (which is why I didn't bother mentioning it). Does this make the factory 421 Pontiac better than the factory 409 Chevy? Maybe. Does the Chevy 409 have more long term potential than the Pontiac 421? Most definitely...

Again though, we go round and round like we're in a square dance, dodging the original argument. LS6 vs SD-455. LS6 wins. Just admit it already, will ya... ;)

snaggeltooth

11-25-2006, 09:47 AM

I love the way that if you take a SB chevy and do this and that to it it can become as strong as a Poncho...That is aslong as the Poncho just sits there and gets nothing done to it .....lol... Nice advantage for Chevy ....

snaggeltooth

11-25-2006, 09:52 AM

Again though, we go round and round like we're in a square dance, dodging the original argument. LS6 vs SD-455. LS6 wins. Just admit it already, will ya...

Muscarcar Magazine had a shootout of all the top stars of the Muscle cars .. Hemis , Ls6 , 428cj. 455 stage 1s and W-30 $55.. And there was a guy with a RAM AIr II Firebird that was cleaning all their clocks .. just goes to show mega HP dont always win races .. Say what you will...
and it was a stock class only thing changed was you could run modern tires but had to be age specs ....

9T8W66

11-25-2006, 11:43 AM

Dyno numbers don't mean Squat.
Dyno's are tools for tuning Nothing more.
The real test is Quarter mile. because the car with the most Power doesn't always win.
We are talking stock for stock aren't we ?
If we are then my original statement still stands L89 Vs Ram Air IV
You said any version vs any version.

And LS6 vs SD 455 is closer than you think
The LS6 with the right Trans and gearing is obviously Quicker (M21 4.11)
But the most gearing available for and SD was 3.42 (auto or 4spd)
A 3.31 geared Automatic LS6 is not going to Destroy an SD 455
Add to that, That the SD will run on Pump Gas with a Quad an iron intake and a Hydraulic cam vs the LS6's Holley, Aluminum High Rise, Solid Lifters, and 110 Octane.

It's Obvious we all love these Cars Our passion for them is undeniable.
Peace

05gtoautoX

11-25-2006, 10:11 PM

arguing with this guy(street lethal) is a waste of time, he's a hard core chevy guy, He's going to defend the SBC/BBC till the end, just as some of us would the poncho. He obviously hasn't run into many ponchos is his BBC powered car, Otherwise he may have a different opinion. And one more thing, he wants us pontiac guys to prove him wrong, and give him a reason why the poncho engine is as good or superior to the LS-6. Well from what I've read all he can say is the heads on a BBC are bigger, I've stated my thoughts on this,
Using his theory no car in stock configuration in the the same decade (1964-1974) could come close to outrunning any chevrolet vehicle in stock configuration. Does that sound right? well, don't bother responding to this streetlethal, I won't be back on this thread. As i said, I'm a poncho guy you're a chevy guy, we'll never change, or will our thoughts. So :cheers: Maybe I'll see you at the track.

Street Lethal

11-26-2006, 05:58 AM

Guys, are you even reading any of my posts lol. Yes, I happen to be a Chevy guy, who currently owns TWO Pontiac Firebirds, a '92 Firebird, and a '98 Trans Am... :rolleyes:

Now, the argument was Rat vs Poncho, and which engine has more potential, horsepower and torque wise. From the factory, the LS6 was more powerful than the SD-455. None of you bother to admit this fact, you just blow smoke by continually spewing meaningless things, while emphatically countering the real discussion here with "if Pontiac did this, and if Pontiac did that"... but guess what, they didn't.

Dyno numbers don't mean Squat. Dyno's are tools for tuning Nothing more. The real test is Quarter mile. because the car with the most Power doesn't always win...

Having a Grand National powered '92 Firebird, in which finally presented me with a ten second time slip just before e-Town ended it's season last weekend, I more than agree with that statement of yours. However, if anyone cared to actually read my posts though they'd find that I'm not referring to track results...

You Pontiac guys are a little too superficial, don't you think... ;)

snaggeltooth

11-26-2006, 07:49 AM

Nope Im not going to admit a LS6 is more powerful than a 455Sd ... Nope because you are running a 11to 1 engine vs a 8.4 to 1 engine ... Make the engines equal and then we will see ...

Street Lethal

11-26-2006, 09:11 AM

Nope because you are running a 11to 1 engine vs a 8.4 to 1 engine...

I am? I'll give you two very specific engines, during two very specific years, with two completely different compression ratio's, in Pontiac's favor. How does that sound....?

1970 Pontiac 455-CI, 4 Barrel, Bore and Stroke of 4.1510×4.21, 10.25 Compression Ratio, Maximum Brake Horsepower 370 @ 4600-RPM, Maximum Torque Lbs. Ft. 500 @ 3100-RPM...

1971 Chevy 454-CI, 4 Barrel, Bore and Stroke of 4.251×4.00, Compression Ratio 9.0, Maximum Brake Horsepower 425 @ 5600-RPM, Maximum Torque Lbs. Ft. 475 @ 4000-RPM...

Please note that I used a '71 Chevy engine because you wanted an engine that shared a similar compression level. The 454's used during the '70 production year ran over 11.00 compression. The '71 454 version I used above only squeezes 9.0, and yet it still makes more power than the 10.25 Pontiac 455...

Where's your factual proof...? :)

snaggeltooth

11-26-2006, 09:44 AM

in 1970 a 455 was not offered in a firebird or GTO so you have a regular big car motor..
I do not know what engine you have there the LS5 in 1971 only put out 365Hp... Must be another one of those special chevy Motors GM let them put out ..
Ohh thats right it is the ZR2 a Vette only engine ....

snaggeltooth

11-26-2006, 12:17 PM

Another Corvette Legend: The 1971 LS6
The LS6 engine RPO has been offered once before in Corvette history, but only for one model year (1971). With 454 cubic inches (7.4 liters), a cast-iron "big-block" and aluminum heads, the first LS6 was second only to the full-blown L88 racing engine offered from 1967 through 1969 - in terms of both power and legend.

The original LS6 produced 425 bhp (gross) and was the most powerful engine offered in 1971. Only 188 cars were produced with this powerplant, less than one-percent of Corvette's 21,801-production run for the year. The option price was $1,221.00, or 22-percent of the coupe's $5,496.00 base price.

When tested by a leading automotive magazine, an LS6 with a four-speed manual and a 3.36:1 limited-slip differential produced the following numbers:

• 0 to 60 mph = 5.3 seconds
• Quarter-mile = 13.8 seconds@105 mph
• Fuel economy = 9-14 mpg

Also in 1971 a ZR2 package was offered. It was priced at $1,747.00 and included the LS6, a heavy-duty, close-ratio four-speed manual transmission, heavy-duty power brakes, transistorized ignition, lightweight aluminum radiator, special springs, shocks, and front and rear stabilizer bars. A total of only 12 ZR2-equipped Corvettes were produced, making them even rarer than the Z06 models referenced earlier
Funny you didnt mention that .....

9T8W66

11-26-2006, 03:57 PM

I am? I'll give you two very specific engines, during two very specific years, with two completely different compression ratio's, in Pontiac's favor. How does that sound....?

1970 Pontiac 455-CI, 4 Barrel, Bore and Stroke of 4.1510×4.21, 10.25 Compression Ratio, Maximum Brake Horsepower 370 @ 4600-RPM, Maximum Torque Lbs. Ft. 500 @ 3100-RPM...

1971 Chevy 454-CI, 4 Barrel, Bore and Stroke of 4.251×4.00, Compression Ratio 9.0, Maximum Brake Horsepower 425 @ 5600-RPM, Maximum Torque Lbs. Ft. 475 @ 4000-RPM...

Please note that I used a '71 Chevy engine because you wanted an engine that shared a similar compression level. The 454's used during the '70 production year ran over 11.00 compression. The '71 454 version I used above only squeezes 9.0, and yet it still makes more power than the 10.25 Pontiac 455...

Where's your factual proof...? :)

Gimme a Break
The 1970 455 was less power full even than the 428 HO from `69
It uses the same cam as the 350 HP 400's. the 067 (P) Grind 273/289 410/410
I'd rather have a `71 (LS5)455HO at least it has an 068 (S) cam and Round port Heads.

Street Lethal

11-26-2006, 04:09 PM

in 1970 a 455 was not offered in a firebird or GTO so you have a regular big car motor. I do not know what engine you have there the LS5 in 1971 only put out 365Hp... Must be another one of those special chevy Motors GM let them put out...

Again, you jump to an entirely different argument. You asked me to make the engines equal (in reference to compression levels), and then we will see. Well, I offered a 454 with only 9.0 compression (in comparison with the Pontiac's 10.25), yet it still made much more horsepower. These engines were offered from the factory, so what's the problem?

You keep jumping to the "special" Chevy's that were made, which is completely irrelevant to this argument. These engines were both offered from the factory, with Pontiac clearly having the compression advantage (as per your request), and the Chevy made more power, with much less compression. I did not use the Super Duty engines because of their low compression levels, you wanted something higher, and your still not happy... :rolleyes:

What would be a more fair comparison on your behalf? Would you prefer the Pontiac's engine to have some unbelievable cam spec's such as 795/800 995/1000 @ 100-LSA, with the Chevy having 115/120 350/365 @ 125-LSA? Would this make it more fair then lol....? ;)

Street Lethal

11-26-2006, 04:16 PM

It uses the same cam as the 350 HP 400's. the 067 (P) Grind 273/289 410/410. I'd rather have a `71 (LS5)455HO at least it has an 068 (S) cam and Round port Heads....

AND THERE WE HAVE IT!!!!! BINGO!!!! GET THIS MAN A CIGAR ROTFFLMMFAO!!!!

That was exactly my point this whole freaking time, and wow, it only took a few pages to get it across for you Pontiac fans. Bigger heads, means taking advantage of more dynamic and static compression levels, as well as duration and lift. Period. That is where the power is found, the cylinder heads, and since the Rat heads are bigger, they'll always be able to flow and handle more (in reference to compression, and cam specs). Is this so freaking hard to comprende lol....?

snaggeltooth

11-26-2006, 04:31 PM

Again, you jump to an entirely different argument. You asked me to make the engines equal (in reference to compression levels), and then we will see. Well, I offered a 454 with only 9.0 compression (in comparison with the Pontiac's 10.25), yet it still made much more horsepower. These engines were offered from the factory, so what's the problem?

Are you kidding me a Race engine out of a Vette vs a engine out of a Catalina or Bonneville .... Didnt read the article it was the LS6 in the 71 Vette ...and all of 12 were made .. Why not put a LS5 vs a 455 ho ... but playing by the rules has never been a stong point for chevy anyway .. I though GM put a ban on all factory backed raceing ...must have a big BACK DOOR over there at GM seems a lot of things went through it ...

Street Lethal

11-26-2006, 04:42 PM

Snaggle, I'm going to try simplifying my argument by using two Chevy engines. Since I'll be avoiding the Pontiac's, maybe then you can avoid being so darn one-sided... ;)

There have been plenty of articles comparing the 454 Chevy Big Block, to the 454 (Motown inspired) Chevy Small Block. With all things being equal, the engines produced similar numbers on the dyno (as expected), but when it came time to bigger valves, hogging out the heads, and bumping up compression levels, the small block (smaller block, literally) was now very very limited (in comparison to the Big Block)...

The bigger the block, the more bore and stroke that can be utilized. The bigger the heads, the more flow, duration and lift that can be taken advatnge of. It's not rocket science, you know... ;)

snaggeltooth

11-26-2006, 05:00 PM

9T8W66

11-26-2006, 05:16 PM

Airflow isn't everything, High velocity is what fills the chamber efficiently
And Pontiac designed their heads for maximum power in the normal operating range. The standard D port head didn't change much between `67-`79 they were designed to flow the most amount of air at low to mid valve lift up to .400
Cam timing was set up for Broad flat torque curves.
Here are some standard Pontiac grinds
067 273/289 410/410 350HP 400's, 360HP 428's, and `70-`76 standard 455's
068 288/302 413/413 389 3x2's, 360HP automatic 400's, automatic R/A III's, 390HP 428HO, all `71-72 455HO's
744 301/313 413/413 R/A 389 3x2, manual trans R/A 400's
041 308/320 469/469 400R/A II, 400 R/A IV Preproduction SD455, (changed to 744 grind to meet EPA mandate).
The last Pontiac to use Solid lifters was the `62-63 421 SD
As you can see the 041 Ram Air IV grind is the only cam with over 410 valve lift. This was to take advantage of the better flowing round port heads.
Do some real research on the SD455 Heads and you may discover that they are THE Best Flowing Factory Pontiac Heads available on a Regular Production Engine. The Heads were codesigned by a little known company back then named Air Flow Research.

This argument is getting old already but at least it's Entertaining:ughlaugh:

Street Lethal

11-26-2006, 05:23 PM

The thread started out that somewhere a SD 455 beat or could beat a LS6 Chevelle ... that is not engine for engine that is car for car ... And not you or anyone else is going to convince me one cant ...

Despite what the thread "started" out with, I initially stated my opinion that, for what it was worth, I'd go with the 454... because of the advantage that it had with it's cylinder heads. Where it went from there, who the heck knows.

As for the actual, factory race itself, that would simply be a theoretical question, as drivers, and TIRES come into play (neither car will hook from the factory stock), but if they did, the LS6, with it's more dominant engine (if it hooks), will take the Super Duty in the quarter mile (the eighth mile I would give to the Poncho), stock for stock, in my opinion...

Weight isn't too much of a concern, especially when you consider every hundred pounds costing a tenth in the quarter mile. The LS6 will still edge it out in the quarter (if it hooks, and w/the right driver). I'm not trying to pursuade you, I'm simply stating my opinion (in reference to racing), but if we're talking dyno numbers though, which I was for the last couple of pages, the Rat wins...

Street Lethal

11-26-2006, 05:38 PM

Airflow isn't everything...

Superior airflow is what separates the LSX engines from the Small Block Chevy. That's not to say that the aftermarket doesn't have the Small Block Chevy covered, but we were talking stock engines here, right....? ;)

High velocity is what fills the chamber efficiently. And Pontiac designed their heads for maximum power in the normal operating range...

I already explained my argument regarding the 454-SBC vs 454-BBC. Yes, the Pontiac can make just as much, if not more, than the Chevy 454.... with all things being equal, however, there's way too much advantage on the side of the Rat engine.

... and yes, high velocity is what fills the combustion chambers efficiently, but when your talking about 572 cubic inches in displacement, which Chevy offers, the bigger heads (in size) will easily handle it's needs, and then some.

Yes, this argument is getting pretty old, and it's been debated for quite some time by many others. However, I only keep responding because of the responses I get. Twisting what I'm saying, when in fact, all I'm saying, is that the BBC cylinder heads have the advantage, when it comes to making more horsepower. I see street legal 4 cylinders, albeit blown street legal 4 cylinders, running sub ten second passes, so I'm not impressed when I see a '74 455 inspired Trans Am running in the elevens... :rolleyes:

I'm not talking about racing, never was.

snaggeltooth

11-26-2006, 05:41 PM

http://i76.photobucket.com/albums/j16/snaggeltooth/newresume002Large.jpg Let me tell you what line 6-7 say.....
1974 SD 455 Trans Am 13.12/105.46
1970 Chevelle ls6 13.15/105.09
cars must have original body,and full factory Interior.Engines must be same engine family and displacement as was available in the make / model / year.Heads must be original as available on engine.all engine components are limited to original-type factory equipment. DOT street tires , limited to 9 inch footprint with a cold durometer of 50 are required ...as was recorded in NMCA's Flowmaster Challenge

Street Lethal

11-26-2006, 05:48 PM

^You think that proves your argument? Why do you think I brought up the F.A.S.T class a few pages ago (the article entitled, Finally the Proof)...? You must be one of those Car & Driver guys who think those tests are factual, when, as I already stated, it comes down to drivers, as well as hooking the tires, in which if you don't, will cost your dearly. I thought every racer knew this...lol?

Street Lethal

11-26-2006, 05:58 PM

In case you missed it;

I see street legal 4 cylinders, albeit blown street legal 4 cylinders, running sub ten second passes, so I'm not impressed when I see a '74 455 inspired Trans Am running in the elevens... :rolleyes:

I'm not talking about racing, never was.

snaggeltooth

11-26-2006, 05:59 PM

No these are just normal guys who go out and race their cars ...All I have said is that a LS6 could be beat by Sd 455 .. and there is one that did it came out of Musclecar review Magazine ... Just like it might have happened at any dragway on any weekend

Street Lethal

11-26-2006, 06:06 PM

Well then, that we can agree on. Although '70 Pontiac Trans Am's rarely run here in Englishtown, due to their rarity, and now collectible status, when they do run, their running some unbelievable times. For me to state that Chevy dominates Pontiac at the track would be wrong, and something I didn't mean to imply, especially when there are four cylinders out there that dominate us. I was talking dyno-power... ;)

snaggeltooth

11-26-2006, 06:38 PM

Well crap ...we cant start agreeing .. I have liked talking on this ... I must say you have been very good about not useing any personal attacks or anything like that .... So I guess you get a Well Done ...

Street Lethal

11-26-2006, 06:46 PM

Ditto. If you ever decide to come out my way for some friendly heads up racing, I'll be pretty easy to find, as I literally live at the track (something the wife isn't too fond about lol). First round's on me... :beer:

snaggeltooth

11-26-2006, 06:49 PM

Thanks for the invite , but thats a pretty good hop...;o;..

snaggeltooth

11-27-2006, 09:03 AM

http://www.dazed-and-confused.net/cars.htmlhere is a link that breaks down all the cars...

Gleomyr

11-27-2006, 09:44 AM

wow and thats that huh? I have really enjoyed reading this forum for the past several days now. I can honestly say I have learned a lot from it... I love my Firebirds and always will, I almost have my dream car at age 20 ^^. I want to take my 1970 Firebird Esprit and turn it into an as original as possible 1973 Trans Am SD-455, Brewster Green to show and maybe race now and again.

I joined this site just to participate in this forum, I am really glad I did there is a wealth of information (sometimes biased but thats ok ^^) here and everyone seems pretty friendly even when there are fairly large disagreements.

Someday when I get my car all done I will have to post some pictures and some times... I have never been to a track yet (to watch or otherwise) I know the people who own Quaker City Raceway here in Salem Ohio though so I am hoping to change that soon.

snaggeltooth

11-27-2006, 10:14 AM

You have a T/A hood ?? if you dont let me know ...I have a complet hood and shaker set up..

9T8W66

11-27-2006, 10:28 AM

It is fun to banter back and forth about stuff that really doesn't matter.
This just shows How much passion we have for Our Hobby

Guys It has been a Pleasure:cheers:

Gleomyr
If you need any info just throw me a PM some time I'd be Glad to Help if I could.

Jims455

11-27-2006, 06:30 PM

Originally Posted by Street Lethal
I see street legal 4 cylinders, albeit blown street legal 4 cylinders, running sub ten second passes, so I'm not impressed when I see a '74 455 inspired Trans Am running in the elevens...

what impresses me the most is how little money it takes to make the 455 run tens and how much money the four cylinder takes. Add to that the fact that the four is gonna blow-up in the short-short while the BB will run and run and run.
more power to the classic iron, use the fours for boat anchors

iLIKEtransAMS

11-28-2006, 01:13 PM

use the fours for boat anchors[/QUOTE]

hell yeah:nana:

Street Lethal

12-01-2006, 08:20 PM

what impresses me the most is how little money it takes to make the 455 run tens and how much money the four cylinder takes. Add to that the fact that the four is gonna blow-up in the short-short while the BB will run and run and run...

No doubt. It takes very little money in getting the 455 to run in the tens. However, you have to give credit where credit is due sometimes (in reference to those little four bangers). Also, try not to forget, there's no such thing as a Pontiac Big Block, Jim... ;) ;)