This is I think my 5th or 6th port I have done. I have a bunch of extra irons laying around ready to be scrapped. Some of them I ended up getting a little too relaxed and the bur jumped out so this time I took my time and jammed out to some godsmack and this is what I ended up with. Please give honest opinions.

Thanks


Edit: I should mention that the scuff marks are from the sanding drums.


http://i157.photobucket.com/albums/t...k/DSCN0487.jpg

http://i157.photobucket.com/albums/t...k/DSCN0488.jpg

http://i157.photobucket.com/albums/t...k/DSCN0489.jpg

http://i157.photobucket.com/albums/t...k/DSCN0490.jpg

http://i157.photobucket.com/albums/t...k/DSCN0491.jpg

http://i157.photobucket.com/albums/t...k/DSCN0492.jpg

http://i157.photobucket.com/albums/t...k/DSCN0493.jpg

 

wow...ummmm, how much material is left between the port and the coolant jacket??

it has to be paper thin

 

well, your work looks a lot like mine used to back in the day. i don't mean that as condescending as it may sound, i'm merely saying that it's clear to see that you're not seasoned yet. now, i don't (and would NEVER) compare to Judge Ito or BDC or Kahren or any of the people i consider to be my idols, but i have come a long way.

tips ...

now keep in mind, this is my opinion and you'll probably develop your own preferences in time. however, i think you need to focus on shaping the upper part of the opening edge a bit. you could also shape the closing end a bit more. which template are you using? i also think you could open up the runner a bit more. make sure to keep a venturi on the runner - meaning it will get narrower as the mixture heads to the bowl.

i wasn't able to see texture, but finish the bowl a little rough for atomization. i use 120 now, where i used to use 220.

 

It is a RB port, and I stop at 120 as I dont have a 220 flapper wheel. Also with alot of people saying that they dont use sandpaper, or they use 220 flap wheel (as per the MazdaTrix video) I figured I would just "meet in the middle" so to speak. For the runner, I simply "smoothed out" the edge that was there and ramped it in a bit easier.

As far as the water jacket, it feels pretty thick still. It appears that with the RB template on a 12A iron, it seems you can damn near go straight down and barely punch through. Not sure how it would be on a 13B though.

Thanks for the tips guys and keep 'em coming.

 

The reason why people don't sand there ports to a mirror smooth finish is because it creates more drag than it helps.

Think about a golf ball

 

Bigger isn't better. Port to remove pressure drop points; things that will slow charge velocity (make the air go slower). When you enlarge, it drops velocity and shifts the powerband way up. When you focus on closing edge, it slows velocity and moves the powerband up. Focus on opening edge and not going big.

Making powers comes from velocity; not size.

B

 

well, i understand why that applies to N/A engines, but for forced induction, doesn't size matter to an extent? i realize that it may not apply to IanS's build, but generally speaking ...

 

NO... It's a little "more" important on N/A but it DOES matter for forced induction as well. You STILL have an opnening and you STILL have a closing. The thing that really makes a big differance on N/A is making sure your exhaust and intake "work" with your port.

-J

 

So just so I can get this straight. You guys are saying that I should have ground at a lower angle when making the port? For example if I was going for a 60 degree angle, I should have aimed closer to a 45? The hard thing about that is the original port was higher of an angle than 60 to start with (the ramp at the bottom). I honestly thought I was making a better transition than was there originally.

I understand the "bigger isnt always better" thing, but at the same time isnt that why people port their engines? To get more air in and out of the engine as fast as possible.

My end result will be RB primaries, Ito secondaries and I already have the RB race exhaust port done. Also I will be running my Sterling NIKKI carb with mechanical secondaries, RB road race exhaust, etc, etc.

Edit: Please explain more in detail how to shape the closing edge more. It goes straight down stock and I dont really remove anything from that area. How can I change the shape??? I understand the opening edge. That needs to be thinner and a smoother rounder edge.