ceramic pistons - discuss

On Fri, 19 Nov 2010 17:40:24 -0600, hls wrote:

> "Bret" > wrote in message
> ...
>> On Fri, 19 Nov 2010 16:39:26 -0600, hls wrote:
>>
>>> "Bret" > wrote in message
>>> ...
>>>> On Fri, 19 Nov 2010 09:07:44 -0800, jim beam wrote:
>>>>
>>>>> <http://blogs.dieselpowermag.com/6678899/diesel-engines/nr-ceramic-pistons/index.html>
>>>>
>>>> Gut reaction "Dodgy"
>>>
>>> I remember people like Smoky Yunick working on these long long ago.
>>> Technology has improved, but there are still some quirks about these
>>> things.
>>>
>>> I heard it said that ceramics are best used on engines that are used for
>>> long times at a set power level, and that the engine needs to be warmed
>>> completely before coming up to full operation.
>>
>> There are some sound principles involved, but the application of these
>> principles has prove difficult.
>> One reference to naked aluminium bores running with no rings, I have to
>> wonder about expansion coefficents
>
> Of course, expansion coefficients are an issue. "Naked aluminum bores"
> may not be totally naked. There is a world of technology out there to
> make things that are beyond the present horizon.
>
> I have always been interested in "metallizing". This technology is somewhat
> like electroplating, but the electrolyte bath is usually a fluoride flux.
> The base
> metal can be infused with metallic ions via this bath. The new metal
> actually
> penetrates and forms a surface alloy with the base metal. The possibilities
> are infinite.

I imagine the ceramic piston will match the bore at operating temp but will
be a mismatch when cold.I don't think micron sized wear coating will affect
the coefficent of expansion.
It's a well known problem with this tech.

On 11/20/2010 02:19 PM, Bret wrote:
> On Fri, 19 Nov 2010 17:40:24 -0600, hls wrote:
>
>> > wrote in message
>> ...
>>> On Fri, 19 Nov 2010 16:39:26 -0600, hls wrote:
>>>
>>>> > wrote in message
>>>> ...
>>>>> On Fri, 19 Nov 2010 09:07:44 -0800, jim beam wrote:
>>>>>
>>>>>> <http://blogs.dieselpowermag.com/6678899/diesel-engines/nr-ceramic-pistons/index.html>
>>>>>
>>>>> Gut reaction "Dodgy"
>>>>
>>>> I remember people like Smoky Yunick working on these long long ago.
>>>> Technology has improved, but there are still some quirks about these
>>>> things.
>>>>
>>>> I heard it said that ceramics are best used on engines that are used for
>>>> long times at a set power level, and that the engine needs to be warmed
>>>> completely before coming up to full operation.
>>>
>>> There are some sound principles involved, but the application of these
>>> principles has prove difficult.
>>> One reference to naked aluminium bores running with no rings, I have to
>>> wonder about expansion coefficents
>>
>> Of course, expansion coefficients are an issue. "Naked aluminum bores"
>> may not be totally naked. There is a world of technology out there to
>> make things that are beyond the present horizon.
>>
>> I have always been interested in "metallizing". This technology is somewhat
>> like electroplating, but the electrolyte bath is usually a fluoride flux.
>> The base
>> metal can be infused with metallic ions via this bath. The new metal
>> actually
>> penetrates and forms a surface alloy with the base metal. The possibilities
>> are infinite.
>
> I imagine the ceramic piston will match the bore at operating temp but will
> be a mismatch when cold.I don't think micron sized wear coating will affect
> the coefficent of expansion.
> It's a well known problem with this tech.

there's two types of "ceramic" - ceramic coatings, the ones you're
apparently thinking about, and full ceramic, where the whole component
is ceramic all the way through. it is the latter that has the benefits
of much reduced thermal expansion, lighter weight, and much better heat
resistance - per the original cite.

--
nomina rutrum rutrum

On Sun, 21 Nov 2010 11:50:20 -0800, jim beam wrote:

> On 11/20/2010 02:19 PM, Bret wrote:
>> On Fri, 19 Nov 2010 17:40:24 -0600, hls wrote:
>>
>>> > wrote in message
>>> ...
>>>> On Fri, 19 Nov 2010 16:39:26 -0600, hls wrote:
>>>>
>>>>> > wrote in message
>>>>> ...
>>>>>> On Fri, 19 Nov 2010 09:07:44 -0800, jim beam wrote:
>>>>>>
>>>>>>> <http://blogs.dieselpowermag.com/6678899/diesel-engines/nr-ceramic-pistons/index.html>
>>>>>>
>>>>>> Gut reaction "Dodgy"
>>>>>
>>>>> I remember people like Smoky Yunick working on these long long ago.
>>>>> Technology has improved, but there are still some quirks about these
>>>>> things.
>>>>>
>>>>> I heard it said that ceramics are best used on engines that are used for
>>>>> long times at a set power level, and that the engine needs to be warmed
>>>>> completely before coming up to full operation.
>>>>
>>>> There are some sound principles involved, but the application of these
>>>> principles has prove difficult.
>>>> One reference to naked aluminium bores running with no rings, I have to
>>>> wonder about expansion coefficents
>>>
>>> Of course, expansion coefficients are an issue. "Naked aluminum bores"
>>> may not be totally naked. There is a world of technology out there to
>>> make things that are beyond the present horizon.
>>>
>>> I have always been interested in "metallizing". This technology is somewhat
>>> like electroplating, but the electrolyte bath is usually a fluoride flux.
>>> The base
>>> metal can be infused with metallic ions via this bath. The new metal
>>> actually
>>> penetrates and forms a surface alloy with the base metal. The possibilities
>>> are infinite.
>>
>> I imagine the ceramic piston will match the bore at operating temp but will
>> be a mismatch when cold.I don't think micron sized wear coating will affect
>> the coefficent of expansion.
>> It's a well known problem with this tech.
>
> there's two types of "ceramic" - ceramic coatings, the ones you're
> apparently thinking about, and full ceramic, where the whole component
> is ceramic all the way through. it is the latter that has the benefits
> of much reduced thermal expansion, lighter weight, and much better heat
> resistance - per the original cite.

No, I am referring to the items in the OP.
A ceramic coated piston would presumably expand at the same rate as the
base material.
I don't think a solid ceramic piston would expand very much as you say.An
aluminium bore even if coated with a ceramic coating woul expand as per
aluminiums coefficent leaving the solid ceramic piston with no rings
flopping around

"Bret" > wrote in message news:115sevald1ni4> I imagine the
ceramic piston will match the bore at operating temp but will
> be a mismatch when cold.I don't think micron sized wear coating will
> affect
> the coefficent of expansion.
> It's a well known problem with this tech.

No, the plasma coating is for wear, and will not affect the c/e appreciably.
If it were very thick, it probably could not stand the expansion of the
cylinder bore.

"Bret" > wrote in message
.. .
>
> Hence the rings. I beleive the ceramic won't expand much under heating but
> the bore will.It seems to be a fine line they will be working to.

With all due regard for German technology, I have long ago lost my trust of
everything
new and exciting that is offered on the market, and would not be the first
to buy a set
of these (if I owned a vehicle which might benefit from them).

On Tue, 23 Nov 2010 07:28:10 -0600, hls wrote:

> "Bret" > wrote in message
> .. .
>>
>> Hence the rings. I beleive the ceramic won't expand much under heating but
>> the bore will.It seems to be a fine line they will be working to.
>
> With all due regard for German technology, I have long ago lost my trust of
> everything
> new and exciting that is offered on the market, and would not be the first
> to buy a set
> of these (if I owned a vehicle which might benefit from them).

Agreed, I'll wait until they are fitted from new.