blown 540 heads?

[Flatblack 57]

Gday, need new heads for new 540, 871 blown. Thinking AFR 375, cnc. Have not picked cam yet, but will be flat solid. Street and strip duties and 98 oct fuel. Is bigger better on a blown motor?

[pat mccarthy]

the cam i would run would be a roller solid or hyd i like to build them with hyd roller cams but for my engines i like the soild rollers you do not need a big cam with a blower it get push in but i have a 548 that i run a 714/714 in the @ .050 268 /272 lc 110 i am verry happy with the way this all works on my blown 548 this cam or close to it on may be on 114 lc may work better for you you? did not say how much CR you have. i have 10to1 off the bat so i like the 110 but there could be better cams for you that just what i know works for me .if you go hyd roller you need spring pressure to hold the valve shut the hyd lifters are very heavy if you go this way run a rev kit on the hyd lifters

[Flatblack 57]

What about the head choice Pat. To big or just right. Comp will be 8.4. I still don't know about rollers for the street. I want as low maintenance as possible. Don't want to change lifters every 10k. And i admit i know little of hyd rollers. I have had good luck with flat tappet solids in the past. What also puzzles me is how a heads runner size and flow can alter torque and hp levels. Smaller ports will give better torque, but less hp? Whats that about. And how do you apply this to a blown motor.

[pat mccarthy]

well if you go soild flat you should go with the EDM holes thru the lifters so you get added oil .if you going to put more miles 3000 a year? if so you may want to re think your build and a soild roller or hyd roller is the only way to go .by far better then you soild flat cam.. the soild rollers i would say you will never get 3000 miles out of springs or lifters even the hyd roller you better be looking at your valve train more then that . i think the heads may be abit to big .i did post on the same stuff for you back in the spring?