cryogenically freeze my engine?

[fordperson]

Hey, Im planning on cryo-ing my engine @ 300below.com its 560$ to cryo the whole engine/turbo... I was wondering if anyone had any experiences with the cryo process or are there any studies done on this subject?

I mainly want to increase strength and durability of the engine components. The main focus of the cryo would be the block/crankshaft but since the price for the block+crank is almost the same as for the whole engine why not...

Another consern I have is, the parts that I already bought like the arrow rods,cp pistons are pretty strong, could the cryo actually make it weaker?

Tom

[MagicRat]

It depends on how the cryo freezing is done. The idea is to 'stress relieve' the cast components by gradually reducing the temp them increasing it.
I suspect it takes many hours of gradual cooling then warming to do this. If this was done quickly, you would just simply amplify the existing internal stresses.

Engines actually get stress relieved every time you drive your car. All the engine parts are heated then gradually cooled when you switch the engine off.
Lots of engine builders know than 'seasoned' or used cast components frequently are stronger than new ones.

However, there are other, proven ways to stress relieve components, such as shot peening.

Benefits of Shot Peening:

Compressive Stresses
Cold Working

Shot Peening increases resistance to
……fatigue failure
…corrosion fatigue
…hydrogen assisted cracking
…cavitation erosion
…stress corrosion cracking
…galling
…fretting

Shot Peening Helps with
……surface texturing
…intergranular corrosion resistance
…closing of porosity
…testing of bond coatings
…work hardening
…increased strength
…increased durability


Although the process of Shot Peening has evolved and become very technical, it still employs the age-old principles of pre-stressing and work-hardening a material to create a harder and more durable material.

Today, Shot Peening involves bombarding a material with small spherical media called shot. Each piece of shot is the modern day version of the hammer/ stone used in the past. As the Shot Peening is performed, the atoms on the surface of the metal become crowded and try to restore the metal's original shape by pushing outward. This pulls, towards the surface, the atoms in the deeper layers, which resist the outward pull, thereby creating internal tensile stress that keeps the part in equilibrium with the compressive stress on the surface. The tensile stresses, resulting from Shot Peening, deep in the part are not as problematic as tensile stresses on the surface because cracks are less likely to start on the interior.

[TheSilentChamber]

The stuff I'v read on cryogenic stuff (as for brake applications) the stuff is rapidly frozen, then slowly braught back up to room temp over a matter of several hours. This is done to alter the grain structure of the metal (basically what magic rat said)

[curtis73]

Cryogenics will add hardness, but that is not always helpful. Things like blocks, cranks, rods, and heads take serious abuse that is absorbed by softer castings. Things like ball bearing surfaces, brake rotors, journals, and lifters can benefit from hardening of some sort, but in general I think hardening engines is not a wise choice unless its a low-rpm application. Cadillac used extremely high nickel content in their castings to make it rock hard. It helped out with cylinder wear and overall longevity, but did nothing for dampening vibrations. The Caddy engines were such low RPM grunters that they didn't even use harmonic dampers on the crank, so hard casting was a smart idea.

Its the same idea behind using forged parts instead of cast. The casting is hard and brittle while forgings are stronger, but "softer". Each has its place, just make sure you have the right application.