Runner Volumes

Mike Pearson · 01-06-2009, 11:10 AM

Hey Daran. Jay Slane had similar results with a set of 441 heads that he is working on. All of the small block heads that I have CC'd before porting have come up about 6 CC's smaller than the SS limit. I am not sure how that compares with big block or other brands. NHRA will probably just allow some mild porting and epoxy in the intake and welded exhaust like SS. They couldnt control the head rule in super stock so they changed the rules. They will probably do the same for stock. Then a good set of heads will cost 7500.00 but you wont have to worry about passing teardown. As long as the valve size is correct and the CC's are right you will pass.

Woodro Josey · 01-06-2009, 11:14 AM

Daran, FYI, there are 2 different castings in the 441's one type is bigger on intake runners than the other!

Lyn Smith · 01-06-2009, 11:38 AM

Why dont they just add 2 or 3 percent to all the SS volumes,and use that for both the STK and SS numbers? They should only have one list.Will be alot less confusing when you race a stocker in SS.

greg fulk · 01-06-2009, 01:05 PM

I have to agree with Lyn...their are alot of guys that run both S & SS with the same car. I also have a question on the head volumes...what about the cars that have NO #'s like our 6cyl nova? I don't see any #'s for a 230!

Tony Curcio · 01-06-2009, 06:01 PM

DARAN:

161 CC is the spec for the intake side. My intakes were safely under the spec as well.

It's the exhaust side that is way too close for comfort. Same result now on 3 sets.

SPS · 01-06-2009, 06:56 PM

Who's to say the numbers used for Super Stock are really "right" anyway.
I'm sure no scientific methods were ever used to arrive at the magic numbers we have to use.
As Woodro says , there are different castings made at different foundries that definately have different volumes when made.
I for one like Lyn's idea to add 2 or 3 percent and get on with it.

FJ

Adger Smith · 01-07-2009, 02:42 AM

Just a little insight to the production of heads. My buddies at Brodix tell me that a fresh core box will produce heads that are on spec. I assume that means port location & cc's because they say at the end of a production run the core boxes are showing wear & the port volumn will be smaller than designed. I would think the same applies to any automaker produced heads. The Design/R&D guys at Brodix have used the term "Filed" core when talking about producing a bigger runner head. Hey, the pattern maker has a bad day on Monday & the molds are off spec. He sobers up by Wed and is feeling good so he makes some molds over spec. At that time of original design & production little did they know that the quality of their work & a few CC's would mean so much to racers.

01-06-2009, 11:10 AM	#1
Mike Pearson VIP Member Join Date: Mar 2007 Posts: 2,444 Likes: 613 Liked 1,916 Times in 574 Posts	Re: Runner Volumes Hey Daran. Jay Slane had similar results with a set of 441 heads that he is working on. All of the small block heads that I have CC'd before porting have come up about 6 CC's smaller than the SS limit. I am not sure how that compares with big block or other brands. NHRA will probably just allow some mild porting and epoxy in the intake and welded exhaust like SS. They couldnt control the head rule in super stock so they changed the rules. They will probably do the same for stock. Then a good set of heads will cost 7500.00 but you wont have to worry about passing teardown. As long as the valve size is correct and the CC's are right you will pass. __________________ Mike Pearson 2485 SS

01-06-2009, 11:14 AM	#2
Woodro Josey Senior Member Join Date: Jul 2007 Posts: 805 Likes: 0 Liked 3 Times in 1 Post	Re: Runner Volumes Daran, FYI, there are 2 different castings in the 441's one type is bigger on intake runners than the other! __________________ Woodro Josey 2002 STK

01-06-2009, 11:38 AM	#3
Lyn Smith VIP Member Join Date: Dec 2001 Location: Pontiac,il. Posts: 1,198 Likes: 281 Liked 963 Times in 193 Posts	Re: Runner Volumes Why dont they just add 2 or 3 percent to all the SS volumes,and use that for both the STK and SS numbers? They should only have one list.Will be alot less confusing when you race a stocker in SS.

01-06-2009, 01:05 PM	#4
greg fulk VIP Member Join Date: Jan 2003 Location: jackson Posts: 1,165 Likes: 0 Liked 5 Times in 3 Posts	Re: Runner Volumes I have to agree with Lyn...their are alot of guys that run both S & SS with the same car. I also have a question on the head volumes...what about the cars that have NO #'s like our 6cyl nova? I don't see any #'s for a 230! __________________ Greg Fulk 308 308X P/SA "ALL AMERICAN"

01-06-2009, 06:01 PM	#5
Tony Curcio Member Join Date: Mar 2002 Location: West Chester, PA Posts: 271 Likes: 1 Liked 4 Times in 1 Post	Re: Runner Volumes DARAN: 161 CC is the spec for the intake side. My intakes were safely under the spec as well. It's the exhaust side that is way too close for comfort. Same result now on 3 sets. __________________ Tony Curcio 1860 STK

01-06-2009, 06:56 PM	#6
SPS Member Join Date: Jun 2004 Location: Cayuga, Canada Posts: 298 Likes: 37 Liked 3 Times in 2 Posts	Re: Runner Volumes Who's to say the numbers used for Super Stock are really "right" anyway. I'm sure no scientific methods were ever used to arrive at the magic numbers we have to use. As Woodro says , there are different castings made at different foundries that definately have different volumes when made. I for one like Lyn's idea to add 2 or 3 percent and get on with it. FJ

01-07-2009, 02:42 AM	#7
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,446 Likes: 575 Liked 880 Times in 311 Posts	Re: Runner Volumes Just a little insight to the production of heads. My buddies at Brodix tell me that a fresh core box will produce heads that are on spec. I assume that means port location & cc's because they say at the end of a production run the core boxes are showing wear & the port volumn will be smaller than designed. I would think the same applies to any automaker produced heads. The Design/R&D guys at Brodix have used the term "Filed" core when talking about producing a bigger runner head. Hey, the pattern maker has a bad day on Monday & the molds are off spec. He sobers up by Wed and is feeling good so he makes some molds over spec. At that time of original design & production little did they know that the quality of their work & a few CC's would mean so much to racers. __________________ Adger Smith (Former SS)

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