Great Bend Stock DQ

[Bernie Cunningham]

Word has it that the stocker volumes are very close to been done ( upwards of 90+%) and that we'll see 'em published around Indy time. Everybody, just hold ya breath until then! LOL
The way I figure it, those numbers will give us some 'lines to paint between'. However, I'm still concerned about the runner surface texture that can be positively identified as a stock surface. Should it match the texture of another outside surface, i.e. inside the head under the valve cover , around the valve springs?????
There's plenty of recent technology that can measure the texture and it wouldn't be that difficult for NHRA to step up to the plate and purchase such instruments i.e. a profilometer. An industy standard method of checking for welds and acid has been around for sometime now, it really is not that hard to detect!

Disclaimer: I'm a bit of a dinosuar racer, meaning my heads are completely untouched, give me some specs and checking methods and that'll probably change!

[SSDiv6]

Originally Posted by Bernie Cunningham

Word has it that the stocker volumes are very close to been done ( upwards of 90+%) and that we'll see 'em published around Indy time. Everybody, just hold ya breath until then! LOL
The way I figure it, those numbers will give us some 'lines to paint between'. However, I'm still concerned about the runner surface texture that can be positively identified as a stock surface. Should it match the texture of another outside surface, i.e. inside the head under the valve cover , around the valve springs?????
There's plenty of recent technology that can measure the texture and it wouldn't be that difficult for NHRA to step up to the plate and purchase such instruments i.e. a profilometer. An industy standard method of checking for welds and acid has been around for sometime now, it really is not that hard to detect!

Disclaimer: I'm a bit of a dinosuar racer, meaning my heads are completely untouched, give me some specs and checking methods and that'll probably change!

Bernie, the problem is that surface texture is subjective, especially when the OEM used various foundries. Also, the condition of the tooling and molds has a lot to do with surface texture and also with core shift. With the exception of aluminum heads, you will see always a variation of surface texture in cast iron heads. I have seen this with many different makes of cast iron cylinder heads.

So, if NHRA starts to use a profilometer, who is going to establish the values and surface finish criteria? The surface finish criteria is different for all OEM's. Who is going to send the NHRA staff to train in metrology? The fact is that you do not need to have a smooth surface to make power with a low lift application. The new valve rule is what you will see as the one of the items improving performance in the class. About acid, there are numerous ways to neutralize and remove all traces of acid from cast iron and aluminum making it undetectable.

I am more worried of metal spraying than acid; hogging out a port is not the only key of making power: the shape of the port and runner is the key for velocity and to power. ...and no, you are not a Dinosaur racer; you have many valid points. The problem is that NHRA cannot keep up with either the technology that is available and the creativity of racers.

[Bill Grubbs]

Not speaking for Bernie, but I believe he was inferring that if the runner texture does not match the other "cast" textures on the same head there "may" be a problem. For instance, in a 441 SBC head if the textures of the runners is not the same as the texture on of the cast surface under the valve cover, or the exterior of the runner on the underside of the head, then there "may" be a problem. Therefore if you were to do some runner "work" you would have to re-work all the cast surfaces on the head (time and $$$).

Bill

[SSDiv6]

Originally Posted by Bill Grubbs

Not speaking for Bernie, but I believe he was inferring that if the runner texture does not match the other "cast" textures on the same head there "may" be a problem. For instance, in a 441 SBC head if the textures of the runners is not the same as the texture on of the cast surface under the valve cover, or the exterior of the runner on the underside of the head, then there "may" be a problem. Therefore if you were to do some runner "work" you would have to re-work all the cast surfaces on the head (time and $$$).

Bill

Bill, like I said, racers are creative. Racers have got around it by glass beading or shot peening the whole cylinder head. One of the items I would suggest is making port templates based on available, over-the-counter gaskets. Mr. Gasket even has a set of templates based on their Ultra Seal line.