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

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273 said:
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.
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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.
 
273 said:
In this build 747-770hp 376 was cryogenically treated and said to increase block strength 30-40%

376 cid Mopar Engine - Engine Builder Magazine
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OH NO!!!!!! That engine has a GIRDLE!!!!!
Cue the FABO Banana Splits!!!!
Quick, someone get some Donuts, so we don't have to hear about the dogshit!!!

Gooodle.jpg
 
273 said:
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.
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@Oldmanmopar has mentioned that type treatment before. He oughtta know. lol
 
see herb jr posting alot on facebook mopar threads and some times sounds like he knows what he's arguing about,..some times it seems he just arguing!
 
550 doesn't sound like much to me honestly... if it's built right and tuned right i can't see any reason the block would ever be an issue unless you bored it over 60 or so.. but i don't know much.
P.S. or did stupid **** with bad tuning of course..
 
I wondered where this was going, as mine makes 620 ish and has been raced every summer for 12+ years lol
 
It's 4 o'clock somewhere!! ♫♫♫♫♫♫♫♫
 
So Herb Sr is still alive and kicking. I saw them this past weekend at their museum here in Burlington NC. They are having an open house this coming weekend as well on Saturday.

Herb Jr can be a bit rough around the edges and a bit course at times, but he knows Mopar drag racing fairly well. His sons are very involved in the family business as well. They are still a drag racing family.

Everybody has their opinions and have seen and experiences different things. I’d listen to all sides and find the truth somewhere in the middle.
 
273 said:
In this build 747-770hp 376 was cryogenically treated and said to increase block strength 30-40%

376 cid Mopar Engine - Engine Builder Magazine
Click to expand...


I had a buddy that offered this service to me for free on afternoon shift back in the late 1970’s early 80’s. I didn’t know enough about it back then and although I was pretty quick for the times learned the boundaries. Our weaknesses back then were rods of course and big block Mopar cranks. The rods issues were handled by lowering the rpm and every rebuild on a big block I would start with a fresh crank. Running 9’s they always showed signs of cracking so after awhile I stopped getting them magnifluxed. We sent out out knives in the steel mill that cut hot and cold steel to get treated and it helped a lot.
 
pittsburghracer said:
I guarantee you more that 100 passes unless you are a half-azzed engine builder. I wonder if Daddy thought that way. Lol
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Herb sr. has accomplished more in drag racing than everyone on this board combined. His accomplishments speak for themselves and he doesn't have to get on the internet and thump his chest.
 
justinp61 said:
Herb sr. has accomplished more in drag racing than everyone on this board combined. His accomplishments speak for themselves and he doesn't have to get on the internet and thump his chest.
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He sure doesn't !!!!!!!
He's obviously got you to do that for him!!!
:popcorn:
 
If tuned right and decent parts used you should wear the block out before you break it at the 550HP IMO. A lot of keyboard warriors on Facebook and other sites. Add in the ones who dyno'd their motors but the ET slips aren't even close to what it dyno'd.
 
My brothers split a cylinder only bored .040" 360 stroker about 460hp but the block was questionable from ATK.
 
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