Builders....who never rolls their personal heads/intakes

[Walter R. Malik]

Personally ... I like a cuttered finish on the intake and a 60 grit on the exhaust but, the main thing is that the finish be consistent throughout.

Being consistent usually won't really matter about how it works but, racers are romantic about their parts.
It just gets more attention for being good to those who really don't know but, it is their own decision about where they spend their money.

Some porters just NEED to use a cartridge roll finish in order to make their port walls flat.

[roc]

0603170952.jpg

Horrible right? I use this poor thing for 90% of my finish work. It is old, beat, bent, but with the right speed is smooth and leaves the finish I prefer. It took lots of hours roughing ports at higher speed to get this burr just right. 1/2" oval, 6" shaft. Thanks, Charlie

Charlie, thanks a for sharing this info. Is this for iron heads only? Or aluminum? Or both?

[Carnut1]

0603170952.jpg

Horrible right? I use this poor thing for 90% of my finish work. It is old, beat, bent, but with the right speed is smooth and leaves the finish I prefer. It took lots of hours roughing ports at higher speed to get this burr just right. 1/2" oval, 6" shaft. Thanks, Charlie

Charlie, thanks a for sharing this info. Is this for iron heads only? Or aluminum? Or both?

I usually use this burr for iron but it does just as well with aluminum. I use wd40 to keep the burr from being plugged. Many of my aluminum heads I finish with a single cut burr that leaves a rougher surface than this double cut beater.

[user-9274568]

The reason burr finished DOESN'T work in a manifold is because some guys charge $2000 to port a manifold.

End of story, goodnight.

[Carnut1]

For $2 k I would waste quite a few hours making it pretty!

[roc]

0603170952.jpg

Horrible right? I use this poor thing for 90% of my finish work. It is old, beat, bent, but with the right speed is smooth and leaves the finish I prefer. It took lots of hours roughing ports at higher speed to get this burr just right. 1/2" oval, 6" shaft. Thanks, Charlie

Charlie, thanks a for sharing this info. Is this for iron heads only? Or aluminum? Or both?

I usually use this burr for iron but it does just as well with aluminum. I use wd40 to keep the burr from being plugged. Many of my aluminum heads I finish with a single cut burr that leaves a rougher surface than this double cut beater.

Thanks again Charlie.

[Carnut1]

Happy to help. If it actually helps anyone.

[roc]

Happy to help. If it actually helps anyone.

[pamotorman]

my ported heads and intakes were done by katech and starting back in the 70s the intake ports were finished with I would say a 60 grit finish.

[GARY C]

It's easier for me to visually equalize ports and the contrast between paper roll over the shiny cutter surface helps that.

[Carnut1]

It is application specific. I have been able to convince most of my customers, that the carbide finish on the intake is what you want, and I still sand/finish chambers and ex ports. That's what they will accept. To do a proper carbide finish, it still takes time. If its a high end head, I will sand, to straighten and blend, then re-carbide. Even if I use no sanding rolls, I still spend time straightening/blending with a finer carbide. The only thing it really saves, is cartridge rolls, and the mess/grit/dust. To do it right, is still time consuming. It can be done in a "lazy" fashion to save time, which by the looks of some of it, that's whats going on, and if it is, I wonder if they are charging any less.

Its funny how the internet works. I have been doing this stuff since the early to mid 90's. Dimpling chambers, rough carbide intake finishes, etc, and, my finish work is as good as anyone, and better than most. The person I got the concept from was Jim Mcfarland, a true tech writer that is a real engineer, with a doctorit in mechanical engineering. Wonder what ever happened to him. Funny how 1 guy, copies another guy, but then takes/gets all the credit, gotta love the internet. We have also done similar back to backs on the dyno, leaving engines on, pulling heads, etc, also with valve seats. Radius vs multi angles, numerous times. Do the radius valve job first, then use a single angle blade, 60 degrees, cut the radius away till it "catches up" with the seat and stop, then using a 75 below that. One test we pulled the heads and re-cut the 60 into a 65, and re tested. Angles work better, period. Its not earth shattering, but its something for sure. The engine will make better power with less fuel, and or more power with the same amount of fuel, always a plus.

For my own heads, I never sand. Unless I plan to sell the engine. Then I will do the ex ports and chambers. Just because someone else will likely see it at some point, and I don't want to hear, he does shitty work.

Shaft, I have done the angles vs. radius valve job on the intake and seem to get better flow numbers on the intake. On the Dart 215's I am still working on they come with a radius exhaust valve job. Do you still find gains changing to angles on the exhaust? My exhaust port is a bit lame at 78cc and only 227 cfm @ .7" lift. Thanks, Charlie

[MadBill]

I believe the consensus is that a radius on the exhaust seat helps flow and power, but that on the intake it helps flow but hurts power, due to fuel shear issues.

[blown265]

Bill,
With a dry fuel like Propane, would the radius be advantageous on both seats? (exhaust AND intake)
Thanks
Paul

[MadBill]

I expect so.
It would also be interesting to compare wet flow-optimized heads on dry vs. wet fuel to verify if their presumed gains were 100% due to fuel control vs. air management.

[modok]

Even a dry fuel....it is still beneficial to be thoroughly mixed and "stirred up" before the spark plug fires. I'd worry less about runners, but the bowl, and valve seat, still going to be important in getting a good burn.

Had a guy complain today that there were some small streaks of hard carbon deposit in the ports in a few spots.
just have to smile and nod.
If that was mine I'd have left a lot MORE carbon in there, filling in those dead spots. It's just going to run worse to "clean" it out.