[hurryinhoosier62]

Originally Posted by steve25

Any one have Jim Hands book to post up how much abuse a 455 crank took that he has fail that he talks about?

I will do so later if no one else does, but the amount of time it took of getting beat on was astounding before it gave out!

With lighter reciprocal parts getting use in builds these days I would say 650 is where I would draw the line in being very safe as long as your not planning to race the motor every weekend for 2 seasons.

Prepping the crank ( polishing the crap out of it) will make a huge difference in longevity as will cryogenic treatment if theres a location close enough to drive it to.

Tuning for no detonation I am considering a given.

The SD455 acording to the engineer who designed it was made to run day and night at 6000 rpm with a good margin of safety, and these motors left the the factory with a cast crank, so just putting that out there.

Steve, I am glad people are finally discovering the cost effective nature of cryo treating engine components. We here in IN are blessed to have Indy Cryo in Indy. Nitriding is another process I recommend.

[Dragncar]

Originally Posted by i82much

so how much stronger is a $700 aftermarket forging vs a factory N?

A lot. Kinsler had a Scat 4340 crank at around 1500 HP for years.
A PMD cast crank would have been in pieces.
Jim Butler told me on their old school N02 engines they had the 455 N cranks for 100 passes and threw them away.
They were not making anywhere close to 1500HP back then.

[PAUL K]

Originally Posted by Dragncar

A lot. Kinsler had a Scat 4340 crank at around 1500 HP for years.
A PMD cast crank would have been in pieces.
Jim Butler told me on their old school N02 engines they had the 455 N cranks for 100 passes and threw them away.
They were not making anywhere close to 1500HP back then.

Isn't that the same source that told you SD 455 rod crack if you look at them right?

Let's review the facts;

The guy that has the sole rights and a garage full (literally) of new aftermarket cast crankshafts says the factory cranks suck.

The guy that has the deep deal on aftermarket rods, says the best factory forged rods suck.

Things that make you go hmmmm


Also I doubt you know how much prep work has been done to KK's crankshaft. I'm willing to bet SCAT wouldn't recognize it as one of their own upon an initial visual inspection.

[PAUL K]

Originally Posted by i82much

so how much stronger is a $700 aftermarket forging vs a factory N?

Are there anymore $700 forgings?

The issue with the forgings is quality control. A lot of them require work and some are hard to balance. Every once in a while you get a bad one that breaks apart. However with the dwindling supply of factory castings I'm glad we have the option.

At the level most Pontiac are built, the end user will gain nothing but a false sense of assurance that their aftermarket crank is better than a good factory crankshaft.... And they can say they have a "stroker" ..... Or are a stroker as you're thinking right now

[HWYSTR455]

I tossed a 421 forged rod in a 455, but it was around 200k miles of abuse, it windowed the block. Aftermarket ones weren't readily available or affordable at that time.

I had a 455 crank break right in front of the #2 main, but I suspect it MIGHT have been caused by a balancer problem. That build had about 90k or so abusive miles on it best I can recall (without checking notes).

Pretty sure I posted pics of the crank here.

It's not worth the risk to run a factory crank anymore for a new build these days, the cost for piece of mind is worth knowing.


.

[i82much]

Originally Posted by PAUL K

Are there anymore $700 forgings?

apparently not! wow, things have gone up. i just checked and an IA2 block is 4500 now! i could swear mine was 2500 or so when i bought mine but that was almost 20 years ago. Time flies!

[performerrpm]

Originally Posted by i82much

apparently not! wow, things have gone up. i just checked and an IA2 block is 4500 now! i could swear mine was 2500 or so when i bought mine but that was almost 20 years ago. Time flies!

RPM still has 700 dollar cranks. i got one of their 4 375 cranks for 550 or 600 shipped. then it went to 700.


i bought my IA2 last march for 3900. i checked right at the end of the year when i was thinking of getting one more and they were 4500...

[hurryinhoosier62]

Originally Posted by performerrpm

RPM still has 700 dollar cranks. i got one of their 4 375 cranks for 550 or 600 shipped. then it went to 700.


i bought my IA2 last march for 3900. i checked right at the end of the year when i was thinking of getting one more and they were 4500...

How much taper in the journals? How far out of stroke is it. I haven’t seen anything from RPM that didn’t need rework to be useable.

[HWYSTR455]

Dang, 3900, that's good. As broke as I was around that time I probably would have still bought one.

I think I'm going to wait until the steel plants in the states get hot again and then buy one. That last OE block I have built would eventually like to replace, so have time.



.

[performerrpm]

Originally Posted by HWYSTR455

Dang, 3900, that's good. As broke as I was around that time I probably would have still bought one.

I think I'm going to wait until the steel plants in the states get hot again and then buy one. That last OE block I have built would eventually like to replace, so have time.



.

i still plan to get 1 more but ive got several original blocks i want to put together, plus even though i try to find deals for the oe blocks internals, i really dont wanna cheap out on the ia2 build....so ill prolly be eatin pg&j sandwiches awhile putting it together lol

[performerrpm]

Originally Posted by hurryinhoosier62

How much taper in the journals? How far out of stroke is it. I haven’t seen anything from RPM that didn’t need rework to be useable.

thats a damn good question lol....i guessi will find out soon enough. i havent used any of the 3 cranks i have yet.

i have an eagle 4.25 that i hope is not gonna need rework, and then i have the 2 RPM cranks, 4" and 4.375" i only gave 500 for the 4" so hopefully i atleast break even getting whatever needs done to make it useable.


whats ur take on the eagles?