You learn something new everyday. How long will an LA small block hold up at 550 horsepower
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.
