Cylinder head back from the machine shop! Valve stems next?

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Just got my cylinder head back from the machine shop today and they told me they cut 0.006 off.
1) FSM states 0.15mm or 0.0059 in of warpage maximum. Technically this should answer most of your questions. Your head is toast !
According to this post, my head is toast..?

The shop recommended me to not mess/replace the valve stems and to not clean the carbon on the valves. I've talked to a Toyota Master Mechanic and he said he would clean them up for $200 but even he seemed to have the "you don't have to" attitude. Should I go ahead and have him clean the valves or am I being a typical over the top anal mudder? If it isn't too hard to mess up I figure new valve stem might be a good while you're in there thing to do.

NKP Garage on YouTube as well as OTRAMM used a tool similar to this to disassemble the valves:
Amazon product

The shop pressure checked the head and it was "in spec" but now im a bit skeptical because according to half k cruiser, my head is warped to the point where its "out of spec".

Thanks!

EDIT: Looks like the head came back with an extra dent on the exhaust side...

IMG_2536.jpg
 
Last edited:
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I'd try it. What's a 10th amongst friends? Most peeps can't even measure to a 10th. Unless it was lapped in, the machine it was cut on probably has a resolution of only 5 to 6 tenths. And that 10,000's of an inch for you metrical guys, .0001" not 0.1mm.
 
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I'd try it. What's a 10th amongst friends? Most peeps can't even measure to a 10th. Unless it was lapped in, the machine it was cut on probably has a resolution of only 5 to 6 tenths. And that 10,000's of an inch for you metrical guys, .0001" not 0.1mm.
Oh gotcha... would you bother with cleaning up the carbon on the valves then?
 
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Not an expert in this area (or any) but why wouldn't the machinist clean off the carbon?? Looking at the photos closely it appears the head wasn't even cleaned around the seats, so does that mean the seats weren't cut? Were the valves themselves cut (none of the "Valve job" boxes on the form were checked)??

Seems like a thick carbon layer on the face (or any imperfect mating between the valves and the valve seats) might cause issues related to valve heating (absorption/dissipation/transference)??

IDK.
 
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Oh gotcha... would you bother with cleaning up the carbon on the valves then?
Re: cleaning the valves. My machine shop did. They absolutely looked brand new. He also shaved the head - don't know how much. Very minimal. He said straight 6s are so long that they "always" warp.
20k miles since, the beast runs great. Knock wood!
Good luck with your setup
 
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Re: cleaning the valves. My machine shop did. They absolutely looked brand new. He also shaved the head - don't know how much. Very minimal. He said straight 6s are so long that they "always" warp.
20k miles since, the beast runs great. Knock wood!
Good luck with your setup
how much did your shop charge you? The shop I went to charged me around 200 to do a pressure check and surface it.
 
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Not an expert in this area (or any) but why wouldn't the machinist clean off the carbon?? Looking at the photos closely it appears the head wasn't even cleaned around the seats, so does that mean the seats weren't cut? Were the valves themselves cut (none of the "Valve job" boxes on the form were checked)??

Seems like a thick carbon layer on the face (or any imperfect mating between the valves and the valve seats) might cause issues related to valve heating (absorption/dissipation/transference)??

IDK.
I spoke with a toyota master mechanic after I got it dropped off and he told me that the shop probably didn't want to do it... 🤷‍♂️ I honestly didn't know what to expect I've never done this sort of thing before.
 
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how much did your shop charge you? The shop I went to charged me around 200 to do a pressure check and surface it.
Ballpark ~400. The time cleaning and measuring valves and guides was a good portion of that I'm sure. Quite happy with the work on the head and block (block work was a different charge)
 

knuckle47

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Why not do it….you are this deep in it now…. Imagine needing to start ripping it apart a year or less from now?
 
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Why not do it….you are this deep in it now…. Imagine needing to start ripping it apart a year or less from now?
That's what I was thinking, but the machine shop guy was so adamant about leaving it alone and leaving the valves in for the resurface...

Looks like he dented the side of the head too, it sure as hell wasn't there when I dropped it off.
 

knuckle47

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I saw that in your picture. My brother and I bought an old boat years ago with twin 454 engines. After the first season we owned it, one engine blew a few valves. It was a big job working in the tiny engine compartment on those giant heavy heads so while down there, I rebuilt everything from the lifters, pushrods and the entire heads. We were usually 20-40 miles offshore in the wild Atlantic waves. I would have been very disappointed if something else failed because I had shorted something that could have been done easily since it was opened up. The following year the other side blew a head so we bought an emergency life raft !

Re-evaluate your needs before buttoning it back up
 
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Oh gotcha... would you bother with cleaning up the carbon on the valves then?
If they seal and the seat surfaces are true, and if I didn't have to change valve guides/seals, I'd be tempted to leave it alone.
If I had to take the valves out anyway to change valve guides or seals, I'd probably soak the valves in carbon solvent and plastic or brass/bronze brush the worst of the carbon off.

Lots of "if"s. Did the head shop replace the valve guides and or seals for you?
 
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I know that everything costs something, but I'm struggling to understand how someone could be convinced to allow a machine shop to cut a head when it was assembled. How could you possibly know, before you cut it, that the head would clean up below the valves? How could a "reputable" shop guarantee that no valve damage would occur from their handling?

At the very least, the head should have disassembled and cleaned, because this is the only opportunity you have to do that. And it makes a difference.

Maybe I'm missing something.

In response to the OP's first post:
a) your head is fine; at most, you need to have the valves trimmed to match the material removed from the bottom face.
b) I would never reinstall a head without at least cleaning the carbon off the valves and seats and then checking for seals on every valve. These aren't V8s where you can remove a head without removing anything but a valve cover.

FWIW, you can't replace a valve stem; you have to replace the entire valve and then they have to be, at least, lapped into the seats.

Why would you go through all that work again, and again, after you'd done it once? Unless the head had recently been rebuilt/reconditioned, and in that case, there should be no reason to have the head off, unless there was a bottom or front end problem that wasn't caught when it was off the first time, the head shouldn't "need" to be removed but once or twice, at most, in the life of the truck.
 

knuckle47

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From the list of services on the page, it seems like the shop has the capability to have done the complete head. Maybe the machinist was behind are started the job at 4pm. @Malleus looks at this like I do, it‘s open and it is all apart and accessible.

It’s not like changing a tire or sparkplugs…not really a big deal, you have easy access to a simple job On that stuff…..When it’s as much work re-assembling this component as you will be doing, I would get it done. Of course I won’t assume to be spending your money but I have wasted a lot of time and energy when I was younger so… I approach many things differently nowadays. Additionally you will know that you put a 100% effort into this project
 
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I know that everything costs something, but I'm struggling to understand how someone could be convinced to allow a machine shop to cut a head when it was assembled. How could you possibly know, before you cut it, that the head would clean up below the valves? How could a "reputable" shop guarantee that no valve damage would occur from their handling?

At the very least, the head should have disassembled and cleaned, because this is the only opportunity you have to do that. And it makes a difference.

Maybe I'm missing something.

In response to the OP's first post:
a) your head is fine; at most, you need to have the valves trimmed to match the material removed from the bottom face.
b) I would never reinstall a head without at least cleaning the carbon off the valves and seats and then checking for seals on every valve. These aren't V8s where you can remove a head without removing anything but a valve cover.

FWIW, you can't replace a valve stem; you have to replace the entire valve and then they have to be, at least, lapped into the seats.

Why would you go through all that work again, and again, after you'd done it once? Unless the head had recently been rebuilt/reconditioned, and in that case, there should be no reason to have the head off, unless there was a bottom or front end problem that wasn't caught when it was off the first time, the head shouldn't "need" to be removed but once or twice, at most, in the life of the truck.

There is some lack of knowledge on my part, this is the first engine I've torn apart and I thought it was a little weird that the shop was ok with just resurfacing. OTRAMM and NKP Garage on YouTube seemed thorough, and honestly with my lack of knowledge I trusted the shop to do what was right.
I mentioned this on another thread, but forgot to include that I had no head gasket issues before taking it apart. I was replacing my timing cover and I mangled up the head gasket on the front of the engine where the TC and Head meet and wasn't able to bend it back flat. maybe this is why the shop is recommending what he is recommending? not saying the shop is right, but even a Toyota master mechanic (older gentleman) at the dealership said he wouldn't do it even if it was his personal rig.

I'm a total noob but i am getting mixed opinions on people on mud (who know more than me) as well as the shop + mechanics.
 
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I would have had the shop do the valve seals, and valves. No point having to pull it again, wasn’t burning any oil at all? I would port and polish it too.
 

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