Join Date: Nov 2011
Location: Moyock, North Carolina
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Colts stage 1 and 2 cams they say you can get away with not fly cutting the valves.... And there should be gains from that and port work... The engines were designed heavily with emissions in mind. Also you could consider solid roller lifters while you're in there. I have evidence to support the fact that our hydrualic lifters eat up as much as 20-30% of our already abysmal lift and duration. Trouble is you have to be able to adjust them... Enter the harland sharp rocker arms... But here 2500 bucks. If I can get 3-4 people together interested I can get them for about 1700 per set. Theyre shaft mounted adjustable rocker arms... And they're not held together with a plastic clip like stock lol. If I was the head engineer at navistar and someone brought me the 6.0 rocker arms and said... "here it is...all done, ready for production"... I'd say "you're fired... Get out" lol.
The valve angles are 30* intake and 37.5* exhaust... 6.4's have the same size intake valves but the angle on their itakes is 37.5*. The 6.4 exhaust valves drop in to a 6.4 head with minor machining on the tip (which has to be done anyway to put valve height in the appropriate range... 6.4's valves in a 6.0 head just need a little more taken off the tip as theyre longer). Sometimes people will use a 30* angle, even in the gas world, because it tends to help low lift airflow. Fwiw, duramax motor are 45* intake and exhaust, and their intake valves are smaller than 6.0, but theyre exhaust valves are 3mm bigger than 6.0.
I'm working with a local airflow expert on developing a port work profile for these motors... He's kinda taking longer than I had hoped, so I have began exploring other options just in the mean time. RCD claims a 27% airflow increase with their cnc porting program, 6.4 exhaust valves and their exhaust manifolds. I can get the porting done there for 1000 bucks, but I gotta send them cleaned bare metal heads... Which is no problem, but shipping both ways adds up. If I can get a few people interested I can ship the heads on a pallet and get the price down some if we did a few sets at a time. I haven't used rcd's port work yet... So I have no idea on the validity of their claims. Their valve springs are 500 bucks... And a good investment if you seek more than 40psi boost/back pressure.
I want to be very very crystal clear, im not associated with rcd at all, my name is jared... And there's a jared there that posts on the army all the time, but we are not one and the same. I'm not pushing their products, just throwing what ive found out there. Fwiw elites valve springs are now 500 as well.
There's lots of issues with these heads... Read through the link in my sig, I think it's also a sticky in the general 6.0 section, but it outlines the process of what I would deem necessary for a quality rebuild - hardened seats, replace worn guides, 3 angle valve job, milled, resetting valve height... Which we set to specs we've measured to give proper lifter preload... They had way too much lifter preload from the factory. You woukdnt want to sink thousands of dollars into port work into a set of heads that'll leak coolant or fuel due to a crack. Anyway good luck with your build, let us know how it works out.
2005 F-250 Harley Davidson Edition
Warren 205/75 Injectors
KC Turbo 71mm VGT
Twisted Diesel Level 3 Transmission/PI Converter
AFE Intercooler/Flexalite Fans/Mishimoto Radiator
Icon 4 Link, 37" Nitto's
SSBC 6 piston calipers
Yukon 4.30's, Detroit Locker
Machining the 6.0: