BadAssEddie wrote:I thought the 351C, 351M, and 400 were all Ford 335 engines?
So Grubb, with that dyno sheet, is it more likely that is a 351M stroked or a 400 with a .030" bore? It looks to make a good power and a whole lot of torque with what you say are stock heads (I can't tell by inspection). How does one typically build that?
Since the 351M has a lower deck height than the 400 but with the same 4" bore (I assume it is the same since it is referred to a de-stroked 400), how to you stroke back out to 408? It seems like a 400 crank in a 351M block wouldn't do that.
Indeed, the 351C and 351M/400 are all 335 series, but as I noted above there are some differences. A 351M and a 400 are basically identical engines except for the pistons and crank. You can swap a 400 crank into a 351M along with the pistons and make it a 400 or vice versa. The 351C has the shorter deck height, ~9.2" vs ~10.3" on the 351M/400. I honestly don't know what is involved in stroking a 351C as I've never messed with them, but I assume it's similar to a Windsor, ie stroker crank, different pistons and/or rods.
As for building a 351M/400, there are a small handful of mfg's that make some aftermarket parts like higher compression pistons, and there are some performance parts from a 351C that will swap over (including most aftermarket heads and cams I believe). That said, the basic formula is a 400 with Badger or Tim Meyer flat top pistons which are good for about 9 to 9.5:1 CR, a good cam, and clean up the heads. Even the stock 351M/400 2V heads flow pretty dang good, they have canted valves and huge ports (bigger than those on some big-block heads). The downfall is the huge 77cc+ combustion chambers which were of a poor design and lead to lots of detention problems. This is why Aussie heads are of interest to 351M/400 builders as the have the good flow characteristics but with a smaller closed combustion chamber.
Back in the mid to late 70's Ford had real problems with detonation on these motors due to all the emissions crap and poor quality unleaded gas, so they retarded the timing and backed the compression all the way down to 7.74:1....and had a 400ci motor only making 158hp. That was a terrible time for all engines, even the 460 was making less than 200hp. I was strongly considering building a 400 instead of the 351W for my truck, but the huge weight savings of the Windsor and aftermarket support is what lead me the SBF route.
An interesting side note, you can use a crank from a 400 to stroke a Windsor out to 408", IIRC you use a 400 crank (with the snout machined off), Chrysler 360 rods and 302 pistons. That's the oldshool way to make a big cube Windsor before the days of stroker kits.
As for the dyno sheets, IDK. are those actual dyno sheets (engine or chassis?) or from a simulation like Desktop Dyno or Camquest? I used to post DD numbers but realized those are just a very vague representation of what a motor is making. Actually any dyno numbers/graphs can be fudged a bit. Honestly numbers don't matter, seat of the pant is where it's at. If it runs hard and suits your application then that's all that matters. If you really want to wring a motor out and see what it'll do take it to test and tune at the drag strip and start making passes. I don't know what kind of power the 351W be built makes, just an old junkyard motor somewhere between 200-400hp.
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