crankshaft question?

[kyleozzie]

just got back from the machine shop, he seems to think i need to upgrade my crankshaft to at least a cast steel. has anyone heard of stock LT crank failing on a street strip motor 450 WRHP? thanks guys

[sman]

I wouldnt think so, but im not much of a ltx guy.

[JoeliusZ28]

absolutely not. The stock crank is one of your strongest options until you start looking at expensive forged cranks.

[sman]

Exactly what I was thinking, cranks are usually good for quite a bit of power from the factory, no matter what car.

[kyleozzie]

sweet, i thought so.. but just making sure well this will save me some money! lol looks like ill be buying more stuff tonight

[Fbomb]

Isn't the one that came factory cast steel? Powdered metal?

[JoeliusZ28]

i couldnt tell you what it is but any engine builder will tell you that a stock crank is pretty much the best of its type. They have BY FAR the least defects, and can hold well over 450rwhp. IMO the only time you need to worry about runing a stock crank is either if you are making a LOT of power, or you are rev-limiter launching with traction... thatll split one in half eventually.

[WMCCjames]

Your crank is already cast steel, so replacing it with an aftermarket (read, less quality) cast steel crank would just be dumb. Anybody that doesn't know their materials has no buisness machining them.

The rule of thumb on factory cast cranks in a SBC (at least GenI's) was that you were safe until around 450-500ft/lbs. After that it's a crap shoot.

[DETROITMUSCLE]

sounds like you need to find a new machine shop

[ThreeHonks]

sounds like you need to find a new machine shop

thats what I told him last ngiht over the phone. I hope I answered all of your questions.

The crank in an LTx is actually cast iron. I have seen well over 600whp put through them. They hold up to nitrous and boosted applications as well. I have a spare in the garage waiting just in case. The stock crank should be the least of your worries, and I mean the very LEAST

[kyleozzie]

Well I told him that I want this thing to be as bullet proof as I can make it, which is why I am converting to the splayed setup. And I think with that he just thought it would make sense to put a better crank in. He said it would be fine but he doesn't recomend reving it over 7 lol but I told him it probaby won't see over 6500 much. So he was fine after that. Lol but thanks guys for all the info!! I am glad to have you guys!

[kyleozzie]

thats what I told him last ngiht over the phone. I hope I answered all of your questions.

The crank in an LTx is actually cast iron. I have seen well over 600whp put through them. They hold up to nitrous and boosted applications as well. I have a spare in the garage waiting just in case. The stock crank should be the least of your worries, and I mean the very LEAST

Yeah you helped me a ton!!! Thanks ryan

[ThreeHonks]

Just an FYI for all you other guys out there. I have 3500 miles on my motor with about 50 track passes. It sees about 7000 rpm shift points, and has seen it PLENTY of times on the street. I will be pulling a main cap and rod cap to check the bearing and it see if the caps are walking at all. I will start a thread and give you an update of how it looks. I will also post results of my UOA. (I have been using Mobile 1 0w40)

[DETROITMUSCLE]

depending on your cam the motor may want to spin to 7K

[ThreeHonks]

depending on your cam the motor may want to spin to 7K

I still wouldnt hesitate to use the stock crank at 7500+ RPM The way I look at this is; if its built prefectly to spec, and the clearances are perfect, it will REALLY increse the amount of power components can handle (plus the stock crank is plenty strong)