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Re: Coatings to reduce operating temperatures

Posted: Sat Oct 14, 2017 12:57 pm
by bobrec1228
and aggressive oiling to keep it spinning free.
The largest possible oil cooler will greatly extend the run time of an "air-cooled" engine. Is that a possibility?
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A large oil cooler is in the works now, should be able to run a extra 2 qts of capacity with it!

Re: Coatings to reduce operating temperatures

Posted: Sat Oct 14, 2017 1:08 pm
by bobrec1228
roc wrote: Sat Oct 14, 2017 12:45 pm It seems wasteful to me to spend money in internal engine coating for an engine that will seize up.
Could you relocate the radiator to a more protected area, like in the trunk right behind the back seat?


Its only a waste of money if you dont enjoy it!
My engine doesn't bind-up since clearances have been opened up but it usually will diesel after a good hard run
And leave charred mess of oil to clean.... if im lucky

Re: Coatings to reduce operating temperatures

Posted: Sat Oct 14, 2017 4:07 pm
by BigBlockMopar
I recall a demo guy somewhere around Phoenix, Az used to like the Mopar 318 engines very much 'cause they would keep running the longest without water.

Re: Coatings to reduce operating temperatures

Posted: Sat Oct 14, 2017 7:05 pm
by stealth
Alky ...?

Re: Coatings to reduce operating temperatures

Posted: Sat Oct 14, 2017 9:07 pm
by MadBill
FWIW, an S/T search for thermal barrier coatings yields 272 hits...

Re: Coatings to reduce operating temperatures

Posted: Sat Oct 14, 2017 9:58 pm
by pamotorman
why not just a sealed block filled with water under 50 /75 PSIG ?? tack weld in the expansion plugs so they can't blow out. it would help keep it cool for a while and better and longer than no water

Re: Coatings to reduce operating temperatures

Posted: Sat Oct 14, 2017 10:19 pm
by Circlotron
Depending on the application, if there are times when only part throttle is needed, maybe you could then open the throttle fully and use a variable rev limiter to control rpm by shutting off the injectors preferably, or the spark at a pinch. That way the engine is ingesting the max amount of cool air and it will absorb heat from individual cylinders as it passes through on non-firing cycles. Similar in concept to what an OEM setup does in a gross overheat situation.

Re: Coatings to reduce operating temperatures

Posted: Sat Oct 14, 2017 10:33 pm
by Circlotron
joe 90 wrote: Sat Oct 14, 2017 2:40 am Like ceramic tiles on the space shuttle.
Got to be a couple of inches thick to insulate properly.
Don't forget the thin boundary layer of gases in a combustion chamber stops an aluminium piston from melting. Add a bit of detonation and the enormous extra turbulence this causes sweeps the boundary layer away. Then the piston melts and dies quick smart!

http://www.ktm950.info/how/Orange%20Gar ... n_101.html
"In addition, these pressure fronts (or shock waves) can sweep away the unburned boundary layer (see figure 2 above) of air-fuel mix near the metal surfaces in the combustion chamber. The boundary layer is a thin layer of fuel-air mix just above the metal surfaces of the combustion chamber (see figure 2, above). Physical principles (aptly called boundary conditions) require that under normal circumstances (i.e. equilibrium combustion, which means "nice, slow and thermally well transmitted") this boundary layer stays close to the metal surfaces. It usually is quite thin, maybe a fraction of a millimeter to a millimeter thick. This boundary layer will not burn even when reached by the flame front because it is in thermal contact with the cool metal, whose temperature is always well below the ignition temperature of the fuel-air mix. Only under the extreme conditions of detonation can this boundary layer be "swept away" by the high-pressure shock front that occurs during detonation. In that case, during these "far from equilibrium" process of the pressure-induced shock wave entering the boundary layer, the physical principles allured to above (the boundary conditions) will be effectively violated. The degree of violation will depend on (a) the pressure fluctuation caused by the shock front and (b) the adhesive and cohesive strength of the boundary layer. These boundary layers of air-fuel mix remain unburned during the normal combustion process due to their close proximity to the cool metal surfaces and act as an insulating layer and prevent a direct exposure of metal to the flame. Since pressure waves created during detonation can sweep away these unburned boundary layers of air-fuel mix, they leave parts of the piston top and combustion chamber exposed to the flame front. This, in turn, causes an immediate rise in the temperature of these parts, often leading to direct failure or at least to engine overheating."