Phreakish
Well-Known Member
My main point wasn't the engine in the article but the treatment, don't know much about it 1st time hearing about it, looks like it cost $600 for the block and $1000 for the whole engine but if does gain 30-40% strength probably worth it for a 550 plus hp motor.
30-40% is a pretty optimistic estimate.
It's possible to see those kinds of gains with certain materials, but it's a method used to accelerate the aging process of metals. Cast iron gains strength over time, anywhere from 5-15% over about 30 years. Cryo can accelerate that, but I would be surprised to see yeild strength increase much more than 20%.
It is quite possible to increase the fatigue resistance though, but it's not accurate to call an increase in fatigue resistance an increase in strength.
Still, it's a good process. I've used it for stress relief and over aging of aluminum forgings with quite a bit of success. Some parts would move .050-.100" over 6" when machined. After Cryo, they don't move. Grain size is often increased, which also helped with stress corrosion cracking. Strangely, it made the material softer in a brinekl test, but ultimate strength increased about 8% on average.
Problem is, it takes a very good metallurgist to come up with a good treatment. It's not a matter of dunking in liquid nitrogen and waiting. There are specific steps required which yeild the right grains and microstructure. Small changes in casting composition could make it a pointless endeavor, and so I'd want to see demonstrated success on a similar block before cutting anyone a check.