Pagey 10 Posted February 9, 2019 Hi new guy here , am building a 408 stroked clevo and tossing up between a cast or 4340 crank. I have chi 208 3v heads and single plane manifold, will put a hyd roller 240@.50 .612 lift and a 850 DP . Will go into a xy sedan with a toploader. Will only be a weekend streeter . Is 4340 warrented or would the cast be safice Share this post Link to post Share on other sites
gerg 10,871 Posted February 9, 2019 Hi new guy here , am building a 408 stroked clevo and tossing up between a cast or 4340 crank. I have chi 208 3v heads and single plane manifold, will put a hyd roller 240@.50 .612 lift and a 850 DP . Will go into a xy sedan with a toploader. Will only be a weekend streeter . Is 4340 warrented or would the cast be saficeCast cranks are much tougher than people will give them credit for. A stock Clevo 4MA will spin to 7500 no probs if everything's balanced and prepped right. If you can get hold of a neutral balance one, even better. If it's just a weekend cruiser, that might not even be an issue.Being a stroker, it will be all about the mid-range torque, not the top end, so even less reason to go steel. Steel cranks are really only for serious, sustained rpm. Total overkill for what you're building. Sent from my CPH1607 using Tapatalk 1 bear351c reacted to this Share this post Link to post Share on other sites
Pagey 10 Posted February 9, 2019 Was thinking as much. So a scat 9000 with h beams and srp forged pistons will be fine? The $800 saving would be nice. Share this post Link to post Share on other sites
Pagey 10 Posted February 16, 2019 Anyone else with some info? Share this post Link to post Share on other sites
FORD_MAN 1,026 Posted February 16, 2019 With 408 & 240 @.050'' cam, peak HP would be around the 6000-6200ish rpm mark so fine for cast crank, I would upgrade to 4340 if regularly reving over 6800rpm, Tho wounding if CHI dual plane, airgap type manifold would be more suited for RPM range of engine, would make more low & mid range torque with dual plane over single plane. I could feel the difference when I changed from hi rise single plane to dual plane, picked up heap more low to mid torque (but was a 302lol) 1 gerg reacted to this Share this post Link to post Share on other sites
Pagey 10 Posted February 16, 2019 Your right about their dual plane , maybe down the track. Have modeled this build off the nulon xy engine, it uses a single plane. That's why I went that way. Have read the cast cranks take a bit to balance, have you had any experience with them? Cheers Share this post Link to post Share on other sites
bear351c 10,270 Posted February 17, 2019 Balanced is balanced, no matter what material it's made of..... Some companies grind material off the webs, some drill holes, (and/or fill with weights.) Just make sure you balance the WHOLE rotating assembly together. Flywheel/flexplate + crank + rods +pistons + harmonic balancer etc, etc. Share this post Link to post Share on other sites
Pagey 10 Posted February 18, 2019 Yes , I will get the complete assembly balanced. Just heard the cast takes more to balance, so it doesn't end up much cheaper. Would you go 4340 or cast ? Share this post Link to post Share on other sites
bear351c 10,270 Posted February 18, 2019 All depends on the rev range you want. As others have said, 5,500 -6,000 rpm is fine on a balanced stock crank. Clevo's weak points are the oiling system, the 5/16 rocker studs, and standard valves will pop their heads off at 6 grand. Strokers are torque makers, and the lower the rev range the longer everything will last. 1 gerg reacted to this Share this post Link to post Share on other sites
Pagey 10 Posted February 18, 2019 Was thinking about 6400 at most . My heads have the c3 assembly from chi. Cheers for the info aswell mate. 1 bear351c reacted to this Share this post Link to post Share on other sites
bear351c 10,270 Posted February 19, 2019 Mmmm..........very nice bit of kit. ^ ^ ^ ^ Share this post Link to post Share on other sites