The 6.0 cylinder heads that we have seen over the past few years are absolute garbage. We have seen a complete lack of precision in terms of the surface, even where they put the valves. We have seen a few that were so bad they wouldn’t even bolt onto the block. The dowel pins weren’t even in the right spot. 6.4L cylinder heads are becoming unavailable or, if available, 7 out of 10 are cracked or won’t pass the leak test.
I have finally found a manufacturer out of China that will ship cylinder heads to us; and I am happy to say that we have finally found a replacement 6.4L cylinder head. We have worked very carefully with these folks to make sure that the metallurgy and everything is correct in these cylinder heads. Powerstroke Specialty will be able to sell a BiggDogg version of these cylinder heads with O-rings, new guides, new valves, and new injector cups. They are pressure tested and built to our specifications. You will know that when you bolt this cylinder head onto your truck, there will not be any problems, leakage or issues. We go to an extreme level to make sure that we are able to supply these heads and maintain the quality that you have come to expect from Powerstroke Specialty.
Follow me around the machine shop to see what we do to these heads.
First we soda blast the cylinder head to get all the crud off of them. They come with cups installed but we pull them because we don’t trust them. We make sure that all the boars where the injectors go are nice and clean so that they can accept the installation of the new cups and the sealer will work correctly. The heads are then cleaned and pressure tested. Next, we install the injector cups and pressure test them to insure that these heads have the ability to hold pressure in the cooling jackets and on the injector cups. None of the other guys selling these heads have done any of this.
Next is surfacing. These Chinese heads are sometimes pulled out of the castings before they are fully cured so you often see a groove. They might be low in the middle or irregularities in the surface. Generally we are taking a 1000th or two 1000ths out of the deck to get a nice mirror finish. From here, the grooves get cut for the O-rings and the O-rings are installed. We use high grade stainless steel which is crucial to the sealing quality of the head gaskets combined with the studs. Next we use the valve seat machine. We have a 3 angle standard valve job, industry standard, done with ultra precision. We had to have consistent repeatable results to give us the quality we are searching for. One of the things that we do differently is doing the valve job after the cylinder head is surfaced. This way we can get a consistent valve depth and the valve sits at a very consistent level across the surface of the head.
Next are the valve guides and getting them sized correctly and pointed in the correct direction. We have had to reject a couple of cores because the valves were going in the wrong direction and can’t be repaired. We won’t let any of them pass and get into the customers hands unless they are correct. We buy new valves from Ford. We don’t use anything after market or second quality, only the best available on the market. The valves get ground to the same precision as the seats. Another thing we do differently is to micro-polish the valve stems to reduce friction and wear and increase the longevity of these heads. Because of the bridge they use in this design, this is crucial. This is the part that causes cylinder head failure because of premature guide wear.
Next is the assembly station where the heads and the valves matched to the cylinder heads are assembled and measured correctly. Every head is measured for valve height and the valve stems have to be measured and possibly re-cut to make sure that it fits the correct length matching the push rods in the engine. I have bought heads off the aftermarket where the difference has been ten to fifteen thousandths variance in valve stem length. That will cause a tap, premature wear of the valve train and the rocker arms and bridge. Also if it is too long, you will have the valve hang open which can burn a seat or cause other premature damage. Attention to detail at this level is crucial making these machines run and work correct.
At this point, these are assembled heads ready to go out and be installed on your truck. The only way we will be successful is attention to detail and doing it the right way. That is what has made Powerstroke Specialty successful. I really appreciate all of the support y’all have given us at Powerstroke Specialty and Powerstrokehelp.com over the years. We are dedicated to doing the best that can be done for your truck and making it last as long as possible so you can realize the investment of this type of expensive repair.
I have learned that there is no way you can cut corners on these vehicles. It is a diesel, not like a gasoline engine where you have lower cylinder pressures, it has to have a level of precision that has to be replicated with the best people and equipment that money can buy. Unfortunately, it doesn’t come cheap. If you are out to cut corners and save a few bucks and go with an internet cylinder head, you will be working on that truck again. It is always better to do it right the first time.
When you call 770-931-4070 to order these cylinder heads, Dana Collins is the one who will handle your order and make sure you get what you need. Thank you for your support!~Bill Hewitt