I'm planning on show cars forged piston and rods. Shooting for around 10 to 1 comp. But why would it be considered a torque motor? It has a slightly longer stroke than a 350 3.48 compared to 409s 3.50 and a larger bore than a 400. And a 350 crank in a 400 block makes for a rpm screaming 377. I would think a 409 would be ideal. With the limitation being the heads. Not trying to start an argument. Just trying to learn more about these 409s
Gus, that's really a good observation. 348s and
stock stroke 409s have this "torque motor" reputation which is a bit of a fallacy. They are short stroke/long rod motors which (everything else being equal) should like to rpm...except for the piston weight, so they are generally built to avoid excessive rpm, and make best use of available cylinder heads. In some ways they are in between SBCs and BBCs, in some ways they are different animals entirely.
So, when you look at the premier W engine builders today, cylinder heads, intakes and light pistons get the most attention, it seems. They also have accumulated a lot of data on cam profiles which work with these newer pieces. Many are revised BBC profiles.
Short story, Don is exactly right. Many folks tried these Thumpers and hated them because they fell short in several ways. Actually, a generic W motor would be much happier with a simple single-pattern cam than a radical dual-pattern like a Thumper, but there are many moderate dual-pattern profiles that work too.
These are just unqualified opinions and observations. I regularly twisted my stock-stroke, stock-rod 409 to 7300 rpm with no problem for 4 years. It does have pretty light pistons in it and stockish 583 heads. Still in one piece.