Well, I do the double Groove, Sometimes. But not every time. It requires one of the reverse bits from the Certified Gasgetman bit set. Only a few of those type exist. There is another new idea though, and any Gadgetman can try it.
In the message thread on the GM 4.3 Vortec Groove jobs in the forum right now:
scroll down to see the pics Juan Reyes, a new Gadgetman, posted of his vortec 4.3L V6 TB. Juan started this thread, and then Victor M, in Alaska, jumped into it with HIS Grooved TB, the same kind. so it's actually 2 different TB's and guys in that thread. Juan did a stellar job with his TB, probably the best looking Groove job I've seen yet. Anyway, look at the small round "dimples" he cut into the bore wall. This idea is the principle of the Dimples as found on golf balls.
Juan is real happy w/ his results on his 4.3L Vortec. these shallow dimples are done w/ a small ball cutter, Dremel has a few different sizes of 'em. they are cheap. (I wouldn't try making them w/ a Gadgetman bit, it won't work!) Anyway, this is new and real Experimental now.
Juan sent me some info re: research being done in some high level Machine shop somewhere. Doing dimple cuts all over inside cylinder head ports. It was unintelligible, in Spanish I think. The visuals I got seeing the research website, plus others about golf balls, leads me to the theory that involves altering airflow characteristics. It leads me to think that these dimples, will cause an increase in air density along the boundary flow area in the TB. The air that is "sticking" to the bore walls. The increase in density is from tiny vortices that form in and close to the dimples as air passes over. Now, I'm still groping to understand this. My theory is that the boundary layer may become "thicker" at certain air speeds, or flow rates. Dynamic, in other words. I think there may be two possibilities here:
The denser boundary layer air, may increase the density and strength of the vortices inside the Groove cavity. By making the boundary layer air that spills into the upstream edge denser. And/or- the boundary layer air, IF that layer becomes more prominent, extending out further into the inside diameter of the bore. Meaning- if that boundary layer gets "thicker" relative to the undisturbed flow inboard of it...it just might, act as a dynamic restriction. IF I'm right here, and it works like I Think, it might act to make the inner air, the air inboard of that boundary layer, speed up due to dynamic restriction. That in turn, may help improve airflow into the intake manifold, and improve cylinder filling, at lower intake valve lifts. By increasing airflow Velocity, in the air inboard of this boundary layer. It's like having a TB bore that changes I.D.
OR- I'm wrong.
Part of my thinking here, comes from experiments and research done years ago by Mike Holler, who Ron was visiting in 2012. Mike is a real guru. He was doing custom mods of cylinder heads and a lot of fancy port work, using a flow bench. His work, involved making certain cuts in the intake ports, to cause this dynamic boundary layer flow like I'm speaking of. His cuts were parallel lines in appearance in a special orientation. I know not quite enough to be dangerous, and have some imagination.
No one I'm aware of has yet researched using these dimple cuts as before/after. But, go look for stuff that explains what the dimples on a golfball are there for. They create a high pressure zone around the golfball as it flies thru the air. Acting to decrease drag, making the air flow around the golfball better. They are a well proven idea, you would not see 'em on golfballs otherwise. The dimples cause an increase in pressure in a thin boundary layer that sticks to the golfball's surface, as it flies.
My point is-- if there is merit in this idea, it's pretty easy to do, the Dremel cutters exist and are cheap. Juan Reyes did it, and he just may have opened the door to a new technique for us!
So, my hat is again off to Juan Reyes, who may be the smartest Gadgetman in years!!
Juan you get Free Parking here from now on!!
So,TnCarMan, you see, we've not been idle!
On the moisture in the crankcase in winter from the PCV mods-- I'm with you. I'm trying to think of a way to reduce/eliminate that without using manifold vacuum. A catch can or oil separator helps, but doesn't eliminate the moisture fully when using the PCV Re-route.
Tracy G