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New valve would require full cylinder head valve seat machining process?

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YOUR RESEARCHNew valve would require full cylinder head valve seat machining process?

Leading reported evidence

Check dimension in the overhaul book), there's no reason

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Suggestion
Unless the valve stems are bent, or the edges of the valves are worn too thin (check the dimension in the overhaul book), there's no reason to replace valves.
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New valve would require full cylinder head valve seat machining process?

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Leading evidence: 'Check dimension in the overhaul book), there's no reason' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check dimension in the overhaul book), there's no reason' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.

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Check valves

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Suggestion
After lapping the valves drop them into place without springs, turn the head so the combustion chamber is on top, and pour some denatured alcohol in to check the valves for leaks.
Original post Read captured discussion
New valve would require full cylinder head valve seat machining process?

Replace valves

Suggestion or failed attempt

No successful repair reported for this finding.

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Reported fixes: 0
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Suggestion
Unless the valve stems are bent, or the edges of the valves are worn too thin (check the dimension in the overhaul book), there's no reason to replace valves.
Original post Read captured discussion
New valve would require full cylinder head valve seat machining process?

Frequently discussed actions (3)

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Check dimension in the overhaul book), there's no reason

No successful repair reported for this finding.

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Reported fixes: 0
Unsuccessful attempts: 1
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Read evidence and context

Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

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Suggestion
Unless the valve stems are bent, or the edges of the valves are worn too thin (check the dimension in the overhaul book), there's no reason to replace valves.
Original post Read captured discussion
New valve would require full cylinder head valve seat machining process?

Check valves

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion
After lapping the valves drop them into place without springs, turn the head so the combustion chamber is on top, and pour some denatured alcohol in to check the valves for leaks.
Original post Read captured discussion
New valve would require full cylinder head valve seat machining process?

Replace valves

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion
Unless the valve stems are bent, or the edges of the valves are worn too thin (check the dimension in the overhaul book), there's no reason to replace valves.
Original post Read captured discussion
New valve would require full cylinder head valve seat machining process?

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POST 1 / ORIGINAL POSTEROriginal post

Not for an immediate need but out of curiosity. I know it depends on the condition of the current cylinder head valve seat but in general if you were to replace you valves with a new ones would it require (always/most of the time) also full machining process also on the actually cylinder head. Or are those valves so close to perfect that with a short lapping you could reseat those properly. I'm just thinking that if it requires a lot of "lapping" it could "over process" that current good cylinder head valve seat.

POST 2Original post

The decider here is the width of the valve seat lands on the valve seats. If they are too wide there is not enough sealing force and the valves will end up not sealing. There should be a dimension in the overhaul book that states the maximum valve seat land width. If this is exceeded you may wish to have the valve seats ground. It is a bit of a judgement call depending on how the engine is to be used. Also note that these cast-in-place valve seats are not a trivial item to replace. If the valve seat width is OK, then lapping should be enough. After lapping the valves drop them into place without springs, turn the head so the combustion chamber is on top, and pour some denatured alcohol in to check the valves for leaks. Unless the valve stems are bent, or the edges of the valves are worn too thin (check the dimension in the overhaul book), there's no reason to replace valves.

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