Foxy said:The length some people got to head flow test anything?
marinatlas said:Hi, it appears that the coriolis effect have in fact no effect whatever the hemisphere regarding the flow in your drain .....it's a tale.
marinatlas said:Hi, it appears that the coriolis effect have in fact no effect whatever the hemisphere regarding the flow in your drain .....it's a tale.
Bernhard said:It didn’t take long for others to turn this page into toilet humour, did it :!:
Bernhard said:Putting that aside, it is well know that the water drains down a plughole in opposite directions depending on whether you are in the northern or southern hemisphere, and neutral at the equator.
Bernhard said:It would be of some interest if anyone this side of the moon had found if it has any beneficial or adverse, or even neutral effect on the gas flow in the inlet ports depending on whether you have a swirl effect on the inlet port right, or left hand and you are in the opposite part of the world :?:
I'm A Tech Inspector For Two Racing Associations. Heres The Scenario. End Of Season, Big Money Race, Using Spec Engines. One Car Is Obviousy Faster Than Everyone Else, While All Year He Was Slow. Upon Inspection It Is Revealed That The Entire Floor And Walls Of The Intake Are Dimpled, Much Like A Golfball. We Confiscated The Intake, Ran Back To Back Tests On Two Different Engines On Superflow Dyno Swapping Intakes Between Tests. Exact Same Intake, One Dimpled, One Not. Both Intakes Port Matched To The Heads. On These Two Engines The Dimpled Intake Made 23.9 And 23.2 Hp More. All Else Being Equal. Take It For What Its Worth. This Was Performed On Engines In The 650 Hp Range.
> Yes, golfball dimples on your intake do make a difference. The main
> improvement comes when they are on the short side radious of the intake
> ports. I have this on my Datsun Roadster head. It works the same as on a
> golball but it takes A BUNCH of time and careful work with a diegrinder to
> get a good patern. It was a couple hours a port to do a perfect job.
> That is funny that you would know about dimpleing ports. Do you race?
> Nolan
Bernhard said:It didn’t take long for others to turn this page into toilet humour, did it :!:
Putting that aside, it is well know that the water drains down a plughole in opposite directions depending on whether you are in the northern or southern hemisphere, and neutral at the equator.
It would be of some interest if anyone this side of the moon had found if it has any beneficial or adverse, or even neutral effect on the gas flow in the inlet ports depending on whether you have a swirl effect on the inlet port right, or left hand and you are in the opposite part of the world :?:
Foxy said:Heres a pic of a golf ball port job done, supposedly creates a laminar flow. Wondering Jim if you ever had a tinker with this concept?
Foxy said:Heres a pic of a golf ball port job done, supposedly creates a laminar flow. Wondering Jim if you ever had a tinker with this concept?
hobot said:hobot is not a proper name that deserves any capitalization.
hobot said:I'm just a pilot so dependent on real builders to advance Commando "style" engines. My hobby project is to put down smug leaning elites in a hurry and not lost ground in the opens. Racing has a lot to do with cheating w/o getting caught.
hobot said:The few articles I've read on this texture stuff implies its only detectable in the already maxed out engines and the more maxed out the more these little things add up. When it happened to me on 2 stroke outboard and Ms Peel, it was a dramatic surprise improvement.
Interesting stuff (flow & fuel dispersion) but I am asking myself why the dimples in intake ports is not prevalent in internal combustion motors (race or otherwise)? Besides the extra machining required, I am wondering (out loud) if there are some performance drawbacks to dimpling.Hm, rational comment, keep that self med going eh. I've studied this enough now to make some sense out the principles and where it might apply but its a chaotic situation that only trial and error can show if worth it or not. The basic trade off is the drag of the roughness/dimples/cross hatching or the projections, lips, groove vs the extra streamlining or fuel re-energizing.
Aircraft and cars use yard strips to see where and when eddies occur. I get to see this on my Gravel travel dusting leading and trailing surfaces. All's I can think to indicate flow, collisions and eddies inside head is spray paint or powder after a spray of wd/40?
Fuel droplets mass throws them to outer radius of bend or blasts them into chamber surface and rising piston crown. This is where dimples and cross hatching has helped get fuel back in flow. I think Norton intake blasts mostly strikes between the exhaust valve then bounces off to strike between the exhaust valve and plug. It would be better if blast hit the exhaust valve more.
Its about a thumb print area that gets my attention to mess up some how.
Maybe a patch of dimples or linear grooves cross wise to flow would stumble the the blast bounce off to let more of the blast flush over the hot valve. ???
I don't think this would interfere with basic swirl induced by our off set two valves. Swirl lasts longer than tumble as compression thickens mixture to almost honey like.
Here's what I think might apply to guide post, a shallow groove on one side or both depending which side of the guide might help the blast sweep into the chamber. Symmetric don't always apply in asymmetric paths, but mixture is flowing past both sides, so nothing for it but trial error measuring.
http://www.princeton.edu/~asmits/Bicycl ... mbined.GIF
I'd want to try spiral rifling like ridges in the manifold bend, as Victor
Viktor Schauberger did to run too big of logs in too little of water in log chutes. He got into vortex areo dynamics too with some of the Nazi saucer ships
I'd try a downward offset of the manifold to head for .05-06"-ish trip up lip.
A rough expedient gasket intruding was part of past Peels accidental spunk to flat run out form under if not locked in first. Another was standard 28-ish mm head that may of worked even better if shaved for 10-ish CR. If I ever put past Peel's combo together again I will for sure try it before and after a shaving to get sense of the CR effect in a mere factory Combat.
I'm holding out for a set of Antelope headers