Head dimpling

[DUK]

We use to dimple (small divits, like a golf ball) the chambers on air cooled engines in the past. Has anyone tried this and found any improvement mileage or power wise on a porsche?

[john walker's workshop]

it would probably lower the compression a tad if nothing else, with all those punch marks.

[David]

I read article, in Popular Mechanics I think, about a guy in India that was putting large notches inside the combustion chamber and insisted he was getting significant mileage improvements. He coulding get any manufaturers to test it.

[sammyg2]

LOL that reminds me of the post where the guy poured BBs down the intake of his japanese engine. Someone told him it would de-carbonize the engine. They weren't kidding, but it also trashed everything inside.
Unrelated but still funny.

[ChrisBennet]

Originally posted by sammyg2
LOL that reminds me of the post where the guy poured BBs down the intake of his japanese engine. Someone told him it would de-carbonize the engine. They weren't kidding, but it also trashed everything inside.
Unrelated but still funny.

That was a Miata engine and the BB's accidently got in the motor not on purpose.
-Chris

[JohnJL]

Pics of the Miata are necessary ;-)

[sammyg2]

Oops. I remember they were in there, and I remember someone saying that was a way to de-carbonize the engine, I must have confused someone's smart a$$ remark with the actual details. I have CRS after all.
It was a very funny thread tho.

[sammyg2]

I found it, here's the carnage:
http://www.miata.net/apple/0111.html

[Steve@Rennsport]

Dimpling, in this context, is used to promote mixture swirl and used in the "lazy" combustion chambers & piston crowns found in hemispherical chambers.

Once still sees it being used inside very highly developed engines such as Nextel Cup NASCAR powerplants.

[snowman]

Dimpling, otherwise called Ribblets. Rilbbets were used on Americas Cup to help win the race. 3 M developed the film that was applied to the bottom of the boat. VERY secret kind of stuff, highly mathematical and very promising if done correctly. Sharks utilize this to help the fluid dynamics of their skins. Yes NASCAR tries to utilize it in their head and intake designs. Would REALLY love to know what is working and what isn't.

Nothing to do with compression, at all, nada. But fluid dynamics and stuffing more charge into the cylinder, a way big thing. Maybe as much as 25% MORE CHARGE ie POWER. I have seen as much as 5% improvement with kids just messing around, porting and divoting without knowledge. Given some KNOWLEDGE and the right kind of divots, just like a golf ball, huge improvements can be had. Unfortunately the "correct" skin might be more like the grooves in a record. They would, unfortunately, get colgged up right away. But who knows, maybe there is a compromise that will do some good.

Unfortunately only world class mathmaticians can even understand the basics of this technology, by world class, I mean something like 5 or 6 out of the entire world, maybe less.

Judging by the past responses to my statement that the engine is a PULSED system, more like less.If you understand stepped and corregated waveguide, and are very very comfortable with all its design aspects, you just might be able to tackle this problem. I mean Greens theorm, Maxwells equations and Shrodingers wave equations, mixed with Fourier series are just like ohms law, simple, straight forward two year old math, a love of cars and engines, and the willingness to dedicate 5 or 10 years to the solution of this problem.

[dimps8]

Snowman..ribblets ha! we had the winged keel.

[snowman]

Who are you guys anyway? I thought the world ended at the equater. Winged keel,,, ha!

Can't win them all can we, good going, but NEXT time....

[JohnJL]

Awesome. My favorite part is the bbs still embedded in the head..sweet...