Question on Heads

[Chalrie57]

I am working on a 383 I have been told to get 180 heads and I have been told to get the 200 heads. What I have learned is the 180 will be more responsive at the low end but I will loose some top end power. The 200 will be a little less responsive but have plenty at the top end. I have been looking at the Brodix IK180 and their IK200.
Now I have seen the AFR 180 heads which cost about $300 more but flow better then the Brodix 200. From what I have learned it sounds like the AFR would be a good match if I was willing to pay the extra money. So would I keep my low end response and my high end power?

Charlie

 

[grumpyvette]

yes youll gain a bit more with the AFR 180s over the BRODIX IK but those heads cost more as youve pointed out,and the AFR 180cc are an excellent choice if your main goal is a responsive street engine combo, personally ID suggest the 195 eliminators on a street 383 but theres not much wrong with the 180cc either , THE CHOICE OF PORT SIZE SHOULD BE MADE BASED MORE ON THE INTAKE AND CAM TIMING THEY ARE MATCHED TOO! AND THE INTENDED USE OF THE ENGINE, remember the goal is matching effective cylinder fill rates with the intended power and rpm range of the engines head flow, and heads only flow in combination with the intake and cam timing, and displacement and compression ratio and the cars gearing will effect those choices
ok, assuming your static compression ratio matched to your cam timing drops your dynamic compression into the 7.5:1-8.5:1 range for pump gas octane,and your running a stall speed on your converter that matches your cams power range or a manual transmission and most of your combo matches the following guide line might help

if the cam you sellect for that 383 has less than about 230 dur at .050 lift, and if your rear gearing is in the 2.87-3.36 range and your useing a dual plane intake the 180cc will work ok, but if the cam has about 230 or more duration (AND ESPECIALLY WITH A SINGLE PLANE INTAKE) and your rear gearratio falls in the 3.54:1-4.11:1 range ,the slightly larger 195cc heads going to be a better selection, if the cam duration falls in the 245 plus range, a single plane intake and a 4.11:1 or higher rear gear ratio and the 210cc heads will be better in most cases

why not read thru these
http://www.airflowresearch.com/super-chevy-apr-2010-210cc-sbc.php

viewtopic.php?f=52&t=333

viewtopic.php?f=52&t=1070

viewtopic.php?f=38&t=1099&p=2152&hilit=volumetric#p2152

http://airflowresearch.com/articles/article074/A-P1.htm

http://airflowresearch.com/articles/article085/A-P1.htm

http://airflowresearch.com/articles/article031/A-P1.htm

viewtopic.php?f=52&t=796

viewtopic.php?f=50&t=1482&p=3509&hilit=volumetric#p3509