01PSD
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Is it supposed to be a video?
Dont try to convince me about fixing cracked heads with hardened seats.
Hardened seats fall out. (Without being staked in...and who wants to create hot spots on a 6.0L head?)
Being there done that.
I'll just replace the heads, thanks.
I won't try to convince you...but just FYI all the big rig diesel motors have valve seat inserts from the factory, the ever popular 5.9/6.7 Cummins has valve seat inserts installed from the factory, the duramax and new 6.7 ford have hardened valve seat inserts from the factory...OE Caterpiller, international dt466, Detroit diesel, john deer, Cummins...any of them. Its actually another cheap point of the 6.0. Think about it...32 seats per motor, if each seat only cost a dollar, and they sold a million motors, that's 32 million dollars they just increased the cost of the plattform. I don't care what you think, just throwin it out there. Yes sometimes the oem motors that come with them do drop valve seats, but normally only when something else has gone horribly wrong...blown head gaskets, broken valve spring/dropped valve whatever. Some engines are more notorious for dropping seats than others, like a 8.3 liter Cummins that has a shallow .165" deep valve seat and only .006" press fit. I can say I've personally installed more than 30k valve seats and never ever...ever....ever had one come out...I install mine at .009" press fit or more depending on application. Again, I'm not trying to argue with you or anyone about it, I'm not trying to convince you, it sounds like you've made up your mind, in which case I'm not going to waste any more breath, but just so others know that installing valve seat inserts is not a ghetto patch job fix, its a common practice that navistar skimped out on when designing the 6.0. In order for the integral cast iron valve seat area not to wear out they had to harden the piss out of the seat area in the head...when you make iron really hard its also brittle, hence the cracks.
Cracks in the fuel rail or down into the injector hole or glow plug hole are a different story. We don't use those, we scrap them. Most cracks in the valve seat area are only .125" or so deep (1/8" or so)...I install a .250 (1/4" deep) seat that effectively cuts out the crack. The new insert is an alloy (satellite) that takes the abuse far better than cast iron could, and further more prevents further cracking.
BTW, "staking" the seats in is ghetto. If you have to mushroom the iron over the seat to keep it in you're not using adequate amounts of press fit, or doing something wrong...because rest assured, the OEM's don't have some dude with a hammer and punch "staking" the seats in at the factory so they don't come out.
Is it supposed to be a video?
Shawn has done little over 1000 with stock heads...not 1200.
I won't try to convince you...but just FYI all the big rig diesel motors have valve seat inserts from the factory, the ever popular 5.9/6.7 Cummins has valve seat inserts installed from the factory, the duramax and new 6.7 ford have hardened valve seat inserts from the factory...OE Caterpiller, international dt466, Detroit diesel, john deer, Cummins...any of them. Its actually another cheap point of the 6.0. Think about it...32 seats per motor, if each seat only cost a dollar, and they sold a million motors, that's 32 million dollars they just increased the cost of the plattform. I don't care what you think, just throwin it out there. Yes sometimes the oem motors that come with them do drop valve seats, but normally only when something else has gone horribly wrong...blown head gaskets, broken valve spring/dropped valve whatever. Some engines are more notorious for dropping seats than others, like a 8.3 liter Cummins that has a shallow .165" deep valve seat and only .006" press fit. I can say I've personally installed more than 30k valve seats and never ever...ever....ever had one come out...I install mine at .009" press fit or more depending on application. Again, I'm not trying to argue with you or anyone about it, I'm not trying to convince you, it sounds like you've made up your mind, in which case I'm not going to waste any more breath, but just so others know that installing valve seat inserts is not a ghetto patch job fix, its a common practice that navistar skimped out on when designing the 6.0. In order for the integral cast iron valve seat area not to wear out they had to harden the piss out of the seat area in the head...when you make iron really hard its also brittle, hence the cracks.
Cracks in the fuel rail or down into the injector hole or glow plug hole are a different story. We don't use those, we scrap them. Most cracks in the valve seat area are only .125" or so deep (1/8" or so)...I install a .250 (1/4" deep) seat that effectively cuts out the crack. The new insert is an alloy (satellite) that takes the abuse far better than cast iron could, and further more prevents further cracking.
BTW, "staking" the seats in is ghetto. If you have to mushroom the iron over the seat to keep it in you're not using adequate amounts of press fit, or doing something wrong...because rest assured, the OEM's don't have some dude with a hammer and punch "staking" the seats in at the factory so they don't come out.
I've heard the same incidents about putting valve seats in the 6.0 heads and them falling out but like you said just about every application now days is using them. Would you say that maybe the 6.0 head is just too thin around the valve and swells too easily with the heat thus causing the valve seat to work it's way out?
I think it has more to do with the aforementioned heads being designed to have the hardened seats, as opposed to retrofitting them into 6.0 heads. Pressing valve seats into a hot head that is designed for them is different than modifying a head to press valve seats that were never originally designed for is not the same. Not knocking anyone, there are definitely people that can do it properly, but not everyone can, thus you see a higher percentage of failures.
Metal is metal. It doesn't know or care what manufacturers emblem is on the hood. That being said press fit does matter tremendously. 6.0's don't really run any hotter in the combustion chamber than other engines...and if metalurgy were the problem then the aluminum duramax heads would drop seats left and right, but they rarely do. 24v 5.9 and 6.7 cummins drop seats way way more. I can't speak for other shops but like I said I've never had one fall out that I put in.
The trouble is lots of rebuilders use preset cutter bits and/or never check them. Let's say you're installing a 1-1/4 seat (1.250" 'nominal' size) well the seat will normally measure 1.255 or so, and tooling manufacturers make cutters that are preset at 1.250"...giving you roughly .005" of press fit. Well in a 350 Chevy gas motor that might be enough... but not in a 1500*+ diesel combustion chamber. They need more press fit, but lots of shops are limited to the preset cutter bits. We have adjustable cutter bits (as do tons of other shops, nothing that we are exclusively privelaged to) so I can dial in the exact amount of press fit desired, down to .0001" (one ten thousandth of an inch, or about 1/30th of a human hair). Some applications require more press fit, like aluminum. The OEM's use liquid nitrogen to shrink the seat before they drop it in the 'counter bore' and as the seat reaches room temp it grows and develops adequate press fit. This is common with aluminum heads. Lots of factors involved... but really it all boils down to adequate press fit.
I don't think he ever has.
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Shawn has done little over 1000 with stock heads...not 1200.
I believe it was 1064 if I'm not mistaken.
Sorry, I should have been more clear. I don't believe he has ever dyno'd that high with stock heads, but I'm pretty sure track times put him there. But of course, he was likely using a lot of bottled air, so not sure how much that helps this argument. With that said, nitrous is a heck of a lot cheaper than ported heads.
I think your trying to say the same thing, but metal is not metal, hence metallurgy. There are 17,000+ aluminum alloys, and the correct one can hold a hardened valve seat in a diesel application, but others won't. Metallurgy is a big issue with the 6.0, and accounts for the huge differences in castings, and quality. Yes the oem's use methods that a engine rebuilder/reman company cannot duplicate cost effectively, and that is why oem reliability is in no way repeatable. Just curious, are you a machinist by trade? I'm not but know metallurgy well.