I have been working on a set of "ProMax" cylinder heads for the past number of weeks. This is the first set of this brand I have had to work on so I thought I would make public some of my findings.
I don't know where these are really produced and I'm not going to guess. At first look they seem just like any other aftermarket head, they have seats under both valves, they have some sort of black paint or something all over other than where the machining has been done.
The runners are the WORST I have seen, casting shift is major, excess slag is everywhere, the machining in the bowl area is off from one hole to the other.
Once I started roughing in the ports some of the slag would flake off like the paint was holding it in place. There are deep voids / pits in places, extra material hanging in places it shouldn't be, and much more poorly placed material than other brand heads.
I have spent a large number of hours on this set reshaping and removing material to get these where they should be.
This set isn't done yet but when they are the port work and coatings will be on par with any other brand of head they just require many more hours of unexpected work on my part.
I'll post a few before pics now, and after pics when finished.
I can't speak of quality or if the inside cooling passages are different at this time, I doubt I will purchase a head to cut up just to see, I have and will continue to recommend P400 heads as the BEST, real GEP heads would be second.. I never recommend any aftermarket head..
I have done many many 6.x heads over the years so this is my honest review of the "ProMax" heads...
I don't know where these are really produced and I'm not going to guess. At first look they seem just like any other aftermarket head, they have seats under both valves, they have some sort of black paint or something all over other than where the machining has been done.
The runners are the WORST I have seen, casting shift is major, excess slag is everywhere, the machining in the bowl area is off from one hole to the other.
Once I started roughing in the ports some of the slag would flake off like the paint was holding it in place. There are deep voids / pits in places, extra material hanging in places it shouldn't be, and much more poorly placed material than other brand heads.
I have spent a large number of hours on this set reshaping and removing material to get these where they should be.
This set isn't done yet but when they are the port work and coatings will be on par with any other brand of head they just require many more hours of unexpected work on my part.
I'll post a few before pics now, and after pics when finished.
I can't speak of quality or if the inside cooling passages are different at this time, I doubt I will purchase a head to cut up just to see, I have and will continue to recommend P400 heads as the BEST, real GEP heads would be second.. I never recommend any aftermarket head..
I have done many many 6.x heads over the years so this is my honest review of the "ProMax" heads...
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