NewsW wrote: smknf250 wrote:
If you are going to mod your 6.0 or if you ever have the heads off, have them checked by a machine shop and magnafluxed for cracks. Maybe people that have repeat problems with puking at putting in studs, but putting warped or cracked heads back on. There is no point in doing all that work and then putting a bad head back on.
Just a minor technical note.
A lot of people who had the heads off were machining them flat and in the process, introducing to them a warp when the heads were tightened down again.
The heads do not need to be completely flat longitudinally.
By doing so, the so called flat heads after machining had a high probability of leaking.
The head flatness checking procedure for the 6.0 deviated from what machinists commonly understood and knew --- and many shops were basically introducing a major flaw / fault into the heads by their "fix".
This issue was addressed in a little known and ill understood TSB by Ford:
6.0L - REVISED CYLINDER HEAD FLATNESS CHECK
PROCEDURE AND SPECIFICATION
2003-2007 F-Super Duty
2004-2006 E-350, E-450, F-650, F-750
Some vehicles equipped with a 6.0L engine may require the cylinder head to be removed and a
new cylinder head flatness check has been developed. This check is to ensure the component part
is not out of factory specification prior to installation. The surface quality (finish) of the cylinder
head gasket surface is machined to close tolerances which enable an effective sealing joint for
the multi-layered steel (MLS) gasket.
Follow the Service Procedure steps to verify cylinder head flatness meets new specification.
^ Ensure all head gasket surfaces are clear of any gasket debris, RTV, oil, and coolant using
Motorcraft(R) Silicone Gasket Remover (ZC-30) and Motorcraft(R) Metal Surface Prep (ZC31).
DO NOT MEASURE FLATNESS IN THE LENGTHWISE (LONGITUDINAL) DIRECTION!
THE OVERALL END-TO-END FLATNESS OF THE CYLINDER HEAD IS NOT AS
CRITICAL AS THE LOCALIZED FLATNESS CHECKS. LONGITUDINAL
MEASUREMENTS ARE NOT AN ACCURATE INDICATION OF FLATNESS WHEN
INSTALLED DUE TO THE CLAMP LOAD OF THE HEAD TO BLOCK BOLTED
ASSEMBLY. THE BOLTED CONDITION CAUSES AN OVERALL FLATNESS
CONDITION THAT DIFFERS FROM THE FREE STATE CONDITION OF THE HEAD.
If you don't want to factor in the cost of replacing the heads and redoing a botched job that involved removing the heads and machining them in error, do not buy a 6.0 that have ever had the heads off or have "improved" ARPs installed.
Chances are that the job was botched.
This is probably the reason for many 6.0s having repeated incidents of HG failures --- or cracked heads --- or other issues that is caused by warped heads.
ARPs, by applying more clamping force, can remedy this if it is not too extreme.
But that is not true in many cases.
In many cases I know, the "fix" is much worse than the "disease".
I have seen cases where engines with no evidence of Head Gasket / Heads failure were taken apart, heads improperly machined flat, then repaired with ARPs, only to spring a big HG leak that wasn't there before.
The solution was to replace the now too thin and warped (or machined flat when installed) heads with brand new ones.