Don Terrill’s Speed-Talk

Cryo is basically a form of heat treating. Will relieve stresses in the material so dimensions may change just a bit. And the metal needs to be heat treatable which mild steel isn't.

Toe in aids stability while toe out makes for searching back and forth as first one wheel and then the other becomes the dominant steering wheel.

The “experts” don’t help. “Beg the question” is a term of art describing faulty logic. Commentators heard its use by the better educated and, not knowing its meaning, butchered its use.

Got the same problem. Often the two-piece plugs can be removed by using an air wrench with torque set below that speced. By rattling away at the plug the carbon deposit that is the source of the problem chips off allowing removal.

As for the effects achieved by dimpling or other surface 'imperfections' I believe we still have a lot to learn. Right now where I am at is to use those course grit rolls so the ports have a roughish finish. No port polishing in my shop - but I am watching what Larry and Chad do very closely!! DV R...

I doubt that it would make much difference on the intake side. However, at exhaust temperatures the exhaust viscosity is a good bit higher than at ambient temperatures.

Keep in mind that zoomies can generate substantial exhaust thrust. This can add useful downforce before the aero comes into play. Picking up a few MPH of the line works for you all the way down the strip.

And they look good too.

I'm sure super trapps have their place on engines, maybe a 2 stroke or a dunebuggy or something. I can't ever remember seeing many of them at our local drag strips. An occasional street rod or two I've seen them on. There is probably a reason for it. Krooser we are just saving you the embarrassment...

statsystems wrote:[The rings only see cylinder pressure on the compression stroke. The rest of the time they are just using radial tension.

Maybe the power stroke.

If there was anywhere this would be beneficial a high speed ssr comes to mind. If surface texture would help the air stay attached at higher speed before separation that would make a ssr that is shape challenged perform better. condition If you "trip" the boundary layer to a turbulent con...

If I may suggest , before you button those heads up your should add texture back to all the polished out surfaces on the Intake ports, a 40 grit slow spun Cartridge roll , or a fine cut Burr on a slower speed is what I use. These heads have only polishing on the ssr surface. Everything else I do wi...

nhrastocker wrote:

RCJ wrote:What about the natural frequency of aluminum vs. steel?

There is not a standard natural frequency.
There are too many alloys and finishes that have an impact on the natural frequency.

The point may be the damping of the material. Aluminum won't ring like steel -but more than magnesium.

Perhaps pertinent; I was driving an excellent -very light traffic- interstate at about 90mph when I sensed a very slight twitch by the car. Upon slowing to 60 (parked) ever thing was normal. Shortly thereafter I crested a rise and came upon over a dozen badly wreaked vehicles. Some had plowed throug...

Thermal conductivity is predicted by the following formula: Q = k A d T / D where A = area d T = temperature difference D = thickness of coating k = thermal coefficient Since the area and temperatures are fixed, only k and thickness determine thermal conductivity. Some examples of k for various mat...

PackardV8 wrote:Generally, 60' is chassis, tires, gears, flywheel/stall and lowest weight. MPH is highest horsepower/lowest CD and ET is best combination of all the above.

Maybe CoG, both height and fore-aft, too.