Ok, so I am going to put the 406 in my sig in in a few months. I am having second thoughts on using my AFR 190 heads. Of course I believe I will see more performance from 210 cc heads but to what degree? I believe the flow numbers are not too far apart. The 190s are down 5 cfm at .4 inch, 17 cfm at .5 and 22 at .550. Is this a very significant change? With a 20 cc smaller intake I believe torque will be up. What is the max HP potential for the Street port 190 cc heads? Oh, the cam I plan will be about 240 degrees and .570 lift. Thanks

 

If you want more airflow, then get the 190's ported. The general rule is each 2 cfm equals 1-2 hp.

Mine are ported and the intake runners are now 207 cc's instead of the 190.

They flow intake 295 @ .600 and exhaust 235 @ .600.

Just get them ported and they will flow more air. No need to buy another set of heads.

 

Ok, sell I could sell the 190s for say 900 and have 500 to buy 210s. Or I could have the 190s ported for 500. Same boat. Why did you pick a 114 lsa? Is your cam a solid roller? Did you use H beam rods? Also, I am concerned with quality of flow. Not just xxx number. I kinda trust AFR to do me right.

How can 2 cfm = 2 HP?? I have 262 cfm. Is this per cylinder?

 

You would get better flow with the ported 190's than the stock 210's. AFR doesn't hand port, so the cnc machine would do the work. A hand port will beat the cnc machine. The porter will match the heads to what you want to do.

A friend got the 210's with the comp porting package, and then took them to the same place mine were ported and got even more flow out of them. For the price of AFR's comp port package, I wouldn't pay for it versus hand porting. Just my $.02.

My cam is on a 114 for idle, the bottle, and more midrange-top end power than torque. I couldn't hook up with the superram to save my life, so I'm shifting the powerband up. I'm going to shift at 6500. I didn't go with the solid this time. Maybe next time. I wanted to see what the hydraulic with the hydra-rev would do first. I have the 4340 crank and h-beam rods.

The formula is .2527 * cfm * # of cylinders = potential hp based on airflow, assuming everything else being perfect. This is a good site to compare airflow numbers, even though it has LT1 heads on it, same theories apply to all motors.
http://www.malcams.com/legacy/misc/headflow.htm

 

Thanks for the input. Where do you think the stock 190s will put me in the HP department?

 

It all depends what you want to do.

If you want max power, get them ported, milled and keep the quench around .040. Mine is at .038.

Is this a flat tappet cam for the 400, or roller?

I got 493 hp @6000 and 459 tq @ 5000 from my program using the comp cams 240-246 flat tappet cam and 10:1 comp.

What you want out of the car dictates at what level the heads should flow.

 

Smaller port heads tend to have better port velocity in the lower RPMs which will provide more low-end and better throttle response than larger ports, however they obviously cannot flow the numbers the larger port heads do at the high revs. My opinion- stick with the 190s w/ a little pocket porting.

 

Roller!

 

ROFLMAO at worrying about port velocity in a 400 planning to run a 240' @ 0.050 cam.

This is how i'd look at it. Will it run pretty good with AFR 190s, espeically ported. Damn right. Will out of the box AFR 210s outflow the 190s by much, probably not. Will you have the potential to make more power with the 210s down the road though, ABSO-MOTHER****IN-LUTELY. Will you miss low end torque in a 500hp+ motor, no way. Will a built 400 have any trouble maintaining throttle response with the 210s, no way.

AFR 190s are great heads and all...ON A DAILY DRIVEN 350. A 240' @ 0.050 cammed 400 wants and needs a little more air than a street driven 350. If you can swing it $$$ wise, IMO the choice is clear

Keep in mind that selling the used heads will be enough of a loss. You're not going to retrieve the $$$ spent on getting them ported if you decide to sell them down the road. Might as well take the loss and put the port $$$ towards the bigger heads.

 

If you decide to sell your 190's for around $900 in the near future for the bigger AFR's, I'd be the first one to make you an offer. I was going to purchase a set of AFR 190's this week but I didn't get as much money on my loan as I requested. So instead of having an extra $1500 to spend after I pay off a school loan I only have right around $1000. I have the money right now, so let me know what you decide.