Very interested in hearing recommendations for a crank in a stock block 400 B1 build.800hp range.Is it better to use the 400 or 440 mains?
Always appreciate your feedback.

I have a B1 512 and I use a Molnar 4.25 stroke crankshaft. I would run the 400 mains for 2 reasons. 1. strength of the block and 2. bearing speed, no need to have a higher bearing speed then necessary.



Joe

Thanks Joe,
I read different opinions, the larger 440 main size may provide larger overlap? Increasing the strength of the actual crank? Did you run aftermarket mains, I've read different opinions on whether a girdle like the BCR type are actually necessary or just use good aftermarket main caps only? I have a 230 block and a BCR kit, time to decide on the actual crank specs and if I will pay for the girdle installation.

I think the rod journal overlap is not a valid concern with any decent forged steel crankshaft, especially with many racers using 4 3/4 inch storke on many high end all out race Mopar engine builds these days I have built a bunch of 400 block strokers motors from mild to wild, with no girdles yet I do swapped the main caps out for the old(Milidon sells the now) Mopar brand Ductile iron and ARP main studs. I do use the Federal Mogul narrow full groove main bearins, part # 4094M My old pump gas 518 400 stroker made 775 HP on Oregon pump swill with the ductile iron main caps and 4094M main bearings, I raced the heck out of it shifting it at or above 7000 RPM for many passes, drove it on the street for a couple of hundred miles also If you want to make a motor that will live at 900 + HP buy a race block

Either main size will work well with a 4.25" Stroke. Personally I'd rather have the strength in the caps and main webs and use the smaller but still graciously adequate 400 main journals...but opinions vary.

With a 2.200" rod journal and a .990 pin (not to mention the minor reduction of the counterweight diameter itself to clear the webs) you're reducing a lot of crank mass compared to the heavy (and less precisely balanced) OEM set-up.