Best filament for strength?

Bambu Filament and Accesories Filament
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I am currently designing a engine about the size of a weed whackers engine. I want to print it in something that can resist super high heat and super high pressures. Any recommendations?

I want to do something like this guy but with propane.
Youtube

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Don’t print it with plastic.

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Then what a carbon fiber reinforced nylon?

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Nylon is a plastic.

Specifying " super high heat and super high pressures" are relative terms with no engineering meaning. Search out and assign numerical values.

“Super high heat” does suggest that you plan to burn the propane, so compare typical temperatures of burning propane to the melting temperature of nylon.

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This data was readily found via Google.

Filament Best For Pros Cons Best Use
Nylon ( PA ) High strength & durability High tensile strength, impact-resistant, good chemical resistance Absorbs moisture, requires drying, difficult to print without an enclosure Small, high-strength pressure vessels
Polycarbonate (PC) High temperatures & impact resistance Extremely strong, heat-resistant (up to 150°C), impact-resistant High warping, requires a heated chamber High-pressure applications, moderate-temperature fluids
Carbon Fiber Reinforced (Nylon CF, PC CF) Strength-to-weight ratio High strength, reduced warping, lightweight Abrasive (requires hardened nozzle), brittle under high impact High-strength applications where weight is a concern
PEI (Ultem) Extreme conditions & professional use Aerospace-grade strength, chemical-resistant, high temperature resistance (~200°C) Expensive, requires an industrial printer High-pressure and high-temperature environments
PETG Moderate pressure & easy printing Easy to print, good chemical resistance, low moisture absorption Not as strong as PC or Nylon, prone to creep under load Low-pressure applications
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Screenshot 2025-01-28 180141
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Of the bambu filaments, as far as I know, the ppa-CF is the strongest, but this is very expensive and can only be printed on the X1E.
the second strongest is PAHT-CF, which is still very expensive for a 1kg roll, but is very stable for filament and can also be printed on other printers

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Well there are a couple of issues with that idea.

  1. Flame temperature of a stoichiometric Propane / Air combustion is close to 2000°C and there is no 3d Fdm printable polymer composite material that can withstand that.
  2. Heat conductivity of polymer materials is generally poor so you can’t conduct the heat on the internal combustion surface away fast enough to avoid rapid destruction.
  3. structural strength with heat usually declines very rapidly with polymers thus parts will blow out with the pressure & heat.
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