AG burr finish
Here is what I used to port and then finish. The burr in the grinder is bent about .125 and it is a gradual bend starting about 2 inches from the grinder end of the burr. Other two aren’t bent.
To get that finish I bent up over the years probably 20 burrs. Some of them I still have. May have to go through them and maybe take some of the bend out and see how they work.
Once you get a burr that is bent that you feel comfortable with, you control the finish with burr speed and pressure. You have to let the burr chatter off the port, but it can’t be so bouncy it will rattle your teeth out. And I found that I need the burr a little faster than it probably should be turning, and then use pressure to control the burr.
I wrecked a bunch of burrs and ports learning this to the point I feel comfortable selling it. Wish we could do an A-B-A test to back this finish up, but I’m pretty sure I have it damn close. At least I hope for Scody21 it is. This stuff is his...so...it’s either the pent house of the out house for me. I have no in between.
The biggest thing is just to GENTLY bend a burr and measure the runout and then go test it. Use burr speed and pressure to get the finish you want.
I do know that Larry Meaux (if you don’t know who he is look him up and read anything g you can that he writes if you are into this stuff) said he has yet to find a finish too rough. Chad Speier will not do an intake manifold without a burr finish. Speier says he has went to the track with a customer, made some passes, pulled the intake right there, burred it up and put it right back on and the car was quicker. How much I forget, but it wasn’t some .001 number.
Both of those guys have reputations for making power and setting records. In fact, Darin Morgan (again, if someone doesn’t know who he is, look him up...and I just posted a link to a webinar he gave Wednesday in the racers forum) says they have been using the burr finish since the 80’s and when you have 3 guys with records like that, I have to give it a shot.
In fact, Darin says he uses a burr finish on EFI systems. It’s in the webinar, so if you want to know what exactly he said I posted the link.
Here is what I used to port and then finish. The burr in the grinder is bent about .125 and it is a gradual bend starting about 2 inches from the grinder end of the burr. Other two aren’t bent.
To get that finish I bent up over the years probably 20 burrs. Some of them I still have. May have to go through them and maybe take some of the bend out and see how they work.
Once you get a burr that is bent that you feel comfortable with, you control the finish with burr speed and pressure. You have to let the burr chatter off the port, but it can’t be so bouncy it will rattle your teeth out. And I found that I need the burr a little faster than it probably should be turning, and then use pressure to control the burr.
I wrecked a bunch of burrs and ports learning this to the point I feel comfortable selling it. Wish we could do an A-B-A test to back this finish up, but I’m pretty sure I have it damn close. At least I hope for Scody21 it is. This stuff is his...so...it’s either the pent house of the out house for me. I have no in between.
The biggest thing is just to GENTLY bend a burr and measure the runout and then go test it. Use burr speed and pressure to get the finish you want.
I do know that Larry Meaux (if you don’t know who he is look him up and read anything g you can that he writes if you are into this stuff) said he has yet to find a finish too rough. Chad Speier will not do an intake manifold without a burr finish. Speier says he has went to the track with a customer, made some passes, pulled the intake right there, burred it up and put it right back on and the car was quicker. How much I forget, but it wasn’t some .001 number.
Both of those guys have reputations for making power and setting records. In fact, Darin Morgan (again, if someone doesn’t know who he is, look him up...and I just posted a link to a webinar he gave Wednesday in the racers forum) says they have been using the burr finish since the 80’s and when you have 3 guys with records like that, I have to give it a shot.
In fact, Darin says he uses a burr finish on EFI systems. It’s in the webinar, so if you want to know what exactly he said I posted the link.
