Rember the intake port texture debates?

[MadBill]

... When I apply Bernoulli’s principle it would seem that the dimpling would create a higher pressure (due to the higher velocity air within each dimple) which, I would think, would repel “wetting” of the port walls.

Per Bernoulli, higher air velocity is accompanied by lower pressure..

[KnightEngines]

Must warn you, when I'm done with all 8 ports my hands and arms are tingling. It's a little weird..

Be carefull Chad, that's a sign you're doing nerve damage - google 'white finger' & reynauds syndrome.
I got it, it ain't fun, the last 2 fingers of my left hand go white & dead if they get too cold - & the amount of cold required has gotten less.
Once they go dead you gotta stop & warm them up pronto, no blood flow for extended periods = dead flesh.

Wear gloves - I use 'carpenters' gloves with 2 fingers missing so I can still feel stuff. also get yourself a gel cover for your grinder.

[Carnut1]

Must warn you, when I'm done with all 8 ports my hands and arms are tingling. It's a little weird..

Be carefull Chad, that's a sign you're doing nerve damage - google 'white finger' & reynauds syndrome.
I got it, it ain't fun, the last 2 fingers of my left hand go white & dead if they get too cold - & the amount of cold required has gotten less.
Once they go dead you gotta stop & warm them up pronto, no blood flow for extended periods = dead flesh.

Wear gloves - I use 'carpenters' gloves with 2 fingers missing so I can still feel stuff. also get yourself a gel cover for your grinder.

100% correct, one of the reasons I prefer the monster grinders is they absorb much of the vibration. Holding grinders tight and vibrating cause poor circulation. Temp is a factor, one of the reasons I now live in hell. At least my hands don't go numb at 50 degrees anymore. Be sure to take breaks to get the circulation back! Often.

[GARY C]

I remember grinding with air in the winter and having to wrap the die grinder with a rag so it wouldn't blow frozen condensation in my face and freeze my hands to the grinder.

[Carnut1]

0613172037_2.jpg

Close up, back lit DV. E7TE exhaust port finish. Enlarged to show texture, just like a cereral box. Hairs are from the paper towel I used to give it a quick clean. Thanks, Charlie

[nickpohlaandp]

... When I apply Bernoulli’s principle it would seem that the dimpling would create a higher pressure (due to the higher velocity air within each dimple) which, I would think, would repel “wetting” of the port walls.

Per Bernoulli, higher air velocity is accompanied by lower pressure..

You are correct sir. I was typing faster than I was thinking. I will happily don my dunce cap and go sit in the corner. I used to fly planes, that's a stupid mistake to make, and now it's on the internet forever, lol

[nickpohlaandp]

0613172037_2.jpg

Close up, back lit DV. E7TE exhaust port finish. Enlarged to show texture, just like a cereral box. Hairs are from the paper towel I used to give it a quick clean. Thanks, Charlie

Ummm... I've never seen a guide ground down like that. Please explain.

[Carnut1]

0613172037_2.jpg

Close up, back lit DV. E7TE exhaust port finish. Enlarged to show texture, just like a cereral box. Hairs are from the paper towel I used to give it a quick clean. Thanks, Charlie

Ummm... I've never seen a guide ground down like that. Please explain.

Take a look at DV's E7TE thread and then google a stock E7TE exhaust port picture. That will give you the back story and what the port started at. First off the ports are tiny 120cc intake and 43cc exhaust more or less. The casting is thick in spots and not so thick in others but can be made to work with careful sonic mapping. These will always be cc limited. I think the intakes are 153cc and exhausts about 50cc off the top of my head. Why is the guide cut like that? Area, or the lack of it to turn the air. I would love to raise these ports .2" or so but on some complex curves the sonic just will not read and I have too many hours in these to push my luck. Thanks, Charlie

[MadBill]

... When I apply Bernoulli’s principle it would seem that the dimpling would create a higher pressure (due to the higher velocity air within each dimple) which, I would think, would repel “wetting” of the port walls.

Per Bernoulli, higher air velocity is accompanied by lower pressure..

You are correct sir. I was typing faster than I was thinking. I will happily don my dunce cap and go sit in the corner. I used to fly planes, that's a stupid mistake to make, and now it's on the internet forever, lol

Yeah, wouldn't it be great if the 'Edit' button stayed live for longer?

[statsystems]

... When I apply Bernoulli’s principle it would seem that the dimpling would create a higher pressure (due to the higher velocity air within each dimple) which, I would think, would repel “wetting” of the port walls.

Per Bernoulli, higher air velocity is accompanied by lower pressure..

You are correct sir. I was typing faster than I was thinking. I will happily don my dunce cap and go sit in the corner. I used to fly planes, that's a stupid mistake to make, and now it's on the internet forever, lol

Don't feel bad. It's hard to get over on Mad Bill, Kevin Johnson, Stan Weiss and those guys.

They don't miss much.

[na svt]

Does this work better with a carburetor or EFI? Dry air or "wet" air? Or does it not matter?

In the head, all intake ports will be wet unless they are direct injected.

[racear2865]

Must warn you, when I'm done with all 8 ports my hands and arms are tingling. It's a little weird..

Be carefull Chad, that's a sign you're doing nerve damage - google 'white finger' & reynauds syndrome.
I got it, it ain't fun, the last 2 fingers of my left hand go white & dead if they get too cold - & the amount of cold required has gotten less.
Once they go dead you gotta stop & warm them up pronto, no blood flow for extended periods = dead flesh.

Wear gloves - I use 'carpenters' gloves with 2 fingers missing so I can still feel stuff. also get yourself a gel cover for your grinder.

You know I must have that too. I can drink a quart of moonshine and I start to tingle then all of a sudden I dont feel nuutin for about 8 hrs. What is that name again so I can ask mt doctor.
reed

[n2xlr8n]

Must warn you, when I'm done with all 8 ports my hands and arms are tingling. It's a little weird..

Be carefull Chad, that's a sign you're doing nerve damage - google 'white finger' & reynauds syndrome.
I got it, it ain't fun, the last 2 fingers of my left hand go white & dead if they get too cold - & the amount of cold required has gotten less.
Once they go dead you gotta stop & warm them up pronto, no blood flow for extended periods = dead flesh.

Wear gloves - I use 'carpenters' gloves with 2 fingers missing so I can still feel stuff. also get yourself a gel cover for your grinder.

Or...carpal tunnel issues. My brother (Ortho SA) said that one could tell where the nerve impingement would be by which fingers were affected. Something along the lines of "thumb + forefinger = wrist, middle to pinky = elbow or shoulder."

I had bilateral CT surgery in 2009- mine was thumbs plus forefingers. Be careful. Gel cover is a great idea.

[Carnut1]

0617171327c.jpg

I would like some feedback on this texture. D.V.'s E7Te heads I am finishing up. Same finish on exhaust, intake and chambers. Why do I use the same finish on all three at this point? I am able to blend my curves pretty well with this size and style, beat up burr. So, I only need to roll my chamber edge and this chamber is done unless I see something that could use more attention. I feel this surface helps atomization a bit on intake, has a slight golf ball surface which reduces airflow resistance. On the chamber can still help atomization by breaking up any liquid fuel that enters chamber, the finish is smooth enough I feel it will not have hot spots that may cause detonation or preignition and has a bit of heat reflecton ability due to the tiny scalops. Exhaust port will get same finish due to slight airflow resistance reduction due to golfball effect and intake and exhaust will get ssr polishing with sandcloth. Input welcome. Thanks, Charlie

[desoto30]

Must warn you, when I'm done with all 8 ports my hands and arms are tingling. It's a little weird..

Be carefull Chad, that's a sign you're doing nerve damage - google 'white finger' & reynauds syndrome.
I got it, it ain't fun, the last 2 fingers of my left hand go white & dead if they get too cold - & the amount of cold required has gotten less.
Once they go dead you gotta stop & warm them up pronto, no blood flow for extended periods = dead flesh.

Wear gloves - I use 'carpenters' gloves with 2 fingers missing so I can still feel stuff. also get yourself a gel cover for your grinder.

X2 Yes...
I also have Reynards, but fortunately live in central Qld.. Where it is much easier to manage as temperatures above 25* seem to cause no issue.. You in SA would without doubt suffer more & for longer each year.. I unfortunately also have Duputytren's which one of the said causes is vibrating tools & a northern [or part] northern European Scandinavian heritage, sometimes referred to as Viking hand, Or Viking disease.

Weird tingling hands are an indicator that is for sure.