cryo freezing?

2000aleroff · 10-28-2009, 12:43 AM

so obviously forged internals on the 3400 is mostly limited to pistons. so i was thinking about cryo freezing the crank. anyone done this? know how much it cost haha?

Recommended or not?
im still researching it but i know someone on here knows about it..

Cliff8928 · 10-28-2009, 01:51 AM

You can use a crank from a 3500 which were forged for a limited production.

Blktrax · 10-28-2009, 07:56 AM

Anything is possible for a price, and really for anything than a dedicated race car it appears cost prohibitive.

One example:
http://www.nwcryo.com/motorsports.html
http://www.nwcryo.com/motorsports_price.html

I would say the biggest issue, with cryo treating, is the base part you start with. If its not new and has any kind of microscopic cracking or fault in the casting like large air pockets, the cryotreating because it changes the metal can cause it to fail in the process or after reassembly.

Magnaflux engine part inspection before cryotreating.
http://www.jandm-machine.com/magnaflux.html

But really all it is great for a massivly built motor, but for a DD street machine all thats gonna be a lot in labor and materials, for a bottom end that can hold up to a lot stock.

2000aleroff · 10-28-2009, 12:45 PM

thats exactly what i wanted blktrax, thanks. and i heard you can used a 3500 crank but you have to machine it a lot to fit. and its not like im going to be running 20 psi or anything, i would just like some reassurance that it wont snap when im running 7-10 psi

Blktrax · 10-28-2009, 12:53 PM

Nothings 100%, there souldnt be any reason you cant. But detonation will end it quick, just feed it enough fuel.

kwhauck · 10-28-2009, 04:20 PM

With proper tuning you shouldn't have to touch your bottem end at all running 7-10 psi.

That being said if you are serious about pushing the limits, and just want a little feel good, the crank can be left alone. Forged pistons are a great idea. The rods are fine too, but i opted for some narrowed sbc forged 800hp scat rods, just to make sure. I considered using a 3500 crank for awhile and actually have two of the forged ones in my garage. The 3500 crank will drop right in as the main bearing are the same, the big difference is the rod journal bearings. When i was doing my research I decided that the $150 in machining, $150 in cryo, plus the $200 for an ECT to run the 3500 crank it wasn't worth it to me, so I am taking my chances at 500+hp on a stock crank. If it does fail (which i highly doubt) i have 2 forged 3500s and may look into it. If you are getting new rods, you may be able to find a 5.7 rod with a 2.2. journal end to fit our engines, but i opted to use the 3400 crank so I didn't look.

Cryo-hardening is great and yes it's a little costly but you gotta pay to play and i do things right the first time. My entire 5-speed gearbox has been cryotreated........

2000aleroff · 11-26-2009, 04:47 AM

so if i were to go with forged rods, scat 5.7 and a 2.2 journal. what beam? and what do you mean narrowed?

kwhauck · 11-26-2009, 01:15 PM

on our motors there is a main in between each rod, on a sbc motor, they have two rods up against each other. When they do this one side of the rod is wider than the other, i have the specs listed somewhere. I'll try to find them....