Valve seat angles in stock

jmantle · 12-31-2008, 08:58 PM

Just got my 2009 NHRA rule book, the cylinder head section in stock says stock angles plus or minus 1 degree. I had heard the "any valve grind permitted" was coming but the stock angle thing was a surprise. This should be interesting with some of the "approved" aftermarket heads where the angles don't match OEM.

JRyan · 01-01-2009, 12:43 AM

jmantle,

This was covered in an earlier thread, around 12/11/08, entitled "2009 NHRA Rules". Dave described what NHRA meant, but you're living proof of what I said about "the average guy is thinking about valve jobs as valve jobs", not the valve angle/deck surface relationship NHRA is refering too. If that's what they mean, then that's what they should say. Thanks!

Read the thread and see what you think.

Jerry

stealy perf mach · 01-01-2009, 01:08 AM

jerry
what they need to say is valve guide/stem angle in relation to deck surface or no valve guide relocation

jeff stealy

JRyan · 01-01-2009, 03:13 AM

Jeff,

I agree! A new guy reading the rules for valve/seat angles in either Stock or Superstock would have no idea that they're refering to valve guide location or should I say re-location. I know!! I've asked several people to read those sections of the rules and NONE picked up on guide relocation.

Jerry

Bud Lefevre · 01-01-2009, 05:01 AM

So , what is legal in stock ?

bill dedman · 01-01-2009, 10:48 PM

Since when has that rule book been clear about ANYTHING? It is case study in obfuscation and self-contrdiction. I think they write it deliberately vague so they can interpret it according to the whim of the moment of the tech doing the decision-making.

I'm serious; it's a joke.... but, the joke's on the racers.

What a shame...

JRyan · 01-01-2009, 11:06 PM

Bill,

You may be right. I don't know as it's NHRA's intention, but it can be made to work as they wish. So how do they know if a valve job is illegal. As Supreme Court Justice Potter Stewart (thank Jared) said with regard to pornography, "I can't describe it, but I know it when I see it". NHRA takes the same view on valve jobs.

Really! Bud's question has been up most of the day. Does anyone have a descriptive answer for him?
I don't.

Jerry

12-31-2008, 08:58 PM	#1
jmantle Member Join Date: Feb 2008 Location: Black Creek, BC Canada Posts: 329 Likes: 75 Liked 169 Times in 80 Posts	Valve seat angles in stock Just got my 2009 NHRA rule book, the cylinder head section in stock says stock angles plus or minus 1 degree. I had heard the "any valve grind permitted" was coming but the stock angle thing was a surprise. This should be interesting with some of the "approved" aftermarket heads where the angles don't match OEM.

01-01-2009, 12:43 AM	#2
JRyan Senior Member Join Date: Apr 2003 Location: Aberdeen SD Posts: 645 Likes: 30 Liked 112 Times in 31 Posts	Re: Valve seat angles in stock jmantle, This was covered in an earlier thread, around 12/11/08, entitled "2009 NHRA Rules". Dave described what NHRA meant, but you're living proof of what I said about "the average guy is thinking about valve jobs as valve jobs", not the valve angle/deck surface relationship NHRA is refering too. If that's what they mean, then that's what they should say. Thanks! Read the thread and see what you think. Jerry

01-01-2009, 01:08 AM	#3
stealy perf mach Junior Member Join Date: Feb 2008 Location: east moline il Posts: 7 Likes: 0 Liked 0 Times in 0 Posts	Re: Valve seat angles in stock jerry what they need to say is valve guide/stem angle in relation to deck surface or no valve guide relocation jeff stealy __________________ jeff stealy

01-01-2009, 03:13 AM	#4
JRyan Senior Member Join Date: Apr 2003 Location: Aberdeen SD Posts: 645 Likes: 30 Liked 112 Times in 31 Posts	Re: Valve seat angles in stock Jeff, I agree! A new guy reading the rules for valve/seat angles in either Stock or Superstock would have no idea that they're refering to valve guide location or should I say re-location. I know!! I've asked several people to read those sections of the rules and NONE picked up on guide relocation. Jerry

01-01-2009, 05:01 AM	#5
Bud Lefevre Member Join Date: Mar 2002 Location: Toledo, Ohio Posts: 250 Likes: 0 Liked 0 Times in 0 Posts	Re: Valve seat angles in stock So , what is legal in stock ? __________________ Bud Lefevre 3075 STK IHRA World Record Holder

01-01-2009, 10:48 PM	#6
bill dedman VIP Member Join Date: Feb 2002 Location: Conway, AR Posts: 1,739 Likes: 0 Liked 6 Times in 4 Posts	Re: Valve seat angles in stock Since when has that rule book been clear about ANYTHING? It is case study in obfuscation and self-contrdiction. I think they write it deliberately vague so they can interpret it according to the whim of the moment of the tech doing the decision-making. I'm serious; it's a joke.... but, the joke's on the racers. What a shame... __________________ Bill

01-01-2009, 11:06 PM	#7
JRyan Senior Member Join Date: Apr 2003 Location: Aberdeen SD Posts: 645 Likes: 30 Liked 112 Times in 31 Posts	Re: Valve seat angles in stock Bill, You may be right. I don't know as it's NHRA's intention, but it can be made to work as they wish. So how do they know if a valve job is illegal. As Supreme Court Justice Potter Stewart (thank Jared) said with regard to pornography, "I can't describe it, but I know it when I see it". NHRA takes the same view on valve jobs. Really! Bud's question has been up most of the day. Does anyone have a descriptive answer for him? I don't. Jerry