can some one please explain commonized heads

[benbuilt4u]

i keep reading that job2 has commonized heads. what is the main difference and what did this change accomplish in reliability? is this 6.0l free from problems of the past? i just read on another site that 05 6.0l have 500 new and upgraded parts on the engine from previos years 03/04 models is this the same for late 06/07 models?

TIA

[GrampyJim]

Heads were commonized to facilitate the change to the 6.4. While most of the changes are subtle, the commonized heads and the older heads are not interchangeable....

One is as reliable as the other both in terms of casting integrity and cylinder sealing.... but cylinder sealing is a matter for a different discussion.

[Bear_Hunter]

[ QUOTE ]
.... but cylinder sealing is a matter for a different discussion.

[/ QUOTE ]

Grampy can you expand on this?

[GrampyJim]

I'll try, but there will be a lot of crap following my post....

Some pre-requisite knowledge.... Navistar offers this engine in three horsepower configurations - the highest being 230 horsepower last time I looked. Ford offers this exact same motor (aside from electronics) delivering 325 horsepower... the only way to increase horsepower is to increase cylinder pressures.....

The head bolt arrangement on the 6.0 is what we call "10 head bolts/ 2 sharing".... Ten head bolts total, with adjacent cylinders sharing two head bolts. Now, it's not real hard for engineers to compute cylinder presures and to design bolts and gaskets that will contain these pressures under normal circumstance....

Ford takes this motor and increases the horsepower output by nearly 50%... now, we are getting awful close to "walking a line".... The gaskets and the bolts should be able to withstand these pressures under normal conditions... heavy on the "normal conditions"....

Unfortunately, we have conditions the engineers didn't experience in field testing and weren't expected.... overboost......

Through a combination of effects, we can run into an overboost condition that can actually lift the heads off of the cylinder block due to excessive cylinder pressures. The first time this happens is the hardest time.... the second time takes less... the third time takes less than the second time... and so on...

Ford took steps to improve cylinder sealing but this didn't address the root cause of the concern.... overboost....

If the variable vanes in the turbo hang, we can have an overboost condition that can hurt cylinder seal.... If we run a chip, we can have overboost that can hurt cylinder seal....

The heart of the matter is that the motor, right off the showroom floor, is pretty "high strung" and can't take a lot of conditions that can be thought of as "abnormal".

These operating systems are complex beyond what most believe... While they are a "bit like" the 7.3 (as far as HEUI injectors and a separate module for injector control is concerned), there is still no comparison. The number of conditions that can cause a serious overboost condition are numerous. It doesn't help if an owner disregards the engineers recommendations and decides to rely on anecdotal information derived from what Grandad used to do 40 years ago or what can be saved from glitzy ads in glossy papered magazines.

As technology advances, we are seeing more and more "purpose built" sub-assemblies.... they are designed to withstand finite, quantifiable loads... venture outside the window and things will go bad.

Sorry for two things... one, I didn't give the subject of cylinder sealing all the attention it deserves (and, for most of it, I am probably ill equipped). Suffice to say that we can't compare old technology motors to new technology motors in regards to many traits. ..... I feel that the 6.0 has "adequate" cylinder head sealing for normal, expected conditions. Second, what I have said depends on readers being able to figure things out when it comes to metal objects.... The dynamics involved when a piece of seemingly immovable metal when subject to thermal and pressure changes is astounding... and I am only familiar with the concept on a very basic level.

Something that was proven to me in a most visual way early in my career.... that immoveable lump of cast iron that we call a cylinder block or head - no matter how robust - can be manipulated through simple hand pressure in a manner that most would find disconcerting...
An inside micrometer was suspended crossways in the bore of a circa 1953 six cylinder Chevrolet block. This process was repeated for each of us 16, young apprentices on nearly our first day of formal training. Each of us had to place the fingers of one hand in the cylinder on one side of the micrometer and out thumb in the cylinder on the opposite side of the micrometer. A simple squeeze and the micrometer would drop out of the cylinder. If one can deal with this concept, one can understand what happens in a motor under extremes of temperature and pressure.

[Bear_Hunter]

Thanks for the detailed post... I appreciate it.

So if I understand correctly...contrary to popular belief...commonized heads provide no added benefit?

[Btravelen]

Doesn't 'commonized' mean that they can be used on the 6.0L , but not the other way around?

[moldman7n]

So now we take an engine designed for 230hp, modified to 325hp and add a chip boosting it to what? 400 plus. Do you think that may lead to premature failures?????? According to some "experts" on here, it has no effect on it. The question of the day would have to be knowing the properties of engines through decades of development, why wasn't the head bolt design of the 325hp 6.0 retooled for more/larger bolts before it was sold? Also, why was overboost protection never incorporated into the design? And one more stupid question, why is there no fuel pressure gauge on these trucks considering the havoc that is raised with the injectors over this issue? And lastly, are these newer egr valves finally designed to last? I feel these are good engines left stock but they could have been so much better with a little bit of common sense engineering. If the 6.0 had been as good or better than GM/Dodge, Ford could have really cleaned up in the heavy duty pick-up market. The truck itself is superior in most aspects for most users. If the 6.4 turns out to have head, injector, egr problems Ford is going to be in BIG BIG trouble. The DMAX is an overbuilt beast with awesome power. Cummins is legendary for dependability. The competition was ahead up until now in the engine category. Let's see what the 6.4 brings to the table against the new competitors from GM/Dodge. Don't forget Dodge is loosing it's achilles heel this coming year with a 6 speed auto tranny built to do the job. GMC has a new body style that rips off the superduty look. The competition is heating up.

[GrampyJim]

OK.... since none of us were "there" for field testing, all of this is opinion... my opinion, to be exact... and no small amount of thought has gone into it....

I feel that the head fasteners didn't receive special treatment because engineering computations didn't show a need for it. Consider also that these cylinder bores are very close together - even with a 4 per cylinder/ 2 sharing arrangement, a 2 mm step up in fastener size would have the possibility of compromising the cylinder block on all "2 sharing" fasteners....

Even the most rigourous field testing cannot reproduce all the conditions that can be found nor can they reproduce some conditions long enough for some concerns to appear... In an ideal world, the 6.0 wouldn't need some "blow-off" arrangement to limit boost... that's what VGT was all about - tailoring boost to requirements. Unfortunately, we are seeing many concerns that just weren't foreseen, expected or experienced during trials.... Every time someone breaks new ground with technology, they open themselves up to "Houston, we have a problem..." type events.

I'm not trying to make excuses for any of this... I do feel that Ford is stepping up to the plate to address these issues..... in spite of all the "my truck is a POS - waaahhhh, waaaahhhh - don't you dare reflash my truck..." we see... Besides, someones grandpa drove a 6-71 or triple nickel Cummins and all the stuff they did in the 50s has got to be the right stuff for me to do on MY diesel, right?

Base fuel pressure should have never been an issue. I don't think that it ever occurred to anyone to try and run one of these engines with the fuel pump turned off.... Oversight? Maybe.... Who would even consider that one of these would run with a bad fuel pump? The 7.3 wont....

I recall the first time I worked on a 6.0... it sure didn't look like a 7.3. That one step up was a complex step to take - "One small step for man... one giant leap for mechanics brain...". That we see some of the concerns we are having is disappointing, in retrospect maybe not totally unexpected, problems we've never seen before in history? - most decidedly.

Formal training on the 6.4 is still half a month away.... We will have to successfully complete a web based training course to qualify for classroom training.... Having said that, from what I have been able to learn of the new engine, lessons learned on the 6.0 will be applied to the new package....

I understand that the EGR will be a "linear" design.... a positive motion stepper motor with position sensing.... The current design is a "dithering solenoid" design that depends on duty cycle to maintain a desired position. I could be mistaken but this is likely the way this layman would handle past concerns.

The secondary turbo will be a VGT design..... I understand that new materials and/or coatings are being used to reduce/minimize sticking vanes. I am unsure if a VGT position sensor will be incorporated... it would be a nice addition... if VGT sense didn't change when commanded, the engine could be defuelled to protect things.

The changed to ULSD fuel is going to help, as well. The reduction in soot is going to help all of the exhaust treatments maintain operability.

Now, the bad news.... at some point, we need to realize that some of those things that would be nice to see are going to add both complexity and cost to the production units.... few bucks here and a few bucks there and the next thing you know, the truck has priced itself out of the marketplace....

"I'd love to drive a PSD but they're a POS" could be replaced with "I'd love to drive a PSD but they cost too much...".

Additionally, we need to look at the people that will fix these things..... There is a not-so-old adage that goes "50% of all doctors graduated in the bottom half of their class...". This hods true for every walk of life... technicians included. There is a very real need to make these systems self checking..... but the added baggage of extra electronics is going to overwhelm a lot of techs. For some strange reason, it is those very simple electrical principles and the concept of voltage drop testing that is the biggest stumbling block for all concerned.... There is some mystical mental block that comes in to play when we discuss electricity.

I can grab my DMM and, with three simple measurements, decide where I am going to concentrate my efforts... is that luck??? I don't think so because electrical laws are electrical laws... can't be broken, can't be bent ... well, not without altering the universe as we know it....

Wow.... I'm getting windy lately... looks like "cabin fever" is setting in early this winter....

[Clevelandjim]

Two words - head studs. The 6.4 might need them too.

[ExR90]

A kind of moot question, but why does ford prohibit the installation of aftermarket studs that are have superior strength? I mean, it would guarantee the truck wouldnt come back for another headgasket repair. Ford could just say, you pay for the studs and we will install them when doing the headgasket. Or why doesnt Ford just make some studs to do the job that the aftermarket ones do. Im sure if they were mass produced they wouldnt cost what the two big companies are getting for them.

Only reason I could see is it creates a sort of admission of guilt that the original ones are not that great unless ever other area of the truck is perfect.

I mean, sure it would be niec to say, if only the turbos didnt stick or as long as people were not hard on their trucks, or as long as people didnt chip them or whatever then we wouldnt need the better studs but the reality is the studs seem to have a need and wouldnt it have been cheaper to change the design to the better studs during say, job 2 switchover or whatever? I dunno, just seems like it would have been easier and cheaper all around to just deal with the problem instead of looking at all the peripherial possible causes of the need for the problem.

[moldman7n]

Good questions.

[brokeagin]

Out of all of the problems I had, I never blew a head gasket. Mine was mostly related to oil leaks, injectors, exhaust sensors, EGR problems, turbo boots and noise in the front suspension or steering (it was never found)...