Small Block & Big Block Chevy Specific - stock 400 limit
04-24-2011, 10:55 PM
what is the rpm limit of a stock 400 crank ? my motor will be close to 14-1 compression ..solid roller cam..brodix heads..in my mustang with 4.56 gears and either 28-29 inch tire
04-25-2011, 06:30 AM
5500 safely. I have heard of some people going 6000K but i dont think its wise. Get a scat steel for 200 and make sure you balance it good
04-29-2011, 07:00 AM
Yea stock 400 cranks don't like much over 5500 even with a balance job.... with all the affordable aftermarket stuff out there and with the quality of the rest of the parts I wouldn't skimp on the crank
05-11-2011, 07:34 PM
^^^ Agreed wouldnt push much more than 5500
08-21-2011, 08:14 PM
I eneded up going with a eagle crank, its internal balance.. Nice stuff.. I built a 406
08-22-2011, 06:08 AM
I had Andy Jensen build me an el-cheapo 406 when I was in high school. I routinly shited at 6500RPM. Andy was appalled. He thought I should gear it up and shift at +7000RPM with the solid cam I had in there. This was with stock crank, rods and old TRW pistons. I think I would trust the stock, nodular crank to 6500 without thinking twice about it (assuming the machining work is good and it is balanced).
08-22-2011, 08:26 PM
The stock crank can handle about 6800 rpm regularly if it has been prepped correctly when it is re-ground, but you also need to change the clearances on the main jouranals at the same time. The stock crank will flex much more than a steel crank. I have taked a 3.5" SBC 400 main Scat Cast Steel lightweight crank well past it's recommended rpm limits in a budget dirt circle track car that was seeing 8,000-8,200 rpm regularly on a tacky clay track (it would pull your shoes off at the end of the night if you walked accross the surface). It is not a good idea to try this without having a very good balance job from an experanced shop, my friend that did the work has built IRL Indy car race engines, NHRA Top Fuel Alcohol Dragster, NHRA Funny Car, Trans Am race series engine's for Chyrsler's R&D team, and many more that I don't know about.
08-26-2011, 01:36 PM
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