"NEW" 3.0l v6 Cylinder Heads....Quality?

[ptf18]

Exploring my options to repair/replace the cylinder heads on my 3.0l engine. Came across a couple web-sites that offer "NEW" cylinder heads for these Ford engines.

The money issue is not my concern. Rather, its the quality of these replacement heads. I assume they are China produced (like everthing else now in our country) and it raises a bit of concern with me. Has anyone used these "NEW" heads and if so, how have they performed for you?

I believe these "NEW" heads are "bare". Any recommendations on what manufacturer I should look toward for the needed parts to build up these heads? I'm leaning toward Ford or Motorcraft. I've assembled cylinder heads in many years past so I have and idea how to perform this assembly BUT is there anything I should consider and/or need to do with these more modern heads if I chose to do the work myself?

 

[RonD]

New, in the case of heads, is not better than used in my opinion
Heads are cast so there can be flaws in the casting, remote but not 0
Heads will crack if there is a flaw once they are heated and cooled a few times to a few 1,000 times
Used head has been tested, no flaws in casting, assuming its not cracked, lol

Heads don't "wear out", its a block of metal, their "wear" is internal, done by expansion and contraction of the metal as its heated and then cooled over years of use, so most heads can and do last the life of the vehicle/engine
Overheating could cause stress cracks, which is how most heads reach end of life
Machine Shops can pressure test heads and/or magnaflux them for cracks

Valve and valve seats are separate, new is fine
Used head with valve job is best in my opinion

 

[ptf18]

Thanks RonD. BUT... if Ford had "soft" heads that were the cause of the valve problems in...at least the later 3.0l heads (per Ford).... how does getting them refurb/overhauled/"valve job/etc prevent the valve problem from reoccurring?

From what I have read on the 'net, this "soft head" issue and resultant valve problems have happened to the 3.0l engines installed in vehicles built years prior to the years listed in Ford's TB (2004-2008). Thus, I would think ANY of the 3.0l heads would be suspect of reoccurring problems....but maybe for the next owner.

That is why I was inquiring about the "new" manufactured heads. I don't read (on the net) much about them being used and hate to end up getting a pair only to later having some type of issue with them.

 

[RonD]

You got some bad info

2004 to 2006 3.0l Rangers could have bad exhaust valve seats, heads were fine, and not 100% failure rate, just a "known issue" with a TSB
If these heads got a valve job with 6 new exhaust valve seats and exhaust valves, they were fine, many did this fix

In the TSB Ford replaced the heads because Ford Dealer Shops don't do "valve jobs", they replace parts

 

[ptf18]

Ah.... so it was the valve seats and NOT "soft" heads? I've seen pictures on the 'net that show the valves (exhaust) "misshapen". The valves look as if they are being pulled thru the seats. As if the valves are "soft".

What exactly was/is "bad" with the valve seats?

 

[RonD]

Ford said it was "due to an engine exhaust valve seat recession"
So seats could move in their head cavity

Exhaust valves in ALL engines with valves(all 4-stroke engine) are the reason for "Valve Jobs"
From the 1930's up thru 1950's, it was a very common to do a "valve job" at 60k miles
With newer metallurgy learned from WWII aircraft engines, it went up to 120k+ miles, its now 250k miles if not more

And back in the "good 'ol days" carbs were biggest reason for valve jobs, fuel injection with computers are why we don't need the "valve jobs" as often


Intake valves are cooled each time they open as new air/fuel mix comes in
Exhaust valves run HOT, very hot, exhaust exiting the valve is usually at 800degF
The only way to cool an exhaust valve is thru its seat, seat is in the head which has coolant circulating to draw out the heat
Combustion temp, i.e. exploding air/fuel mix, can get past 2,000degF

Both valves rotate in their valve guide as they are pushed down/open by their rocker, this is to prevent hot spots
Valves are "lapped" so the valve and seat have the same angle for best seal BUT ALSO best surface area to dissipate HEAT when they are in contact, and they are in contact 75% of each cycle of 4 stroke engine

If a seat shifts then not a good seal, and when the fuel mix explodes some of the 2,000+degF gases can escape thru that bad seal, this can "burn" the valve and seat at their edges, weakest points

If fuel mix is Lean, fuel mix explosion is even hotter and so is exhaust temp, this is how carbs ruined valves faster
Fuel injection computer has O2 sensors so will compensate for air leaks or low fuel pressure
Lean mix can also "tulip" intake valves, they are a softer metal than exhaust valves so the hot combustion temps softens them too much

Pinging/knocking causes pitting inside cylinder, eats away at pistons and valves, even head gasket

Exhaust valves can stop rotating because of carbon build up, so get HOT SPOTS and start to leak, the most common "burnt valve" reason with fuel injection

Once an exhaust valve can't seal it just gets worse and worse as the leak gets bigger and bigger from the 2,000+degF combustion temp

Surprises me they last as long as they do, lol

 

[ptf18]

RonD....again thank you for an explanation on what's going on with these 3.0l heads.

"Ford said it was "due to an engine exhaust valve seat recession"(B.S. "engineering"
explanation)
So seats could move in their head cavity"

BUT....may I harp on this issue some more?

I assume valve seats are pressed into the head. In addition I would think that the "fit" between the seat and the machined out area were the seats are installed are an interference fit. AND that this interference fit is such that even with the head operating at its operating temperature the seat stays "secure" within the head.

Ford's "explaination" that the issue with these heads is "exhaust valve seat recession". IMHO, this means that the seats are RECEEDING into the head ie; being "pounded" farther into the head by the force closing the exhaust valve (the damaged exhaust valves that I've seen pictures of on the 'net show misshapen valves that look as if they are being "pushed or pulled" further down into the seat/port area where their installed).

I would think that if these seats are RECEEDING into the head the reason is that the material the head is made of is..."soft"....whatever "soft" may mean. I can not think of any other reason for the seats to RECEED.

Or are the seats loosing their interference fit and coming "loose" in the head?

Any idea what is causing the misshapen valves that I see pictured on the 'net? ALL exhaust valves operate at high temperatures compared to the intakes and from what I know our modern engines are not suffering from exhaust valve issues. Could Ford have used "soft" exhaust valves when they switched to 7mm valves in the later 3.0l engines?

If I am correct on my "assumption" of these heads being "soft", my concern of them having a loooong service life is justified after they have been repaired.

Your input please.

 

[pjtoledo]

7mm valve stems preceded seat recession by a couple years.

there is a big difference between pounding on a secured seat vs one that has loosened and is bouncing around.
the bouncing one will damage what it's slamming into more than a secured one.

the same iron surrounds both valve seats. with the intake being heavier it should hit harder but no damage is done there.
that puts the exhaust seat and its ability to absorb heat and stay seated as the problem.


I'm not a mechanical engineer, but I did beat on something with the wrong tool recently

 

[RonD]

Mis-shapened valves are from the leaks, warps the valves from excess heat once leak starts

The recession would be caused by the air/fuel mix explosion not the valve closing, very high PSI during that explosion to push down the piston

Yes, I think Ford explanation was simplified because there was no explanation of why, and "recession" in my opinion just means valve seat moved slightly

Since Ford used the same 3.0l OHV head casting from 1999 thru 2008 I wouldn't think the head would be the issue or the casting of the heads since it was just a 3 year period, and not 100% failure

In press fit parts like seats metal temp comes into play, metal expands and contracts when heated and cooled
And the head and seat are dis-similar metals, so different expansion contraction rates
There is also the machining if the head for the seats
And the machining of the seats
Because it only effected certain years and not 100% failure in those years, could be exhaust seat supplier glitch, in metal type or machining, i.e. a "bad batch" used randomly from 2003 thru 2005 in 3.0l engine assembly plants so effected 2004 to 2006 model years
OR
Head machining tool, too deep or too wide
OR
???


Just anecdotal but since people who did rebuild these heads never re-posted about re-occurance of the issue I would speculate it was never a head issue

 

[stmitch]

I have no experience with aftermarket 3.0 heads, but I've read a couple of posts that mention the castings seeming to be a bit thicker (slightly different port sizes, etc). Whether that is true or not remains to be seen. And if it's true, is that due to lower quality, or have they identified problems and implemented solutions? The posts that I recall saw the added thickness as a good thing that allowed for more flexibility with port/polish jobs. A stock engine rebuild might have different priorities of course.

 

[RonD]

Article here goes thru the 3.0l OHV changes over the years: https://www.therangerstation.com/tech/ford-3-0l-build/

 

[JerEazy]

Just put a set from Allied in GA on. $650 before core refund and free shipping. I’ve only got about 3 miles on them…. But they seemed to be in good and return core was free as well.

I recommend.

Cylinder Head - New & Remanufactured For Sale | Allied Motor Parts

Allied Motor Parts - Remanufactured/Repaired light truck & automotive cylinder heads, gaskets & more. 1-Year Warranty & Moneyback guarantee, Free frieght on orders over $650.

www.alliedmotorparts.com

 

[Chris146]

I second Allied in GA, bought on of these

Ford Taurus Ranger 3.0L F6 OHV 98-06 Remanufactured Cylinder Head

Buy Ford Taurus Ranger 3.0L F6 OHV 98-06 Remanufactured Cylinder Headfrom Allied Motor Parts. Our cylinder heads are assembled to OEM specifications. Call Now 8776768322!

www.alliedmotorparts.com

no issues at all.

 

[ptf18]

Fellows. Were these NEW?

 

[JerEazy]

Fellows. Were these NEW?

Negative - they are reman