[ponyakr]

For all you head flow experts, & guys who know how to calculate power related to ET, here's a question.

I assume Randi Lyn Shipp's '67 Bird Stocker runs 670 heads.

The car has run quicker than 10.50, on several occasions.

So, although the NHRA Stock rules call for no porting, how much head flow is required for that car to run 10.50 ?

These old school Stocker combos that can run low 10's & high 9's & are quicker than the same combo was in SS form, back in the '70's, are very interesting to me. I know the unlimited valve spring pressure & cam duration play a big part. But, I don't think that MOST "as cast" factory heads will flow enuff to run the big numbers some are running today. Assume some form of "porting", which would have been illegal back in the old days.

Have read all sorts of methods that have been used to increase flow, such as acid porting, inducing rust, & even hand porting, and then covering it up, in various ways, so that it's hard to detect. Assuming that NHRA finally just gave up & decided to let it go. Have read that "Heads-Up" builds some of the very best flowing Stocker heads. There WAS a section on their site, vaguely describing their Stocker head port enlarging modification. But, that section disappeared, as of the last few times I tried to find it. The Stock section just says "Under Construction".

https://www.headsupcylinderheads.com...der-heads.html

[ta man]

Originally Posted by ponyakr

For all you head flow experts, & guys who know how to calculate power related to ET, here's a question.

I assume Randi Lyn Shipp's '67 Bird Stocker runs 670 heads.

The car has run quicker than 10.50, on several occasions.

So, although the NHRA Stock rules call for no porting, how much head flow is required for that car to run 10.50 ?

Every last cfm it can flow for as long as the valve can stay open and at a very high rpm.

[Formulajones]

Originally Posted by ta man

Every last cfm it can flow for as long as the valve can stay open and at a very high rpm.

Equals square lobe cams Keeping the lift per rules but duration is unlimited. Not great for longevity but doesn't matter in class racing where tear downs are part of the game.

[ponyakr]

Originally Posted by ta man

Every last cfm it can flow for as long as the valve can stay open and at a very high rpm.

LOL !

Yeah, it runs good.

But aprox how many cfm do you suppose the heads flow ?

Will a 400 Stocker engine make that much power @ 240cfm flow ? 250cfm ? 260cfm ? OR ???

[ponyakr]

"... on a stock 670 head I got it to flow 225 to 228 cfm..."

So, you think Randi Lyn's '67 Stocker can run 10.50 or quicker, with no more flow than that ?

OR, do you think the heads have been "massaged" to flow more ? IF so, how much more ?

I understand about Stocker "tricks" & "set-up" to run quick. BUT, the engine still has to make a certain amount of power to run the big numbers.

SO, since this thread is about 670 head flow, there's no better place to include the 670 heads on an NHRA Stocker.

Aprox how much would heads have to flow in order for a 400 Pontiac engine to turn 8000 rpm ? Is that something you guys can calculate ?

Bryan Phillips also has a 10 sec '67 Bird Stocker. So, I assume his 670 heads also flow more than a non-ported factory stock set.

[Stan Weiss]

Originally Posted by ponyakr

"... on a stock 670 head I got it to flow 225 to 228 cfm..."

So, you think Randi Lyn's '67 Stocker can run 10.50 or quicker, with no more flow than that ?

OR, do you think the heads have been "massaged" to flow more ? IF so, how much more ?

I understand about Stocker "tricks" & "set-up" to run quick. BUT, the engine still has to make a certain amount of power to run the big numbers.

SO, since this thread is about 670 head flow, there's no better place to include the 670 heads on an NHRA Stocker.

Aprox how much would heads have to flow in order for a 400 Pontiac engine to turn 8000 rpm ? Is that something you guys can calculate ?

Bryan Phillips also has a 10 sec '67 Bird Stocker. So, I assume his 670 heads also flow more than a non-ported factory stock set.

There is no set answer. The more the heads flow the less cam that is needed. The less the heads flow the more cam that is needed.

I will set the over under on HP @ 530 and take the under to run 10.50 with a DA of zero.

Stan

[ponyakr]

"...what flow numbers are possible from a 670 head with professional CNC porting? "

When I went back I read this, I decided to check on the SD CNC porting deal.

To my surprise, SD no longer fools with iron heads. I suppose I'm the last to know.

http://www.sdperformance.com/listPro...?categoryID=53

I suppose he has much more than he can do, with just alum heads.

So, who now has the best CNC program for iron Pontiac heads ?

Butler says they do more Pontiac heads than anybody else in the world.

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

I suppose there are several members here who do hand porting. I assume most members know who these guys are. Any who wish to advertise their porting services can. Don't know who now does a lot of CNC Pontiac iron head porting.

KRE shows lots of alum head CNC porting. But there is no mention, specifically, of porting iron heads.

http://www.krepower.com/Pontiac%20Cylinder%20Heads.htm

Nitemare shows Pontiac iron head porting services. Not a recommendation. Just a possible source.

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

Got this from a Google search.

https://headsandmanifolds.wordpress....-head-porting/

[mgarblik]

In a rules restricted class like NHRA Stock, you just have to work within them. The heads are so limited in flow, all you can do is open the valve as quickly as possible and keep it open as long as possible. Any duration allowed. You end up with rectangular cam lobes and hope for the best. Valve springs become super important. Lifters and cams don't last long.

[i82much]

Originally Posted by ponyakr

"...what flow numbers are possible from a 670 head with professional CNC porting? "

When I went back I read this, I decided to check on the SD CNC porting deal.

To my surprise, SD no longer fools with iron heads. I suppose I'm the last to know.

http://www.sdperformance.com/listPro...?categoryID=53

I suppose he has much more than he can do, with just alum heads.

So, who now has the best CNC program for iron Pontiac heads ?

Butler says they do more Pontiac heads than anybody else in the world.

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

I suppose there are several members here who do hand porting. I assume most members know who these guys are. Any who wish to advertise their porting services can. Don't know who now does a lot of CNC Pontiac iron head porting.

KRE shows lots of alum head CNC porting. But there is no mention, specifically, of porting iron heads.

http://www.krepower.com/Pontiac%20Cylinder%20Heads.htm

Nitemare shows Pontiac iron head porting services. Not a recommendation. Just a possible source.

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

Got this from a Google search.

https://headsandmanifolds.wordpress....-head-porting/

i’m not sure he always gets my sense of humor, but if i had a set of iron heads that i wanted ported I would PM steve25 and ask him if we could port them or, if not, who he would recommend. the guy seems to know his stuff.

[PAUL K]

Originally Posted by ponyakr

"... on a stock 670 head I got it to flow 225 to 228 cfm..."

So, you think Randi Lyn's '67 Stocker can run 10.50 or quicker, with no more flow than that ?

OR, do you think the heads have been "massaged" to flow more ? IF so, how much more ?

I understand about Stocker "tricks" & "set-up" to run quick. BUT, the engine still has to make a certain amount of power to run the big numbers.

SO, since this thread is about 670 head flow, there's no better place to include the 670 heads on an NHRA Stocker.

Aprox how much would heads have to flow in order for a 400 Pontiac engine to turn 8000 rpm ? Is that something you guys can calculate ?

Bryan Phillips also has a 10 sec '67 Bird Stocker. So, I assume his 670 heads also flow more than a non-ported factory stock set.

I have one for you; how fast do you think Mrs. Shipp's 400 would run in a stock 67 Firebird? Maybe assume a TH400 and the performance gear ratio.

[ponyakr]

Originally Posted by PAUL K

I have one for you; how fast do you think Mrs. Shipp's 400 would run in a stock 67 Firebird? Maybe assume a TH400 and the performance gear ratio.

Quicker than that same car with absolutely "as cast" ports, on otherwise identical heads, is my guess.

So, are you saying that the heads on her engine have absolutely "as cast" ports ? Hey, I'm asking. I don't know. There's no possible way I could know.

It's just my thinkin that these 1st gen Pontiac Stockers couldn't run low 10's with D-port heads, which have untouched, "as cast" ports.

Don't it take around 500hp or more to run these times/speeds ? Will a legal '67 Pontiac 400 Stocker engine make 500hp ? More ? How much ?

To me, these are legitimate questions. I don't have a clue how to calculate the answers. But, I assume that some here can.

[ponyakr]

Since I brought it up, I feel obligated to post a little more info about Randi Lyn & her '67 Bird Stocker. Here are some quotes from the article, linked below the quote.

"...Running at 3,210 lbs. (with driver) in D/SA (11.55 index), the Pontiac has run 10.40 at 124 mph. And when set up lighter for C/SA, it's run a best of 10.31 at over 125 mph...

Amazingly, the Poncho sings to 6,800 before she clicks the gears, and it buzzes across the stripe where no Pontiac should go—revving to 7,800-8,000 rpm!...

rated by Pontiac at 325 hp and factored to 338 hp by NHRA. It's meticulously prepared to take full advantage of the Stock Eliminator guidelines and produces north of 500 hp..."

https://www.motortrend.com/features/...1967-firebird/

The article was published back when she only had 4 nat event wins. I think she now has 7. But, I don't think she's married yet. So, she's still "Miss" Shipp, & has never been "Mrs. Shipp". LOL

There are lots of pics in the article. One of 'em shows that the engine does indeed have 670 heads. And I assume she revealed the 500+ hp number, because she's seen the dyno numbers.

So, bottom line is that she shifts @ 6800, crosses @, or very near 8000, makes over 500hp, & has run quicker than 10.50's.

She even provided the ET, top speed, & total weight numbers, so you guys who know how to calculate stuff can do your thang.

Randi Lyn seems like a real nice lady, and their whole racing operation seems to be 1st class. So, she & her Pontiac are a couple of my favorites.

But, with all that said, I still don't have a clue if those 670 ports are "as cast", or not.

Here's another article, with less technical info.

https://dragchamp.com/2020/nhra/stoc...ndi-lyn-shipp/

https://dragchamp.com/2019/nhra/stoc...-66-nationals/

https://www.facebook.com/rlshipp

[sdbob]

My exp with my stk parts SD455,35 yrs ago. Car weighs approx 3740. Heads were done by AHines Racing out of Lawrence burg Ind. He was doing engines for different Pontiac guys. Anyways I had some input from John Herslow.John said to run 4.56 gears. I tried them with basic slapper bars. Car was spinning,i tried adjusting shocks ex.just couldnt get good consistent times. So I put 4.10s in got car to 12teens at 110. Still not good. He had gone 11.70s. So we talked. He gave me a cam that he said went the fastest with,however he said car was popping through carb. I have cam but was afraid to use it. My point being you need all the dyno time, testing in car to find what works.Another you could estimate hp, work backwards car weight,mph get ball park figure for required hp. I do think heads are modified with acid to get the flow for the hp. I'm satisfied at my age if I was younger I would test different ideas. Automatic trans are in the $5k range I've been told,gulp! for me. Testing ,more testing.i will tell you for my SD that the qjet 2nd metering rods are very very thin,I picked up when I did that the engine wants fuel.

[PAUL K]

Originally Posted by ponyakr

Quicker than that same car with absolutely "as cast" ports, on otherwise identical heads, is my guess.

So, are you saying that the heads on her engine have absolutely "as cast" ports ? Hey, I'm asking. I don't know. There's no possible way I could know.

It's just my thinkin that these 1st gen Pontiac Stockers couldn't run low 10's with D-port heads, which have untouched, "as cast" ports.

Don't it take around 500hp or more to run these times/speeds ? Will a legal '67 Pontiac 400 Stocker engine make 500hp ? More ? How much ?

To me, these are legitimate questions. I don't have a clue how to calculate the answers. But, I assume that some here can.

My mistake I though she was married to Bo.

What you are asking in regards to the CFM it would take to run mid tens in her car is going to be tough to figure out. There is a whole lot more going on with the rest of the car than just what's under the valve covers (as you know). If you knew what the engine would run in a stock Firebird or known chassis it'd be easier to base line the power their engine is making.

I don't know enough about their combo to venture a guess. I'm certain, based on my past experiences is a lot of "class" racers seem to think ten horsepower that they paid $5k for is a better than ten horsepower they can buy for $500.... Regardless they do manage to squeeze a lot of ET out of their combinations. I'm glad a handful of them are flying the Pontiac banner with success after all these years.

[Stan Weiss]

Originally Posted by ponyakr

For all you head flow experts, & guys who know how to calculate power related to ET, here's a question.

I assume Randi Lyn Shipp's '67 Bird Stocker runs 670 heads.

The car has run quicker than 10.50, on several occasions.

So, although the NHRA Stock rules call for no porting, how much head flow is required for that car to run 10.50 ?

These old school Stocker combos that can run low 10's & high 9's & are quicker than the same combo was in SS form, back in the '70's, are very interesting to me. I know the unlimited valve spring pressure & cam duration play a big part. But, I don't think that MOST "as cast" factory heads will flow enuff to run the big numbers some are running today. Assume some form of "porting", which would have been illegal back in the old days.

Have read all sorts of methods that have been used to increase flow, such as acid porting, inducing rust, & even hand porting, and then covering it up, in various ways, so that it's hard to detect. Assuming that NHRA finally just gave up & decided to let it go. Have read that "Heads-Up" builds some of the very best flowing Stocker heads. There WAS a section on their site, vaguely describing their Stocker head port enlarging modification. But, that section disappeared, as of the last few times I tried to find it. The Stock section just says "Under Construction".

https://www.headsupcylinderheads.com...der-heads.html

Since all any of us can do is guess. I would say around 220 CFM for the intake.

Stan

[Jay S]

You are correct Don, I was using the 67 400 RA rating and forgot to add the 170 lbs on for the driver and min rating weights. But the 120 mph was from when I watched the car go down the track, 120 to 121 was what I watched. From those better numbers you listed I come up with 528 hp, recalculating that is likely at most a 253 cfm head using the .26 super flow number. I doubt though that the .26 is correct, likely .28 or more on a stocker, I am guessing the head flow in the 230s. Can’t really compare stock and SS to other porting that does not have to meet port volume criteria for class rules.

X3 on using mph and not et

[ponyakr]

"... the 120 mph was from when I watched the car go down the track, 120 to 121 was what I watched..."

Yeah, with the NHRA hp police being on duty, at most big races, most of the quick cars sand bag, so their combo won't get a horsepower hit.

A quick search turned up a D/SA speed of 124.06 mph, for Randi Lyn, @ Indy, in August. She was more than a sec under, but had to settle for D/SA class RU. The D/SA winner was more than 1.2 under, which would have earned a hit from NHRA, this year. The US Nats race has been exempt in recent years, but not this year.

https://www.dragracecentral.com/DRCS...r2019#indextop

Look how even the quick cars were very careful to NOT go 1.2 under, this year.

https://www.dragracecentral.com/DRCS...r2021#indextop

At most races, a time of 1.20 or more under the index will get the combo an automatic hp hit.

I've read that some just add a bunch of weight. Some short shift. Some let off early. Some detune. Some use some combination of 2 or more of these methods.

So, Randi Lyn will not be running near as quick as the car is capable of, at MOST races.

Same goes for all the Stock/SS cars that can run 1.20 or more under.