Dazed and Confused SD 455

**Street Lethal** · 11-26-2006, 03:42 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, 04:00 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 ...

**9T8W66** · 11-26-2006, 04:16 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

**Street Lethal** · 11-26-2006, 04:23 PM

Originally Posted by snaggeltooth

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, 04:38 PM

Originally Posted by 9T8W66

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....?

Originally Posted by 9T8W66

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...

I'm not talking about racing, never was.

**snaggeltooth** · 11-26-2006, 04:41 PM

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, 04:48 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, 04:58 PM

In case you missed it;

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...

I'm not talking about racing, never was.

**snaggeltooth** · 11-26-2006, 04:59 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, 05:06 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, 05:38 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, 05:46 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...

**snaggeltooth** · 11-26-2006, 05:49 PM

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

**snaggeltooth** · 11-27-2006, 08:03 AM

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

**Gleomyr** · 11-27-2006, 08:44 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, 09:14 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, 09:28 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

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, 05:30 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, 12:13 PM

use the fours for boat anchors[/QUOTE]

hell yeah

**Street Lethal** · 12-01-2006, 07:20 PM

Originally Posted by Jims455

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...