I have a 427 crank that is offset ground for 2.10 rods. Still need to have the mains and counter weights turned down to fit the 409.
Thinking about a stroker short block, going rate for a block?
- Thread starter Austin Bubbletop
- Start date
Small block rod would give more clearance/less grinding for clearance between rod and block.
Reading these threads brings back a lot of fond memories for me. I had a '61 348 engine that I had bored and stroked to 434 cubes. Used a 454 crank, Edelbrock heads, 396 rods, special pistons made by Egge, 750 cfm Edelbrock carb and aluminum manifold. I don't recall the cam, but what a great engine. I put it in my '56 Chevy straight axel gasser wagon with TH400 trans. and 3.73 gears. I really miss that engine and car. Sold several years ago but the marks from hole shots in my driveway, are still there. Had a lot of power. Enough for me. Just something about those "W" engines, Carmine.
You use 2.10 x6.135 or longer rod. It slows down the bearing speed. Same as the 409 block had over the 396-454 block.
At 7000 rpm, the reduction in mean bearing speed for the rod bearing going from 2.2” to 2.1” is less than 5 percent. Doesn’t seem worth anything. I guess the rod would be lighter which certainly doesn’t hurt but with the heavy 409 piston I would prefer the extra strength of the larger pin and rod.
That is more or less what I was thinking. As much as I like "lighter" stuff, the pin size issue and overall strength with relatively heavy 409 style pistons would probably convince me not to do it.
The crank I have is offset ground so it has more stroke.
Those pro stock guys are using Honda size rod journals. Now they do have a lighter piston.
Dave at Mile High cranks says you can get as much as 3.84 stroke with the 2.10 offset grind.
3.84 on a 427 crank. Take .100 off the journal, the pin center moves out .050 by offset grinding making .100 more stroke.
True. Now consider this a 4.600 bore 14:1 for a 4.25 stroke and 6.385 rod is still lighter than my 4.370 bore 13.5:1 4" stroke and 6.385 rod pistons with pocket milling and under crown profiling. And pro stock guys only care about making it through the weekend instead of 300 runs.
Did some work on a couple of Hemis. One with stage 5 heads and one with Millenium heads which does use a flatter dome. Both over 14:1. They were still lighter!
Pro: Faster acceleration and less stress on everything
Con: Too light and they flex causing all kinds of nasty problems from galling pin bores to beating the locks out and binding of the piston on the pin. Better to be a little heavier in this case. Now if someone would make a box style piston for the 409 that would be awesome. Lighter piston, lighter pin, and a shorter stiffer pin.
