Originally posted by Y2K-SVT:
how strong are our engines cranks?????
i know that the svt crank is forged which means that for the most part its a durable unit. however under high power situatuations how strong is it??
also does the stock 2.5 use the same crank as the svt, also with the stroke being the same, what about the 3.0's with all the talk about titanium rods, sho bearings, and custom pistons. will the crank last in the long term
also has anyone thought of cryogenically (spelling) treating our existing componets, from what i understand it reorganises the componets structure and makes it stronger
what im looking to do is make a bad @$$ 3.0 with an 7500 rpm redline 8000 fuel cutoff but since i will only be able to afford this only once (with lots of penny pinching) i want it to be dead reliable
Cryogenic treatments in steels or iron alloys is mainly done to get rid of retained austenite. Austenite is one of the forms that steel takes when it is heated up. Quenching is then performed to transform the austenite to other phases such as martensite, bainite, etc. The problem is if not all austenite is transformed to another structure, then it will continue to slowly transform to other phases at a slow rate, even phases that are less desireable. The kinetics require long times at room temperature and above ranges. If you go to too high a temp then you begin to transform back into austenite. The kinetics are much faster for liquid N2 temperatures when transforming the retained austenite. As with all engineering it is more complicated than first glance.
As far as cryo treating other metals? It's basically virgin territory. There is evidence that it does nothing at all for aluminum alloys, but that could change any day since its not positive.
for what its worth: if you want to get cryo treatments, then make sure its an iron alloy. Otherwise it may be a waste of money and you may not ever know a difference either way. For cranks however, it's not a bad idea for racers. I am skeptical for the street racer though. Shot peening is a proven way to improve durability so check it out, otherwise you could end up chasing a fad.
warmonger
