Both a 4G64 and a 4G63 would be great to get hard data on.

 

wishful thinking. they are not. I have way more information than I have time to share. I took cranks in for hardness testing as well. different results to that guy in germany. have left cranks outside hardened and unhardened . unhardened was completely orange after about two weeks. hardened can sit outside for a couple months before rust appears significant. I really think stuff gets made up on the Internet just to win arguments.

I have personally ruined a dozen 7 bolt engines from low oil pressure or excessive knock leading to rod knock. all dozen engines needed the crank replaced. doesnt matter how small the knock sound is. once its audible the journal is no longer round.

conversely with hardened cranks. I have driven them with knock noise for weeks. then simply dropped pan for new bearings. then drove for years. there is really no comparing the difference . one is durable one is not.

 

these bearing shells show the value of hardened cranks. I built an engine for a customer with a nitrided 7 bolt crank. on his first oil change he jacked car up on the oil pan. the oil pickup was severely restricted. he drove car for two weeks before he wanted me to fix the rod knock. oil pressure would not go over 30psi when car came in. I dropped oil pan and installed new bearings. engine ran great.

 

Would you mind providing a little more details/context to what you are saying here? Knowing nothing about you or your work this just comes off as you being a horrible engine builder putting forth purely anecdotal evidence. Im sure that was not your intention so a little more detail might help to clarify.

 

Someone smashing the oil pan into the pick up doesn't make him a horrible engine builder.

 

well im sure he isn't, i was just commenting thats how it came across, and it was the more of him personally ruining a dozen engines part that came across kinda iffy.

 

I think that was more of a "years of trial and error" comment as opposed to "I'm a poor builder who keeps blowing these things up."

 

yah thats what i was thinking too, but without any context it can come across as "I have built so many of these engines that the dozen failures i have seen have lead me to x conclusions" but without more context it could also come across as "I've blown up a dozen engines so i know what im talking about". I just thought i would point that out because to random person reading this like me it isn't obviously clear which it is.

 

I have a thrashed evo 8 crank I'd be willing to send off in the name of science.

 

Why would they choose not to harden it? Cost savings?

 

yup..

 

Well, we are not sure they did.

Back in the sixties engines became more and more powerful. This required the design and metals they were made of to be beefed up considerably. Then along came emissions, low compression ratios and small valves. Suddenly, twenty years later it was group think in the industry - why are we making engines so strong? The funny thing about it, by this time they were starting to make engines powerful again.

This group think is what hatched the seven bolt 4g63. And if you know the history you know that many of them failed in normal use. Since then it has been a process of fixing and refining the engine and this took years. If crank hardening did go away this would be part of the seven bolt engine change.

 

most of this experimental crap was done for my own knowledge. started playing with the 4g63 in the early 90s. bought and sold a lot of cars. fixed them as cheap as possible. led the way in modifying cars in tampa. problem is tampa is not money. its more mexican. everyone does it on the cheap here. do it cheap and you are doing it twice.

 

thanks for that I know exactly what you are talking about, these same people will complain even after exactly what you warned them would happen does.