Incase you guys are thinking of either AFR, or TFS heads in the 195cc range. Here you go........


I am building a 421, and have decided to go with a head that offers wicked port velocity. These are my findings! I am going with the Comp ports!



Trickflow-195cc, 62cc, 2.02/1.60

Intake

.200 138 cfm
.300 190 cfm
.400 230 cfm
.500 253 cfm
.600 260 cfm

Exhaust

.200 98 cfm
.300 130 cfm
.400 156 cfm
.500 174 cfm
.600 188 cfm



Street Ports. AFR-195cc, 65cc, 2.05/1.60

Intake

.200 143 cfm
.300 199 cfm
.400 246 cfm
.500 276 cfm
.600 286 cfm

Exhaust

.200 113 cfm
.300 161 cfm
.400 195 cfm
.500 214 cfm
.600 218 cfm



Competition Ports. AFR-196cc, 65cc, 2.08/1.60

Intake

.200 153 cfm
.300 210 cfm
.400 257 cfm
.500 287 cfm
.600 303 cfm (wow!)

Exhaust

.200 124 cfm
.300 170 cfm
.400 205 cfm
.500 227 cfm
.600 235 cfm (wow!)

 

Thank you for the post and adding the information. It will be good for those doing research. Your flow numbers on the AFR Comp heads are virtually identical to mine so they are not a fluke.

Trickflow is falling behind but I guess the price will still keep them in business. They are not a bad head but certainly not among the top heads anymore.

 

Your more then welcome.

The Trickflow's are the newer Kenny D's. They are simply outclassed by the AFR's. However in saying that, 2-3 years ago, 260cfm was notbad!

I orginally was going to install the TFS heads on my 383, but I changed my mind and went with a 421. The TFS would of performed poorly on the big stroke hence the changing heads.

Alot of guys think the 196 cc AFR are too small for a 421! It's about port velocity.

 

Bump to the top for the guys who missed the flow #'s.

 

depends on your rpm range i still think a 421 should use the comp 210's for anything over 6K rpm.

Trickflows last time i've heard are around same price as street AFR's. I like the AFR's for their valvetrain components. Good stiff but light small diameter springs and 8mm hollow valves. LS1 technology in a small block head

 

We know the motor would make more power with the 210 comp ports, but I think you will be suprised when all the dust settles in regards to top end power!

If I wanted maximum horsepower. I would go bigger then the 210's.

 

Yeah there are a few vette guys over at the vette forum i'm interested in seeing how their builds turn out. A few 420-421 inchers that should make some nice power but they all are using heads i'd feel are too small. I'd use the 210's even if i wasnt going for max hp but thats just me. 195's to me are like using 180's on a 383. IT can be done but you give up alittle to alot, depending on the combo

 

It's all about driveability for me. I want a car that is going to have crazy throttle response and this will have exactly that. It will have power from idle right to redline.

I know what you getting at, and I know if I wanted to reach the 600chp area, it wouldnt be an issue, but that's not the goal here. I know you have mentioned it time, and time again that my heads are too small, and you might be right for someone trying to max out the combo.

LPE used to run a combo like this.......

-Bowtie block
-236/244, .549/.549 110 lobe
-ported 190 AFR's
-ported superram
-11.1 CR

That combo made 525/543 at the crank, and the driveability was excellent and it got good gas mileage. My car is an all purpose car for now. It will be used to drive to the grocery store, as well as a 500 mile road trip. In the future if I decide to buy a C6 it will remain stock, and if that time comes then I will go hog wild and make some big power.

My combo should make a little more hp then the combo listed above with the miniram, and 11.6 CR.

"The combination of the large displacement, smallish heads, high lift roller cam, and the intake system make big block torque in a small block package".

In a nut shell, that is what I want.

 

But none of them are going to use an exhaust termination box. Then again there may not be much to gain. We will find out.

 

I'm afraid its gonna be TOO responsive and just blow the tires off with any quick throttle input. That gets old not being able to hook up


I'm gonna work on mine. I'm joining both of my headers into a little circular box which has little impellers inside of it that spin very fast. I hope it adds some hp.

 

I understand those impellars in the exhaust can add quite abit of horsepower. Quite unlike that company that was selling them on the intake side. Hahahaha.

 

It won't be too responsive man! And I highly doubt it will get old quick.

Count me out for the impellars.