427 crank in a 409

Does anyone know what the advantage is ?
I 've done a search and come up with nothing other than aparently thats what GM was doing in the early 60s with the Z-11
Thanks
Jeff

 

I didnt know that a standard big block crank will work in a W block.

 

Yeah, you can put a 427 crank in a 348 - 409.

For more info, go to: www.348-409.com

 

Is it this crank or the 454 crank that gives almost 500 cubes in a 409 block? I know they used them in boat engines and with an overbore got 500+ cubes!

Cheers, Glen.

 

Longer stroke means more torque. I've heard of even using a 454 crank.

 

The Drag racers started using the 454 crank in the 409's as it is a stronger crank. I once saw a 409 crank come out the bottom of a racer--not a pretty sight--when he cought 3gear.

 

409 was over square, loved to rev, but not being a good ole smallblock; recipe for disaster. The Rat Motor cranks were probably built better, all the lessons learned, you know. Also offered an increase in stroke, but couldn't have been a drop in.

 

The 409 was half way between a small block and big block...length of a modern big block, but cam bearings were size of SBC, front timing seal size of SBC...409 mains are 2.5 and rods are 2.198, (sbc mains were 2.29 thru early 327, 2.44 after 327).

348 bore/stroke: 4.125 x 3.25
409 bore/stroke: 4.312 x 3.50
427 W : 4.312 x 3.650
427 (later): 4.251 x 3.76
454 : 4.251 x 4.00

Later 427 and 454 crank mains are 2.74 (from Motors Manual..."American V8 Engine Data Book by Peter Sessler, MotorBooks Int'l. lists wrong numbers. That book has a LOT of simple errors in it. My specs for the 427W came from the Data book, so they may be wrong, but I don't think so).

To drop a 454 crank into a 409, you either have to turn the crank mains down .250 (a full quarter inch! Do that on any other application, and you'd certainly consider the crank junk), or open up the main bearing caps. That makes them thin, so you should use high quality aftermarket 4-bolt mains. But not splayed bolt, as the block won't support that.

So, with a 454 crank, you still have a bore larger than a 454, with a 1/2-inch stroke on it. Comes out to 480-cubes and change.

I'm putting one together with Lamar Walden for my gasser...solid roller cam, aluminum heads, tunnel ram...bad sumbitch.

-Brad