Stocker Cylinder Heads....

[James L Miller]

I seem to remember the Mopar 340 specs at 336/348 duration intake/exhaust respectively. I think the 383/440 HP combos had a similar duration way back when. I wasn't sure if it was zero to zero or maybe the first hint of movement to where it stops moving? I sort of remember a BB Chevy cam had 360 degrees of duration.

[Tom keedle]

Originally Posted by Run to Rund

I read somewhere that early stocker "cheater" cams were made from cams with a lot more lift, cut down to allowable, and the sharp corners were rounded with a belt sander just enough that the engine could get the rpm it needed.

sounds like the cam i've got...

[Greg Reimer 7376]

Dwight-- That was interesting. Nothing woke up those early SBC's more than good short block assembly and the right camshaft. Any more hisory lessons out there?

[SS Engine Guy]

Originally Posted by Dwight Southerland

3) Alan, your explanation of the characteristics of a legal valve job will never fly. I'm not saying you were not told that, but if that's their (NHRA) assumption, it needs to be in writing. I see nothing in the current rule book that gets even close to the description you gave.

I have been given the same explanation as Alan and also in writing (for what little that is worth). 3 thru tech with not a word said and never used the letter. The only thing I was told that wouldn't fly was a radius valve seat. (which I don't use) However, I have seen them go thru tech also. I think this disinformation is what Wade is trying to clear up.
There is some hp directly behind the valve if work is done correctly. I would think that .250 thou. below the seat would be all that should be allowed in stock. Anything more I would consider a form of pocket porting.

[Alan Roehrich]

Originally Posted by SS Engine Guy

I have been given the same explanation as Alan and also in writing (for what little that is worth). 3 thru tech with not a word said and never used the letter. The only thing I was told that wouldn't fly was a radius valve seat. (which I don't use) However, I have seen them go thru tech also. I think this disinformation is what Wade is trying to clear up.
There is some hp directly behind the valve if work is done correctly. I would think that .250 thou. below the seat would be all that should be allowed in stock. Anything more I would consider a form of pocket porting.

Well, 0.250" below the stock valve seat angle was the rule until they opened it up. Now there is supposedly no limit on the number of angles, and I was told 0.500" below the seat angle would pass. I was told a radius seat was legal as well, I just have not had time to try one, yet.

[Dwight Southerland]

Originally Posted by Alan Roehrich

Well, 0.250" below the stock valve seat angle was the rule until they opened it up. Now there is supposedly no limit on the number of angles, and I was told 0.500" below the seat angle would pass. I was told a radius seat was legal as well, I just have not had time to try one, yet.

If they allow .5" below the seat, we are all in for some big surprises. They might as well get some templates to check for an acceptible port opening location and size, pour the port and let it go.

[Dwight Southerland]

Originally Posted by Greg Reimer 7376

Dwight-- That was interesting. Nothing woke up those early SBC's more than good short block assembly and the right camshaft. Any more hisory lessons out there?

Yeah, Don't ever let anyone check your camshaft using a piece of masking tape wrapped around the balancer, a ball point pen to mark opening and closing and then measuring the distance between the marks to calculate duration.

[Greg Hill]

In 2008. I was the d3 srac member when the rule was changed to permit any valve job. I was told by three different senior tech people that you could do anything in the bowl as long as it was done off the center of the valve guide with a cutter. Alan is exactly right that the rule was .250 down before the rule change. Any of you talk to engine builders or head guys and they will tell you the same thing. A lot of people who post on here don't like all the changes in stock over the years. That's not relevant to this discussion.

What's needed are fair and consistent rules that are enforceable no matter who is looking at the heads. With the technology that is available to anyone who's willing to spend the money, it's my feeling that to get to fair and consistent rules there have to be things that can be measured. When one person can say, " I don't like the way that looks" and give no other reason for disqualification that opens up the door for favoritism or vindictiveness. I know for a fact some engine builders and head guys have been told that if the heads pour right and there are no grinding marks they are ok. I think to get enforceable rules they should allow porting with no welding or epoxy and that the heads should hold the right number of cc's in the runners.

I realize some of you would not like to see that change but given where we are right now I see no other way to have rules that are fair and enforceable.

[Adger Smith]

I was told that the "NEW" Legal valve job did away with the unshrouding rules (1/8 bigger than valve head) and the 1/4" (Seat) part of the rule.
Basically if you can do it "On center of the valve guide" it will pass. It doesn't matter if it is in the bowl area or chamber area as long as it is "On center of the valve guide Center Line. The only exception I got, if you want to call it that, was when I ask if anything could be "elliptical" The answer I got to that was a definition of "on center". I'm pretty sure that last line just gave away who was giving me the Vale Job information. I would bet quite a few of you know his "Style"... of giving answers.

[Dean Feiock]

I have added a poll in the member's area, just for fun.
http://classracer.com/classforum/showthread.php?t=41556