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<veeduber@isp.com> wrote in message
news:1153893942.214648.74360@m79g2000cwm.googlegroups.com...
>
> Ernest Christley wrote:
> >
> > I have got an experimental engine, with an experimental cooling setup. Do
> > know for guaranteed that the cooling will be sufficient, so I will be
> > keeping a close eye on the water and oil temperatures. But the coatings
> > will cause more heat to be dumped into both.
> >-------------------------------------------------------------------------
>
> I do not understand the above. TBC's applied to the combustion chamber,
> piston crown, valve heads and the exhaust port, tend to reduce the
> waste heat that appears in the cooling system while increasing the
> waste heat that appears in the exhaust. This is based on comments from
> people running turbos who take a particular interest in the exhaust gas
> temps and how much energy they can recover from that source.
>
> --------------------------------------------------------------------------
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>
> > How would a typical
> > homebuilder know the difference between elevated temps due to a more
> > efficient heat transfer and inadequate cooling?
>
> --------------------------------------------------------------------------
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>
> I do not know.
>
> --------------------------------------------------------------------------
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>
> > Then there is the issue of what the redline temperatures are set for.
> > In the rotary, it is for the main bearings. Would the barriers and
> > dispersants change the thermal characteristics in such a way that the
> > temps readings taking in the normal places look adequate, but in reality
> > critical parts are being fried?
>
> --------------------------------------------------------------------------
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>
> I do not know.
>
> My only direct, personal experience with coatings has been with air
> cooled engines. I began experimenting with Tech-Line's coatings in
> 2001, using a 6cid lawn-mower engine as my test bed. Most of my time
> was spent learning how to apply the stuff. Once I was reasonably sure
> of I was applying the coatings correctly I began trying to quantify the
> benefit, if any. It took about a year to figure out affordable methods
> of measuring temperature & torque.
>
> About the best I can say is that I saw some improvement, and that the
> coatings proved to be durable. On that basis I went ahead and
> assembled a stock VW engine from used (but coated) parts, intending to
> run it for several hundred hours, tearing it down periodically.
> Unfortunately, when gasoline went above $2/gal I could no longer afford
> the luxury of my experiments. At that time the stock engine had
> accumulated about 75 hrs and was a perfect null, experimentally, in
> that it showed absolutely no signs of wear or deterioration of the
> coating(s).
>
> My experiments with TLTD (the thermal disbursant) involved heating
> coated and uncoated coupons of cast aluminum and mild steel with the
> element from a 100W. soldering iron and plotting their temperature
> (convection and conduction) against time.
>
> My goal was to explore possible solutions to well known problems seen
> in high-out engines based on VW after-market components. Despite being
> unable to complete the full series of tests on the stock engine, I've
> sufficient confidence in the coatings to apply them to several other
> engines, all of higher output, which I am in the process of doing. But
> with gas now over $3 and still rising there's a good chance I won't be
> able to afford running-in the completed engines, let alone fly behind
> them.
>
> I resorted to experiments because Tech-Line could not offer any advice
> regarding the use of their coatings on air cooled engines. They did
> refer me to a couple of coating shops but their claims were a bit
> extravagant and they were unwilling to put me in touch with any of
> their air cooled customers. Since you are dealing with a water-cooled
> engine, perhaps you'll have better luck.
>
> -R.S.Hoover
>
Interestingly, this series of postings came alone currently with a friend
attempting to introduce me to a network marketed product which claims to
gradually coat the piston tops, spark plugs, valves, and "fire deck" (which
is their name for the surface of the head inside the combustion chamber) of
an engine with a "sacrificial catalyst". My two semesters of college
chemistry caused me to dismiss that description is self contradictory (i.e.
Bunk!); however, I'm willing to accept a description such as "continuously
deposited ablative thermal barrier coating".
What makes all of that interesting (to me) is that the manufacturer's claim
equates to 9% to 10% improvement in torque with the same fuel burn, or an
approximate 10% inprovement in fuel consumption. If their theory is
correct, and my recollection of Boyle's Gas Law and of the Karnot Cycle
suggests that it is, then the much more durable Tech-Line Thermal Barrier
coating should have a similar result.
I'm quite curious whether your results to date pointed in the same
direction.
Peter Dohm
P.S.: There "aint no free lunch" so I'd presume that the overall heat
retained in the engine would be a little less for a given output; but that a
little more heat might be conducted back to the exhaust port area of the
head from the exhaust tubing. I've no idea how much of a problem that
might be on some engines.
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Re: Veedubber's Tech-Line Coatings
