Ive always liked the thought of a big block build, but then i heard an ls7 can be stroked to 455 and now thats my aim. this wont be for a long time since im still a broke college kid, but when it happens i plan on making it scary.
big block vs small block
- Thread starter fatso86
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Who me? I never said that. I know that big inch small blocks make power and torque down low, but they *don't* rev high, and are more susceptible to breaking at higher RPMs, as opposed to a big block, which tend to be more reliable. Actually see what kornball426 said here...SScamino said:
Thank you, well said.kornball426 said:
And then there's the LS7. What, 7-8k rpms? 427ci, small block. And i've seen plenty of small blocks rev high, hell i've seen them SCREAM! But i almost never see a big block do that. And i usually see more power out of small blocks. At least on street cars. Dedicated, tube frame etc, drag cars are a different story.
454muscle said:
Sorry I just got confused by this. I just assumed since you said revving high that you meant to make power out of a big inch small block.... I shouldn't have assumed. My fault haha. But if you got all the good stuff than I don't see why revving would be a problem. But then again I haven't read much into the GEN I big cube small blocks..
The reason you see more power out of small blocks is you can get a bangin set of heads and a nice rotating assembly for like 2 grand. The heads alone on a BBC are going to set you back 2 grand for a set of nice Darts or Brodix or something similar, and you can spend a lot more than that. Not many people have the scratch to drop to build a worked big block for a toy or a daily driver. And pistons, rods, lifters, cams, intakes, headers, everything is more expensive for big blocks. If you have the money to spend and you want to spend it big blocks will stomp small blocks... But your bang for the buck is still a small block.
And who cares if big blocks don't scream? 5,500 is stock valve train 454 territory and with upgraded rod bolts and better valve train, and even better a forged rotating assembly there's no reason why a big block can't do 6,500 or even 7,000 or more and survive. There's a rule of thumb that you should never exceed a piston speed of 5,000 feet per minute or your engine won't have much of a serice life... With that in mind a 454 can do 7500rpm without exceeding that limit and a 455 can do a little over 7,000 as long as your rotating assembly can hold together. Of course there's no reason to do that unless you've got a race car and are more worried about winning than next time your engine will need a rebuild.
But RPM's aren't that important anyway, you can easily make up for what you don't have in revs with torque and gearing. The whole RPM thing is propaganda from the import scene... Who cares if your honda does 9,000 rpms it only has 120 horsepower and 80ft/lbs of torque my diesel pickup can beat it and it only revs to 4,500 rpm but it makes 450ft/lbs at 1,500 rpms and a measely 225hp at 3,000 but it's enough to beat a civic with ease.
And who cares if big blocks don't scream? 5,500 is stock valve train 454 territory and with upgraded rod bolts and better valve train, and even better a forged rotating assembly there's no reason why a big block can't do 6,500 or even 7,000 or more and survive. There's a rule of thumb that you should never exceed a piston speed of 5,000 feet per minute or your engine won't have much of a serice life... With that in mind a 454 can do 7500rpm without exceeding that limit and a 455 can do a little over 7,000 as long as your rotating assembly can hold together. Of course there's no reason to do that unless you've got a race car and are more worried about winning than next time your engine will need a rebuild.
But RPM's aren't that important anyway, you can easily make up for what you don't have in revs with torque and gearing. The whole RPM thing is propaganda from the import scene... Who cares if your honda does 9,000 rpms it only has 120 horsepower and 80ft/lbs of torque my diesel pickup can beat it and it only revs to 4,500 rpm but it makes 450ft/lbs at 1,500 rpms and a measely 225hp at 3,000 but it's enough to beat a civic with ease.
dan2286 said:
yes and no. The reason there is less power stock is the factory tune has a lot more to give in timing and fuel at open loop WOT, or as GM calls it PE (power enrichment) mode. Has nothing to do with emissions, but more as a safety measure for engine durability and reliablity. Which doesn't make sense because thats why the knock sensor is there.
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