|
12-11-2008, 08:22 AM | #1 |
Senior Member
Join Date: Jun 2007
Posts: 917
Likes: 461
Liked 167 Times in 64 Posts
|
2009 NHRA Rules
I received my rulebook yesterday and noticed under the cylinder head paragraph that it now states "any valve job permitted" without the 1/4" below valve seat cut being mentioned. Is this a typo error ? Does anybody have input on this. How about it Travis Miller,can you give us some guidance on this ?
__________________
Mike Fuller 396 STK |
12-11-2008, 07:42 PM | #2 | |
Member
Join Date: Jun 2007
Posts: 476
Likes: 1
Liked 275 Times in 25 Posts
|
Re: 2009 NHRA Rules
Quote:
Travis (Disclaimer: Opinions expressed by me on this forum are exactly that, my opinions.) |
|
12-12-2008, 12:24 AM | #3 |
Senior Member
Join Date: Apr 2003
Location: Aberdeen SD
Posts: 643
Likes: 29
Liked 105 Times in 29 Posts
|
Re: 2009 NHRA Rules
I don't know!!! My 2009 Rulebook states on page 104 under CYLINDER HEADS, "Cylinder heads are additionally restricted in that they must retain original-size valves at original angles +/- 1 degree and must be able to hold original head volume per NHRA Specifications." That kinda contradicts their "any valve job accepted" statement on the bottom of the section doesn't it?
In Superstock on page 114 under CYLINDER HEADS, it says, "Valves must retain stock angle; valve-stem angle, +/- 1 degee." Again, toward the bottom of the section, "Any valve job accepted". I'm mystified? All this stuff was supposedly superceded by NHRA in prior year revisions; the wording under CYLINDER HEADS in both Stock and SS is different in the 2009 rules compared to those of 2008, yet when they revised the CYLINDER HEAD section, they failed to remove the contradictions of their own revisons when writing the 2009 Rulebook. Who proof-reads this s--t? Or doesn't "ANY" really mean "ANY" with respect to original valve/seat angles? Jerry |
12-12-2008, 11:23 AM | #4 |
Member
Join Date: Dec 2006
Location: Indy
Posts: 422
Likes: 0
Liked 0 Times in 0 Posts
|
Re: 2009 NHRA Rules
Jerry, that angle referenced would be the actual valve to deck angle,
I.E.> 23 degree SBC valves must stay within + or - 1 degree, so no relocating the guides or angle milling to roll the valve angle. The wording would indicate that you cannot alter the area beyond the valve seats, which can now be replaced. ???? The spec used to require that that original valve / seat angles and restricted how many angles you could put on the valves / seats, and the width of the margins and the seat angles.
__________________
"Despite the high cost of living, it remains popular." Dave Cook NHRA N375 |
12-12-2008, 03:05 PM | #5 |
Senior Member
Join Date: Apr 2003
Location: Aberdeen SD
Posts: 643
Likes: 29
Liked 105 Times in 29 Posts
|
Re: 2009 NHRA Rules
Dave,
It may be what you think, but the average guy is thinking of valve jobs as valve jobs. Also, the paragraph regarding Superstock references both STOCK ANGLE, and the +/- 1 degree (my second paragraph - quote on page 114), so I believe you're interpretation is incorrect. Yes the valve angle/deck surface relationship will change with angle-milling and NHRA is aware of that, but then they wouldn't need to include "STOCK ANGLE" in that paragraph. It's still a contradiction. Jerry |
12-12-2008, 03:34 PM | #6 |
Member
Join Date: Feb 2005
Location: Dayton, MD
Posts: 222
Likes: 0
Liked 1 Time in 1 Post
|
Re: 2009 NHRA Rules
You can't angle mill a head enough to change the valve angle more than a degree or should I say, you can but the head wouldn't be useable... what they don't want you doin is reboreing the guides to change the angle
|
12-13-2008, 08:42 AM | #7 | |
Member
Join Date: Aug 2002
Location: Pierre, SD
Posts: 199
Likes: 0
Liked 25 Times in 13 Posts
|
Re: 2009 NHRA Rules
Quote:
The "for acceptable valve job, see General Regulations 1:2 illustration" was also removed as part of last January's rules revisions. HOWEVER, the 2008 Rules Revisions have already been removed from the NHRA website, as the 2009 Rules Revisions are up. Last edited by Dean Feiock; 12-13-2008 at 09:03 AM. Reason: Spelling |
|
12-13-2008, 11:56 AM | #8 |
Member
Join Date: Dec 2006
Location: Indy
Posts: 422
Likes: 0
Liked 0 Times in 0 Posts
|
Re: 2009 NHRA Rules
Umm, my Pontiac 867 heads are angle milled to 20.5 degrees.....while maintaining the chamber cc's
__________________
"Despite the high cost of living, it remains popular." Dave Cook NHRA N375 |
12-13-2008, 01:24 PM | #9 |
Senior Member
Join Date: Jul 2007
Posts: 805
Likes: 0
Liked 3 Times in 1 Post
|
Re: 2009 NHRA Rules
Bub, you are right on again,,,,,,,i vote for you as Tech Director!!!!!! lol
__________________
Woodro Josey 2002 STK |
|
|