best year Common Rail Cylinder head

Boostediesel

Boostediesel

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i have talked to several people about this and got mixed answers. i know the 04.5 - 05 heads have the better vlave seats and the inconel exaust valves. i heard the 06 heads have the better port designs but do not have the inconel valves. can someone please verify if any of this is hear say or true, thanx
 
I've looked at an 03, 04.5, and an 06. The 06 wasn't choked down on 1,2 like the 04.5. This may have been a coincedence, but the valve seats in my 04.5 popped right out, but the 06 were in pretty tight.

-jp
 
cool, what about the inconel exhaust valves, are they only in the 04.5 and 05 heads?
 
all have inconel exhaust valves. I'd be careful on the intakes of the newer heads though.... I think Cummins may have tried to cut some cost and went with cheapo's. I doubt inconel would have done this...

valve.jpg


I think the 03 or 04 ( no sure ) heads are seatless which may be better to build than those with seats
 
some 03's must not have had seat cause Swole bought a seatless head which I'm pretty sure was a 03
 
All the heads from 03 up had pressed in seats.

The best head will be from 06 the 06 head will flow more than a ported 03 head.
 
Ty, It was a 24v head ...I believe 01

Didnt wanna try the conversion after I found out about the crossover tubes being different..
 
triton said:
all have inconel exhaust valves. I'd be careful on the intakes of the newer heads though.... I think Cummins may have tried to cut some cost and went with cheapo's. I doubt inconel would have done this...

valve.jpg


I think the 03 or 04 ( no sure ) heads are seatless which may be better to build than those with seats
Click to expand...

Quick question, why can't you just retrofit the older intake valves into the newer heads? Or are they different sizes?
 
BlackSkyRacing said:
Quick question, why can't you just retrofit the older intake valves into the newer heads? Or are they different sizes?
Click to expand...

Not a different size but, intake and exhaust valves have different angles. You can just have the seats machined to accept exhaust valves in the intake side which is what I did. Another reason to do this is exhaust valves are inconel and intakes aren't ( from Cummins anyway )
 
By the looks of that valve, it looks like it saw a bunch of heat, and way too much seating pressure. (The valve spring was pulling the valve through the seat, which was obviously harder then the valve material.)
If you could look at the bottom face of the valve, you would see that it is prolly tulliped.
 
true but, I had 23 other valves with the same seat psi that were fine. My opinion.... inferior metal
 
someone needs to come out with an aftermarket casting, this is so stupid having to worry about valves dropping in our cylinder heads
 
I think it has a some to do with how the seats are installed and more in the timing/power adders you have stacked or combined.
 
I don't... I think it has to do with the fact that Cummins hadn't used pressed in seats on the 5.9 before the CR came out... They probably went off of some engineer's rec as to the tolerances and came to find out that after some heat cycles, that spec wasn't tight enough.

after a few years they got it right and you don't see the problems so much. yeah, you'll get a bad apple here and there, but they got it sorted out a little better.

you're sorta right though... timing/power/stack/etc. has nothing to do with it... heat has everything to do with it. BUT, a "well kept" seat should never fall
 
I would rather have pressed in seats. Early 24V heads had the pressed in seats. In 01-02 only the stick trucks had pressed in seats. Then in 03 they started using the pressed in seats again. Two years ago I had my 02 head magnafluxed and found it had 46 cracks, all around the exhaust valves. The head was junk so I bought a brand new one with pressed in seats. Last weekend I dropped two exhaust seats (1,6) while racing. Took the head to a machine shop and it was fluxed. The head had zero cracks!! Although I dropped two seats, I'm glad I'm not buying a new head. The new seats are .010 larger and should never drop again (I hope). I think the pressed in seats protect the head from cracking.
 
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