I just want to thank Jeff for taking care of us on these heads.

As you can see they look really really good, and should make some good power.









Here is the intake side with the flash light shining in it.


Another one without the light.


Here is the exhaust side.





I do have a question for everyone, the machine marks the CNC machine marks left in the ports, would you remove them or not? Jeff said they have removed them and found no HP gain?

What would you do?

Would you just removed the marks on the exhaust side? single choice
	Yes
Votes accepted starting: 11/21/09 07:51 PM You must vote before you can view the results of this poll.

Would you remove the machine marks on both the intake and exhaust? single choice
	Yes
Votes accepted starting: 11/21/09 07:51 PM You must vote before you can view the results of this poll.

Would you just leave them alone? single choice
	Yes
Votes accepted starting: 11/21/09 07:51 PM You must vote before you can view the results of this poll.

Modern Cylinder Head always does beautiful work, i have no complaints at all, he did a great job on my hemi heads and would use him again.

I agree, and the only reason I asked was I have a friend that builds several SB2 off brand engines, and the heads are Nascar stuff and both the intake and exhaust are smooth as a baby's butt?

i've heard smoother isn't always better on intake side,but i'm only runnin 10.70s with stock eddys.

you want the smoothest surface which enables you to create the thinnest boundary layer

most nascar/prostock stuff has a nc'd int port, polished chamber and exh port,,, we never seen anything in polishing

Hate to Highjack the post, but quick question for Jeff, Stage V CNC with qaulity valvetrain compared to B-1 CNC qaulity valvetrain, which set-up seems to produce more HP and Torque on comparable bottom ends, and cost difference in the end, my thought is they would most likely end up with similiar cost and performance numbers, or am I out in left field.

what castings are those? Lets see some flow data

From my fluid mechanics classes in college many years ago, the air velocity right at the wall is zero (infinite shear stress would be required to have some velocity there), so I would think there is so little flow that close to the wall (within .010") that it wouldn't make much if any difference. Maybe they polish them to make them easier to clean and rebuild after each race?

Lets look at the surface of a golf ball, and under stand why it travels so far with so little resistance.

Very interesting topic guys.

Fred that does sound very logical.

And I assume that's for the exhaust as well, leave them both alone, right.

Bob here is my flow sheet, not as good as yours, but should make go power. I will be posting up more of our combo later to see what yall suggest for a cam for this little engine.

you dont want a polished surface at all for a car engine.
the surface roughness should be such that it slightly disrupts the boundry layer of material(gas/air)flowing over it.
the viscosity of said mixture needs some turblance to properly swirl down the ports and around the turns at an equal velocity. cause air mixture passing a bend creats a differential pressure at bends and would reak havoc exiting the turn if the boundry layer was too smooth.
think skidding on a turn when driving too fast especially when smooth surface-well kinda.
fluid dynamics is a simple principal propetry of all things that flow.
the golf ball and even your hood scoop height above the boundry layer and examples.
also too smooth and condensation may form and submilate out liquid gas too rich and drip.
its all about press/temp/delta press/viscosity/surface finish(Ra.)

You trusted Jeff with your valuable heads. Why second-guess his advice?

Ain't touching them Fred.

I agree moeflo, he said they had done it just didn't see any gains on the ones they did.

Just thought it was good discussion.

I have learned a lot and hope others have as well.

Jeff, what can i do to get my hemi heads to look like this?

My name is Jeff also, but just call Jeff at Modern and he will fix you up.

What casting are those? As of now I plan to run a flat tappet cam, so those big numbers dont matter much...

Looks nice Jeff..keep us informed on your progress please
What have you decided to go about motor wise? Cubic Inch? Compression? Cam etc?