[ponyakr]

"...Porting, polishing, welding,
epoxying, and acid-porting permitted. Grinding and polishing in
combustion chamber permitted..."


Well, if I understand the English language, that means any type of hand or machine porting is OK.

To me, that means that the CNC porting that some Pontiac shops do is SS legal. Also, I suppose that most any hand porting that increases flow is legal.

Is that the way ya'll interpret the rule ?

So, I think I've read of lots of guys/shops that can port iron heads to flow at least 240cfm or more.

To me, that means that low buck Pontiac SS engine builds can use home or shop ported heads, which will provide enuff flow to make needed power to run the index.

Just curious. For you guys who hand port iron heads. What would you charge for porting some iron heads for a SS build ?

Let me also ask this question. For those who don't port their own heads, but have paid to have a set ported, recently, what did the porting cost ? Were they flowed ? If so, what was the cfm ?

We know the retail price STARTS @ around $2000, for complete porting & valve job.

http://www.sdperformance.com/viewPro...?productID=583

https://butlerperformance.com/i-2445...tegory:1234782

But, I don't know how long a guy would have to wait, for Butler or SD to get around to their stuff.

So, who can do this work, AND actually do it within a reasonable amount of time ? Paul K ? Who else ? Time to name names, if you know any.

http://www.nitemareperformance.com/cylinderheads.html

https://www.hotrod.com/articles/hrdp...pontiac-heads/

[Stan Weiss]

Originally Posted by ponyakr

Got a pdf copy of the 2014 NHRA rule book.

Here's what it says about driver weight.

"...Class is determined without
driver weight. Once classification weight is calculated, 170 pounds
will be added for driver to arrive at minimum weight..."

Here's the head rule.

"...CYLINDER HEADS
Must be correct casting number for year and horsepower
claimed, per NHRA Technical Bulletins or NHRA-accepted.
Cylinder-head casting must also be on NHRA runner volume list
as published on NHRARacer.com. Porting, polishing, welding,
epoxying, and acid-porting permitted. Grinding and polishing in
combustion chamber permitted. Welding and/or applying epoxy
in combustion chamber prohibited. Spark-plug hole must
maintain the stock location, size, and angle as machined by the
OEM; spark-plug adapters prohibited.Valve-guide centerlines
must maintain the stock lateral and front-to-back location as
machined by the OEM.Valves must maintain stock angle; valvestem angle must remain stock, +/- 1 degree. Cylinder head must
be able to hold combustion chamber, intake and exhaust runner
volumes per NHRA Specifications. Any aftermarket steel valve
permitted; must maintain stock head and stem size; titanium
valves prohibited. (OEM sodium-filled valve may be replaced with
titanium, provided weight is equal to or greater than original.)
Valve diameter permitted to be +.005-inch or -.015-inch from
published NHRA Technical Bulletins. External modifications
prohibited, intake side of head may not be cut into any part of
valve-cover bolt holes (except for SS/AH).Valve-cover bolt holes
must remain unaltered and in their original location. Welding or
epoxying permitted on external portion of runners for repair only,
maximum 2 runners per head. Heat riser passages may be
blocked off from intake-manifold side of cylinder head or in
exhaust port. The following are permitted: polylocks, jam nuts,
screw-in or pinned studs. Any valve job accepted. Exhaust plate
permitted between header and cylinder head, maximum 1/2-inch;
may not protrude into exhaust port. Cylinder head may have all
seats replaced..."

Originally Posted by ponyakr

"...Porting, polishing, welding,
epoxying, and acid-porting permitted. Grinding and polishing in
combustion chamber permitted..."


Well, if I understand the English language, that means any type of hand or machine porting is OK.

To me, that means that the CNC porting that some Pontiac shops do is SS legal. Also, I suppose that most any hand porting that increases flow is legal.

Is that the way ya'll interpret the rule ?

So, I think I've read of lots of guys/shops that can port iron heads to flow at least 240cfm or more.

To me, that means that low buck Pontiac SS engine builds can use home or shop ported heads, which will provide enuff flow to make needed power to run the index.

Just curious. For you guys who hand port iron heads. What would you charge for porting some iron heads for a SS build ?

Let me also ask this question. For those who don't port their own heads, but have paid to have a set ported, recently, what did the porting cost ? Were they flowed ? If so, what was the cfm ?

We know the retail price STARTS @ around $2000, for complete porting & valve job.

http://www.sdperformance.com/viewPro...?productID=583

https://butlerperformance.com/i-2445...tegory:1234782

But, I don't know how long a guy would have to wait, for Butler or SD to get around to their stuff.

So, who can do this work, AND actually do it within a reasonable amount of time ? Paul K ? Who else ? Time to name names, if you know any.

http://www.nitemareperformance.com/cylinderheads.html

https://www.hotrod.com/articles/hrdp...pontiac-heads/

Based on what I highlighted in your first post most of those ported heads would be illegal and the few that were not illegal would be down on the needed flow. There is a good reason that SS heads cost so much money. We can start with all of the furnace brazing that must be done to an Iron head before it is then ported.

Stan

[ponyakr]

So, according to what you're saying, even a common gasket match would be illegal for SS, because it would increase the size/volume of the ports ?

So whatever volume of material is removed, that same volume must be replaced by epoxy, or some other material ?

For the time being, I'll have to remain skeptical that NHRA techs would DQ a SS car, because of a MILD street porting job.

One reason I say that is because they pass all the Stocker heads that have had all sorts of acid porting. Those ports have to be a lot bigger than factory. Don't make sense that they'd allow such big ports for Stock, then be so strict on SS heads.

[Stan Weiss]

Originally Posted by ponyakr

So, according to what you're saying, even a common gasket match would be illegal for SS, because it would increase the size/volume of the ports ?

So whatever volume of material is removed, that same volume must be replaced by epoxy, or some other material ?

All I am doing is pointing out what one line in the rule book says. There are other lines in that section which some people interpret differently. Like how much can or can not be milled off of the intake size of the head to help reduce intake runner cc's

Stan

[ponyakr]

Originally Posted by Stan Weiss

...how much can or can not be milled off of the intake size of the head to help reduce intake runner cc's

Stan

Yeah, I had finally figured that one out. The more you cut off the intake side, the more material you can remove from the ports, without having too much volume.

So, Stan, I've come to a conclusion here. I figure it must be one of 3 ways.

Either:

(1) You're the ONLY guy here who knows anything about this.

(2) OR, others who know, either haven't read it, or CHOOSE not to respond.

(3) Anyhow, you are the only one, at this point, who seems interested enuff to discuss it, rather than just saying it costs up to $10k to have a set done correctly.

Since I personally don't think all the low buck SS racers are paying that much for head work, just to run barely under the index, I'm gonna keep drillin on this, 'til I'm satisfied about it.

To clarify, I understand that not many SS cars are "low buck". I'm speakin comparatively. Like, as compared to the deep pocket guys who can pay $100g and more for a new FS car.

So, Stan, (and anybody else who has experience porting iron Pontiac heads), I'd like to now continue with my questions about legally porting Pontiac heads for the SS class.

OK, it is said that you can do most anyhing inside the ports, as long as it does not produce a bigger volume port than what NHRA says is legal for a given head.

So, to make this easy, lets use the very popular & common 6x head. I suppose that because so many of these have been used on 455+ strokers, it may be the most ported of all Pontiac heads.

AND, there are plenty of these heads out there that guys can measure.

So, lets look at the port volumes NHRA allows for the 6X head.

OK, for the '77 350 heads the Intake volume is said to be 161cc Exhaust volume 148cc

http://www.classracerinfo.com/Engine...3&MAKE=Pontiac

Same volumes given for the 6X heads legal for the '77 180hp 400.

http://www.classracerinfo.com/Engine...4&MAKE=Pontiac

So, if you run a 6X head engine, the port volumes can't be any bigger than 161cc & 148cc.

So, what I wanna know is: What are the actual port volumes of as produced, unported, virgin 6X heads ?

I know lots of guys have reported that the actual chamber size of some virgin heads are lager than advertised, sometimes quite a bit larger.

I assume that as with blocks, there can be some core shift, which would alter the volume of some ports.

BUT, on average, what are the intake & port volumes of unmolested 6X heads ?

I suppose that thru the years, Stock racers have used all forms of rust & corrosion methods to enlarge ports.

Anyhow, if any port is smaller than the NHRA spec, then material can be removed from that port, without making the head illegal.

For you guys who have measured port volumes of virgin 6X heads, what kind of numbers did you come up with ?

After lookin at quite a few factory iron heads, it's my observation that SOME heads have one or more ports that are quite out of shape. You can put a stock intake gasket or exhaust gasket up against the ports, & easily see that the mouth of some ports are smaller than the hole on the gasket. That's what "gasket matching" is all about, making the port the same size as the gasket.

BUT, I assume that if even this tiny bit of material removal, will make the port volume too big, then the head is illegal for SS, unless & until you add some type of material to the inside of the port, to decrease volume.

I think this is the correct interpretation of the NHRA rules.

So, before I can proceed with this any further, I need for guys with 6X heads, which are off the engine, to help us, by measuring your intake & exhaust ports.

And, this in NOT just for unmolested heads. I'd like some numbers form heads that have had only a minor gasket match, and some that have had a minor port job, up to maybe 220-240cfm intake flow, AND some that have had a serious port job, up to maybe 250cfm or more.

I've never measured the volume of a port. But I assume its done the same way as measuring the volume of a chamber. Also assume that a valve would have to be sealing off the port, otherwise, the checking fluid would just run out the hole where the valve was suppose to be. If not, somebody please explain the procedure & describe the equipment/tools needed.

THANKS for any & all help in gathering this port volume info !

[ponyakr]

Since all this about port volume has come up, I decided to look up a few NHRA port volume specs, for Pontiac heads.

Some very interesting numbers have turned up.

For a 1968 375hp 428 engine, the only factory head listed is a #216. Didn't think it was anything special. But look at the listed port volumes. Intake = 188cc, Exhaust = 182cc.

https://www.jegs.com/i/Edelbrock/350/60587/10002/-1

Those numbers sound bogus to me. Don't think those heads are anything special. Just common D-ports. So, are those the ACTUAL allowable port sizes for the 216 heads ???

One reason I have trouble with this is because the '69 370hp 428 shows #16 heads, with only 165/152 port volumes. So, did the #216 heads actually have ports that were that much bigger than the ports in the #16 heads ?

http://www.classracerinfo.com/Engine...8&MAKE=Pontiac

Also, the alum Edelbrock 60587 heads are legal for SS. They show an intake port volume of 215cc. So, does NHRA allow those heads to be run with a 215cc intake port ? OR, must a guy add material to reduce the port volume. Just assumed the extra 10hp was added because the alum heads will flow more, thus makin more power.

https://www.jegs.com/i/Edelbrock/350/60587/10002/-1

So, anybody here know exactly what size intake ports are legal for theses heads, on a '68 428 engine ?

[Stan Weiss]

Note these are from Nov 2018. Attached is a list of NHRA cc's for heads. Also the Edelbrock head cc's must be the same as the Iron head that they replaced.

I don't have a link, but you should see if you can find the NHRAAcceptedProducts.pdf

Stan

PS - OK Found what maybe the latest list - http://www.nhraracer.com/Files/Tech/...edProducts.pdf

[Norman W]

Someone BS'ed NHRA on the runners of the 216 head. It was posted has been established by NHRA. Carroll Warling is running this head on his 428.

[ponyakr]

Originally Posted by Norman W

Someone BS'ed NHRA on the runners of the 216 head. It was posted has been established by NHRA. Carroll Warling is running this head on his 428.

WOW ! THANKS Norman !

[ponyakr]

Originally Posted by Stan Weiss

Note these are from Nov 2018. Attached is a list of NHRA cc's for heads. Also the Edelbrock head cc's must be the same as the Iron head that they replaced.

I don't have a link, but you should see if you can find the NHRAAcceptedProducts.pdf

Stan

PS - OK Found what maybe the latest list - http://www.nhraracer.com/Files/Tech/...edProducts.pdf

Thanks ! That puts 'em all in one list.

BUT, now I need to know the port volumes of virgin 6X heads, so that I'll know if the 6X heads can stand some MILD porting, or at least a gasket match, without makin the ports too big.

Would REALLY help if some guys can measure the port volumes in heads with various stages of gasket matching, up to full porting, so that I can get a ruff idea of how much material can be removed, before makin 'em illegal for SS.

Again, just assuming that there are more of these heads out there than any other Pontiac heads. And I know that LOTS of engines have been built with these heads, in unported, gasket matched, & various stages of porting. SO, that SHOULD mean there are more of these heads out there that could be checked, than any other Pontiac head.

ASSUMING that when a shop ports heads, they only report the flow, & don't report the before & after port volumes. Is this correct ? If not, somebody please post some flow sheets for 6X heads, that will give me the info I'm lookin for. Thanks !

This flow testing page on the Wallace site, shows that one of the intake ports on the 6X head they tested, measured 154cc. That's pretty close to the 153cc number I found somewhere else. So, maybe that's real close to the actual port volume of an unmolested 6X head intake port.

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

[Stan Weiss]

I think what you need to do is talk with a head porter. I would think if you don't want to do any welding that a port match would be the last thing you would want to do. I am saying that because I believe that are other areas in the head where some metal removal will yield much better results per cc of metal removed that a port match will.

Stan

These are some old dated quotes that I have found.

The intake ports of our 250-cfm heads measure around 165 ccs

SD

NHRASuperStock455SD

An average motor will go 6200 peak HP and 4700 peak torque with a cam about 106 L/S. Probably about 282/282 @ 0.050. This would be with 1.65 studded rocker systems like Crane, and average valve train....lets say 280 lbs on the seat and about 700-800 open, Proflow valves, and about .700 lift at the valve. Heads will flow about 250cfm.

A killer engine will have much better heads and flow about 285 with good flow and not bad flow. The ports will have good CSA minimum about 2.000 square inches. Small ports with high velocity flow do NOT WORK! (Too much cylinder head choke.) Our old heads flowed 240 cfm, but if they had good CSA they made very good power. Small heads with big flow are stones.

This bigger motor will have peak HP around 6700 and torque around 5200 larger tubed headers.

The better motor will also have valve spring upwards of 400lbs on the seat with 1100lbs open. Good rocker shaft system (T&D)

Use a ported Victor and dont even think about it. Bringing the flow dividers under the carb to promote equalization is way more important than trying to achieve shorter intake runners. We haver tried it both ways and and always lose power by making the runner shorter. The Victor manifold dropped peak HP and torque by 300RPM. At every point it was more power, but one can't help to wonder about gaining that 300RPM back. (A Victor with about 3 inches shorter runner and same CSA is what I think would be perfect).

The 400 motor with 16 heads is not as competitive as it has too much HP in SS compared to other combos. However, it will make very good power and is a very competitive SS engine.

Lynn

NHRASuperStock455SD

For calculating Super Stock NHRA combos it is a good idea to take the rated HP by NHRA and multiply times 2, and that would be the approximate engine dyno HP required to run a second under assuming you do all the drive train and chassis things very well.

400-6X motor
rated 285HP x 2 = 570HP dyno

428-16 heads
rated 320HP x 2 = 640HP dyno

455SD (if you have lots of money)
rated 325HP x 2 = 650HP

1974 4X 455
rated 310HP x 2 = 620HP

400-16 heads
rated 310HP x 2 = 620HP

400 RA-IV (lots of money)
rated 340HP x 2 = 680HP.

If we get the Edelbrock heads approved as a replacement for the round port heads, it will get moved around a little. NHRA will add at least 10HP to each combo when utilizing it. This means you need 20HP on the dyno additional to break even.

Lynn

[ponyakr]

"...For calculating Super Stock NHRA combos it is a good idea to take the rated HP by NHRA and multiply times 2, and that would be the approximate engine dyno HP required to run a second under assuming you do all the drive train and chassis things very well..."

I want to point out that the specs he mentioned, including those ridiculous .700 lift cams & super high spring pressures, are what's needed "to run a second under".

I don't really know how many ways I can say this.

YES, I realize that it takes a LOT of money & VERY extreme parts, in order to run a sec under.

I think that has been established well beyond any possible doubt.

BUT, I am trying to establish exactly what it would take to build a Pontiac Super Stocker that will just barely run it's index. If the index is an 11-flat, then the car will run at least an 11 flat. Does everybody reading this understand what I'm saying ???

From some of the calculators I mentioned, it appears that only around 500hp, or slightly less is required to run 10.90's-11.00's.

I think there have been LOTS of builds here of both 400 & larger cube builds that have made that much power, with iron heads. And we're talkin about pump gas street engines, with streetable cams, many of which were Voodoo.

For this build, we can use race gas & run any cam we want. Can also run a Victor, or any other single carb intake that will fit under the hood. As mentioned, the car can run a small converter with any stall speed needed, as well as a trans brake, & lightened TH350 or TH200 trans.

So, how about some of you guys who know a LOT about engine building try to help come up with a recipe that will make the needed 480-500hp, without fully ported heads, or a .600 & larger lift roller cam, with huge spring pressures.

I think this can be done. But I'm not an engine builder. My 455 Ventura bracket car ran 7.30's, on our 1/8 mile track. It was just a basic 455, with unported #215 heads, a Torker 2 intake, a 750 vac Holley, a decent HFT cam, that would idle below 1000 rpm. It couldn't have had much over 400hp/500 torque. Other than needing higher octane gas, it could have been very streetable.

Also, the 10" converter was what I call a tight 10". I could only hold the brake to 2000 rpm. So, I have to wonder how much quicker the car would have been, with a small loose converter, & a bigger HFT cam. I think just those 2 changes, if exactly the correct parts, the car could have run very close to 11-flat, in the 1/4. The car also had a long tail TH400, which didn't shift real crisp. It wasn't a light car either. It was a hatchback, with roll bars, ladder bars & frame connectors. The NHRA legal weight is right at 3500 lbs. And that is with a 350 engine/TH350 trans.

http://www.classracerinfo.com/Engine...px?ENGINE=2088

I think this can be done. So, do any of you guys have links to any engine builds that appear to show that, with the legal minor changes needed to make it SS legal, might make the needed 500hp ?

Something that might work would be a 9.5 CR unported iron head build, that made 450hp or more, with a streetable cam & Q-jet. If you took one of these engines, & swapped the cam out for a bigger HFT cam that would not be streetable, but would add 30-50hp, @ a higher rpm than the street cam used.

A lot of guys here are always talkin about not using a cam that will leave power on the table. Well, here's a chance for guys to recommend a HFT cam that won't leave any power on the table. Don't have to worry about idle or vac, just max power at the correct rpm for the engine.

I've read of the Stock guys trying lots of cams before finding the one that ran the best in their car. Since we're talkin about lower budget builds, I'd like to first consider only the big HFT cams, which can use Rhoads V-max lifters, & reasonable spring pressure.

If it turns out that a SFT or a roller cam is absolutely necessary, then so be it. But, even then, it needs to be something reasonable, that doesn't require the super high spring pressures.

[Stan Weiss]

I wish you luck. But ever time you pull something else off of the table it just get much harder and I just don't see it happening.

Stan

[ponyakr]

OK, maybe most here think this can not be done.

Here's an example of what I'm talkin about. at the link provided, look at the specs of the engine labeled: "...Pure-Stock Series 1968 Pontiac Firebird Ram Air 400..."

https://www.pontiacdiy.com/pontiac-v...-combinations/

"...Exhaust Exhaust Manifold: Reproduction round-port long-branch manifolds Exhaust Tube Diameter: 2.5-inch mandrel bent Muffler: Pypes Crossflow Exhaust Crossover: X-type Or Complete Exhaust Kit: Pypes Crossflow system Gearing Auto Trans Converter Stall Speed: 2,500 to 3,000 rpm Suggested Rear Axle Ratio: 4.33:1 Projected Output Measured Horsepower: 470 at 6,000 rpm Measured Torque: 490 ft-lbs at 4,000 rpm Additional Suggestions or Comments This engine is currently the fastest Pontiac combination at the Dan Jensen/Bob Boden Pure Stock Muscle Car drag race. Installed into Rick Mahoney’s 1968 Firebird that weighs 3,450 pounds with driver and has ran a quickest so far of 11.63 at 117.64 mph..."

The engine made 470hp @ 6000rpm. The cam was only slightly larger than an 041 Pontiac cam. "...Duration at .050 inch: 232/240, Lobe Separation: 112 degrees, Valve Lift at 1.5:1: .485/.485 inch

The car ran 11.63, with an iron intake, a 2500-3000 rpm converter, long branch manifolds with full exhaust system, & 4.33 gears. And as per F.A.S.T. rules, ran narrow hard street tires.

The heads were unported RA2, which flowed about 214cfm on the intakes.

So, take this engine, add a bigger, strip only HFT cam, a better(for racing) alum intake, open headers, 4.56 gears, a good racing converter that would stall at least 4000 or a little more, and some 9" slicks with CalTrac bars/springs, and it looks to me like the car would run high 10's, easily.

All-out Stockers with this engine have run low 10's for years.

So, ON PAPER, (the screen) it looks to me like you could run the SS index with a much less than all-out Stocker build.

Because of the cost, I wouldn't recommend using the RA2 round port heads for a lower cost build. So, I suppose D-port heads would reduce power slightly. But, D-port head 400 Stockers are also running mid to low 10's.

I think it could be done. If I had the money, I'd thrash it out 'til I found out exactly what it would take to just barely run the SS index, with different Pontiac combos.

I suppose most of the research would have to be done on a dyno. You'd need to try lots of cams, & heads in different mild stages of SS legal porting. I just don't think you'd need .700+ lift roller cams & huge spring pressures to run real high 10's. Hey, I could be wrong. If so, wouldn't be the 1st time.

The problem right now is that I haven't found many engine builds that don't have either alum heads or iron heads that have too much porting to pass SS tech.

[ponyakr]

I'm now lookin for more dyno results that might shed a little light in this deal.

Here's one I like.

This engine has a 4.25 stroker assembly. But, the 4.21 stroke of the 455 will not be that much different. Plus, SS rules allow a max of 4.229 stroke. So, the 4.25 stroke would be legal.

https://www.hotrod.com/articles/hppp...e-stuska-dyno/

I suppose the closest NHRA combination would be the '73-'74 D-port 455's. Those 4X heads would have slightly larger chambers, than those of the 6X heads, in the article. Max cubes 476.1, max CR 9.66:1.

http://www.classracerinfo.com/Engine...9&MAKE=Pontiac

Stan's info says the stock 4X heads will flow about 212cfm at .500 lift.

http://www.classracerinfo.com/Eheadf...YID=49&HEAD=4X

The cam used is said, by many here, to be much too small, even for a street Pontiac, much less a drag 455. It only has 224°/230° @ .050. Most say that a street 455 needs at least 230° @ .050 of intake duration, minimum. Many recommend something bigger.

Anyhow, the whole point of this post is to show that an iron head pump gas street 455 engine made 492hp, with a cam that was way too small. So, add a bigger strip only cam, even a HFT or SFT, and a Victor intake, and well over 500 hp should be possible. Cliff has posted that a Crower 60919 cam, with 1.65 rockers & Rhoads V-max lifters can make very similar power to small HR cams. So, a bigger HFT cam should be able to make more power than the puny little HR cam used in the build linked.

The ONLY possible choke point I see is the heads. I just don't know what the hp limit would be, with absolutely factory stock ports, and how much improvement could be made, with very minor, legal, grinding in the ports. Also don't know exactly how much ET difference the big torque of the longer stroke engine would make. Maybe by utilizing the big torque, you wouldn't really need that close to 500hp, to run high 10's. I suppose it would take lots of dyno & track testing to find out. Sure would be fun, at least to me it would.

So, can any of you guys post links to 455 builds using unported 4X, 5C, 6X, or similar heads ? How bout with some of these heads, with just minor home porting, or gasket matching ?

I know there have been LOTS of these engines built, over the years. But, I assume that most had small street cams, & were built for low rpm pump gas street duty.

[ponyakr]

Well, I've explained this deal as sorta like panning for gold, lookin for a nugget.

Well, here's the biggest nugget I've found, so far.

How about 529hp @ 5900rpm ? And this was over 20 years ago. I'm surprised this article is still on the net.

Never heard of the cam company mentioned. Assume it hasn't been in business for years.

Anyhow, this build used '71 model # 96 heads. Used a streetable SFT cam. Check out the numbers ya'll. Torque was 559 @ 4500rpm.

https://www.hotrod.com/articles/hrdp...ngine-buildup/

This engine had the heavy TRW pistons. It also used an old Torker 1 intake, which has been proven to be a bad choice for high power. I think some have posted that even a factory iron Q-jet intake will make more power. I assume there are dyno tests to prove it. Back in the old days, some of the Pontiac SS racers would take 2 Torker 1 intakes, cut 'em in the middle, then weld the 2 back halves together.

https://www.pontiacdiy.com/pontiac-v...ormance-guide/

https://www.hotrod.com/articles/hppp...d-carburetors/

http://www.sdperformance.com/newsStory.php?newsID=44

[Stan Weiss]

Originally Posted by ponyakr

Well, I've explained this deal as sorta like panning for gold, lookin for a nugget.

Well, here's the biggest nugget I've found, so far.

How about 529hp @ 5900rpm ? And this was over 20 years ago. I'm surprised this article is still on the net.

Never heard of the cam company mentioned. Assume it hasn't been in business for years.

Anyhow, this build used '71 model # 96 heads. Used a streetable SFT cam. Check out the numbers ya'll. Torque was 559 @ 4500rpm.

https://www.hotrod.com/articles/hrdp...ngine-buildup/

This engine had the heavy TRW pistons. It also used an old Torker 1 intake, which has been proven to be a bad choice for high power. I think some have posted that even a factory iron Q-jet intake will make more power. I assume there are dyno tests to prove it. Back in the old days, some of the Pontiac SS racers would take 2 Torker 1 intakes, cut 'em in the middle, then weld the 2 back halves together.

https://www.pontiacdiy.com/pontiac-v...ormance-guide/

https://www.hotrod.com/articles/hppp...d-carburetors/

http://www.sdperformance.com/newsStory.php?newsID=44

You are taking things and saying look at this but you need to look deeper

I would have to guess that those modified heads on that build are probable to big (cc's) to be SS legal.

Stan

[ponyakr]

Here's a Paul Carter pump gas, 6X head 455 that made over 500hp.

http://www.pontiaczone.com/forum/sho...75&postcount=1

http://www.pontiaczone.com/forum/sho...76&postcount=2

http://www.pontiaczone.com/forum/sho...3&postcount=54

[ponyakr]

"I would have to guess that those modified heads on that build are probable to big (cc's) to be SS legal..."


YES, I KNOW, I KNOW, I KNOW, I KNOW !!!!!

How many times do I have to say it. I KNOW that the heads are the choke point.

BUT, some of these engines are makin MORE than enuff power to run the SS index.

SO, who knows EXACTLY how much head flow is needed to make 480-500 hp in a Pontiac engine of aprox 470 cubic inches ? Anybody have links to any builds that might shed more light on this than those I've found so far.

Just to hear somebody say it can't be done is not good enuff for me.

I wanna know exactly how much power can be made without spending BIG bucks on super trick heads.

So, for now, I'll just keep panning. Thanks for any helpful info or links that might help find the info I'm lookin for !

[ponyakr]

Thinkin some more about the head choke deal.

Using a '68 428 should completely eliminate that choke point, if you can find some #216 heads.

The liberal NHRA legal port volumes should allow plenty of room for mild porting, without exceeding port volumes. Does anybody disagree with that ?

http://www.classracerinfo.com/Engine...9&MAKE=Pontiac

From what I've found, there are lots of Pontiac engine builders that can make big power with alum or ported iron heads. I just haven't found any builds where the goal was to make max hp with unported D-port iron heads. I assume the main purpose of such a build would be for building an engine which would be run in a drag class requiring unported D-port iron heads. Stock class racing, & some of the "Pure Stock" classes are the only such classes I can think of.