Crank questions...

Basic tech questions such as future setups, different turbo kits, car diagnosis, etc
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Radicalrobs240sx
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Crank questions...

Post by Radicalrobs240sx »

Hey guys I'm somewhat new to the 240 scene, I've owned my 91 240 since the winter and I've been planning a KA-T build since the first day I got the car running. I'm concerned about the crankshaft... all you guys pushing 400 plus horsepower what are you running for cranks? It's not an easy task to find a crank for this engine however they are out there, I'm just wondering at what point would I have to seriously consider upgrading my crank to FCW forged horsepower wise. My goal right now is to come close to the 400 horsepower mark, but would it make sense to upgrade my crankshaft or is it safe to Run the stock crank at that power? Some more info would be greatly appreciated and it would be great to hear what you guys are running for cranks in your Kat builds, would help me out a ton.
jaysol92
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Re: Crank questions...

Post by jaysol92 »

The stock crank is very strong, it's all about rpm not power. High rpms on our motors can snap the nose off of it. Plenty of guys have made much more than 400 on the stock crank. Just get it balanced and polished if you wanna do an easy modification to it. Running an ati super damper will help you a lot with harmonics as well.
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flip240
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Re: Crank questions...

Post by flip240 »

^ exactly as said above. KA24 stock cranks are very reliable and can hold quite a bit of power. Nissan has been built them to be just as tough as the L-series engines used in the 70's and 80's. Those engines were used extensively in racing; though the main difference is that KA cranks used a HCW design but were tested to still be suitable for racing purposes. There are dozens or more of KA24 owners running upwards of 400+whp on stock KA cranks. If you're worried about it, have a reputable shop examine the crank for defects and you'll be good to go. I also recommend going with the ATI super damper. It is slightly heavier than the OEM pulley but will ensure that your engine will run smoother in the rev range (The rubber in your factory pulley is already deteriorated anyway!)
- Phil - Concord Gray S14 - 339 rwhp, 340 ft-tq @ 12psi
Daily driven turbocharged KA24 for 10 years and counting. 2004-2014
My setup: KA24DE-T
tuzzio
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Re: Crank questions...

Post by tuzzio »

The important part is getting it balanced as it is only semi balanced from the factory. But thats assuming you'd like to rev it higher than the stock limiter. Aside from that, you'll be just fine. At 400whp the crank isn't going to be anywhere near the weak point.
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