cautionary tale

Greg > wrote in :

> Tegger wrote:
>
>>
>> I do my valves once a year, which equates to about 25,000 miles. I
>> find perhaps one or two that have moved maybe a thou. Some years
>> there's no noticeable change to any of them. I suspect this valve
>> came from an engine that may have NEVER had its valved checked.
>
> Yea. I check my Accord once a year, more out of guilt than anything
> else. I don't expect to find that anything has moved more than a
> thou.
>
> Even with zero maintenance, you're got to wonder if they abused the
> engine somehow. Assuming the valves were set correctly at some time,
> it takes a lot of seat wear to eat up the clearance. (Right?)




I think it also has a lot to do with oil change intervals. The engine in
question may have had an inadequate frequency of oil changes.


--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

Tegger wrote:

>> Even with zero maintenance, you're got to wonder if they abused the
>> engine somehow. Assuming the valves were set correctly at some time,
>> it takes a lot of seat wear to eat up the clearance. (Right?)

> I think it also has a lot to do with oil change intervals. The engine in
> question may have had an inadequate frequency of oil changes.

That was my first thought, that the owner had run some additive-free,
buck-a-quart, SA rated oil, or hadn't bothered to change it at all. But
in that case, it seems you'd expect accelerated cam lobe wear that would
tend to open the lash clearance, if anything.

Does the minuscule volume of blow-by oil aid valve seat lubrication in
any way?

Regarding the original picture, I've got to agree with Jim, that lots of
high RPM and/or heat has worn or peened the valve to death. I'd like to
see pics of the seats too.

> I haven't seen a valve that bad since my brother in law pulled in the
> driveway with his Fiat just barely able to make it up hills in the early
> 80's.

Hey I resemble that remark, sold off my 1971 Fiat circa 1979
in just about that state! Replacedit for with Alfa and drove it until it
ate a (sodium-filled) valve about eight years later.

So far, in my experience, Hondas don't do that!

J.

On 12/06/2009 04:41 PM, Greg wrote:
> Tegger wrote:
>
>>> Even with zero maintenance, you're got to wonder if they abused the
>>> engine somehow. Assuming the valves were set correctly at some time,
>>> it takes a lot of seat wear to eat up the clearance. (Right?)
>
>> I think it also has a lot to do with oil change intervals. The engine
>> in question may have had an inadequate frequency of oil changes.
>
> That was my first thought, that the owner had run some additive-free,
> buck-a-quart, SA rated oil, or hadn't bothered to change it at all. But
> in that case, it seems you'd expect accelerated cam lobe wear that would
> tend to open the lash clearance, if anything.
>
> Does the minuscule volume of blow-by oil aid valve seat lubrication in
> any way?
>
> Regarding the original picture, I've got to agree with Jim, that lots of
> high RPM and/or heat has worn or peened the valve to death. I'd like to
> see pics of the seats too.

the seats are fine.

the damage you see is not just heat [and definitely not peening], but
actual hot gas erosion. if you've ever used an oxy-acetylene cutting
torch, you'll have created gouges like this in the steel you cut, only
on a larger scale.

bottom line, there are actually two potential causes of this:

1. insufficient valve lash causing leakage, heating and then erosion.

2. defect in the valve - a "soft spot" could start the leakage, and
erosion takes hold from there.

#1 is completely avoidable.

On 12/06/2009 12:54 PM, Tegger wrote:
> jim > wrote in
> :
>
>> On 12/06/2009 05:37 AM, Tegger wrote:
>>>
>>> I suspect this valve
>>> came fom an engine that may have NEVER had its valved checked.
>>
>>
>> i suspect it was done, but done badly. should leave the feeler gauge
>> in when snugging up the lock nut so the adjuster doesn't move.
>>
>
>
> I suppose you could do it that way, but I've been doing valves for almost
> 30 years and have never left the gauge in.
>
> All I do is to make careful note of the position of the screwdriver slot at
> the correct clearance setting, and make a tiny adjustment down to allow for
> the slight gain in clearance you get when you snug the nut again.
>
>

well, provided the locking nuts are not crudded up, you can leave the
gauge in and the adjuster won't turn as you tighten the lock nut. makes
it a quick one-handed operation. if there's crud in the threads, you
need the screwdriver and two hands as you say.

jim beam > wrote in
t:

> On 12/06/2009 12:54 PM, Tegger wrote:
>> jim > wrote in
>> :
>>
>>> On 12/06/2009 05:37 AM, Tegger wrote:
>>>>
>>>> I suspect this valve
>>>> came fom an engine that may have NEVER had its valved checked.
>>>
>>>
>>> i suspect it was done, but done badly. should leave the feeler
>>> gauge in when snugging up the lock nut so the adjuster doesn't move.
>>>
>>
>>
>> I suppose you could do it that way, but I've been doing valves for
>> almost 30 years and have never left the gauge in.
>>
>> All I do is to make careful note of the position of the screwdriver
>> slot at the correct clearance setting, and make a tiny adjustment
>> down to allow for the slight gain in clearance you get when you snug
>> the nut again.
>>
>>
>
> well, provided the locking nuts are not crudded up, you can leave the
> gauge in and the adjuster won't turn as you tighten the lock nut.
> makes it a quick one-handed operation. if there's crud in the
> threads, you need the screwdriver and two hands as you say.
>
>



My valve mechanism is squeaky-clean, with hardly any varnish, let alone
crud. I cannot tighten the locknuts without holding the screwdriver still,
otherwise the adjuster attempts to turn, even with a gauge in the way.
You're putting 18ft/lbs of torque on that locknut, which is sufficient to
push a lot of things around.


--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

On 12/08/2009 05:21 AM, Tegger wrote:
> jim > wrote in
> t:
>
>> On 12/06/2009 12:54 PM, Tegger wrote:
>>> jim > wrote in
>>> :
>>>
>>>> On 12/06/2009 05:37 AM, Tegger wrote:
>>>>>
>>>>> I suspect this valve
>>>>> came fom an engine that may have NEVER had its valved checked.
>>>>
>>>>
>>>> i suspect it was done, but done badly. should leave the feeler
>>>> gauge in when snugging up the lock nut so the adjuster doesn't move.
>>>>
>>>
>>>
>>> I suppose you could do it that way, but I've been doing valves for
>>> almost 30 years and have never left the gauge in.
>>>
>>> All I do is to make careful note of the position of the screwdriver
>>> slot at the correct clearance setting, and make a tiny adjustment
>>> down to allow for the slight gain in clearance you get when you snug
>>> the nut again.
>>>
>>>
>>
>> well, provided the locking nuts are not crudded up, you can leave the
>> gauge in and the adjuster won't turn as you tighten the lock nut.
>> makes it a quick one-handed operation. if there's crud in the
>> threads, you need the screwdriver and two hands as you say.
>>
>>
>
>
>
> My valve mechanism is squeaky-clean, with hardly any varnish, let alone
> crud. I cannot tighten the locknuts without holding the screwdriver still,
> otherwise the adjuster attempts to turn, even with a gauge in the way.
> You're putting 18ft/lbs of torque on that locknut, which is sufficient to
> push a lot of things around.
>
>
my daily d15 is clean also, and the adjusters stay put as described.
the patient in the valve surgery case however, is crudded up, and a
screwdriver is essential.

Thus spake Tegger > :

>"Elmo P. Shagnasty" > wrote in
:
>
>> In article m>,
>> Nasty > wrote:
>>
>>> OK. Now you guys have ruined my quiet Sunday morning. Are you saying
>>> that valves should be or MUST be checked on a scheduled basis? Even
>>> when there are no other indications of a valve related problem?
>>>
>>> I have 145K on my 2000 Accord that runs smooth as silk. Should I take
>>> it in "just because"?
>>
>> The 2000 Accord owner's manual specifies valve adjustment every so
>> many miles. At one time it was 15K miles, but I think yours is 30K
>> miles. That is, if it's a 4 cylinder.
>>
>> My 02 Odyssey specifies to do it "as needed if you hear noise".
>> That's marketing speak for "my God, it costs $300 to adjust valves on
>> this silly thing! We can't tell them to do THAT every 30K miles!"
>
>
>
>That's also kind of silly (to my mind) because it's REDUCED valve
>clearances that do the big damage. You can't hear reduced clearances.

Sure you can. It's that little "tink tink tink" sound of broken metal
bouncing around inside the cylinder.
--

- dillon I am not invalid

I love my country, It's my government I fear.

Hey, turnabout's fair play.

Thus spake jim beam > :

>On 12/06/2009 05:37 AM, Tegger wrote:
>> jim > wrote in
>> t:
>>
>>> http://www.flickr.com/photos/38636024@N00/4162355180/
>>>
>>> when is the last time you checked /your/ valve lash? don't you want to
>>> avoid this little problem?
>>>
>>> just pulled this from a civic with "an emissions problem". the
>>> incredible doofus that was ripping the owner off trying to "fix" the
>>> problem, simply welded in a second HUGE catalyst into the exhaust
>>> system. and was disappointed when it didn't work! then they removed
>>> the bulb from the "check engine" light...
>>>
>>>
>>
>>
>> Wow! Nobody noticed the lumpy idle?
>
>d15b1 motor - unlike almost all other honda motors, the flywheel is
>/really/ heavy - it idled reasonably well. they should have noticed the
>lack of difference that plug made when pulling the lead though. a
>compression test might have helped too.
>
>initially, i suspected a thrown rod, [classic for "smooth idle"
>misfires] but a long screwdriver down the spark plug hole showed the
>piston still moving.

You said "thrown rod" and my years of drag racing tell me that usually
means a see-through block, or at least an invisible pan.

>
>
>>
>> I do my valves once a year, which equates to about 25,000 miles. I find
>> perhaps one or two that have moved maybe a thou. Some years there's no
>> noticeable change to any of them. I suspect this valve came fom an engine
>> that may have NEVER had its valved checked.
>
>i suspect it was done, but done badly. should leave the feeler gauge in
>when snugging up the lock nut so the adjuster doesn't move.
--

- dillon I am not invalid

I love my country, It's my government I fear.

Hey, turnabout's fair play.

On 12/11/2009 05:18 PM, Dillon Pyron wrote:
> Thus spake jim > :
>
>> On 12/06/2009 05:37 AM, Tegger wrote:
>>> jim > wrote in
>>> t:
>>>
>>>> http://www.flickr.com/photos/38636024@N00/4162355180/
>>>>
>>>> when is the last time you checked /your/ valve lash? don't you want to
>>>> avoid this little problem?
>>>>
>>>> just pulled this from a civic with "an emissions problem". the
>>>> incredible doofus that was ripping the owner off trying to "fix" the
>>>> problem, simply welded in a second HUGE catalyst into the exhaust
>>>> system. and was disappointed when it didn't work! then they removed
>>>> the bulb from the "check engine" light...
>>>>
>>>>
>>>
>>>
>>> Wow! Nobody noticed the lumpy idle?
>>
>> d15b1 motor - unlike almost all other honda motors, the flywheel is
>> /really/ heavy - it idled reasonably well. they should have noticed the
>> lack of difference that plug made when pulling the lead though. a
>> compression test might have helped too.
>>
>> initially, i suspected a thrown rod, [classic for "smooth idle"
>> misfires] but a long screwdriver down the spark plug hole showed the
>> piston still moving.
>
> You said "thrown rod" and my years of drag racing tell me that usually
> means a see-through block,

usually. but not always - depends how hard the motor was going when the
cap finally let go. i was looking at one in a junk yard just recently.
the head was off and there was no visible external damage to the
block, but one piston was out of phase and rotated. you don't get
/that/ with the rod still connected, regardless of holes.


> or at least an invisible pan.
>
>>
>>
>>>
>>> I do my valves once a year, which equates to about 25,000 miles. I find
>>> perhaps one or two that have moved maybe a thou. Some years there's no
>>> noticeable change to any of them. I suspect this valve came fom an engine
>>> that may have NEVER had its valved checked.
>>
>> i suspect it was done, but done badly. should leave the feeler gauge in
>> when snugging up the lock nut so the adjuster doesn't move.