RPM's and Torque Delivery: Big Block vs Small Block
#2511045
06/20/18 09:05 PM
06/20/18 09:05 PM
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Spartan040
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We all know that the big blocks have a lot more power potential than the small blocks, but I've seen some small block stroker motors in the 408-426 CI range that really scream, edging around 500 HP and torque numbers around the same figure (I've even seen a few go as high as 600). Given that they're lighter and far less expensive than big blocks, I've had to at least reconsider the idea of using a small block stroker versus sticking with my plans to build a lightweight aluminum 440 stroker in my planned Challenger build. So, my question isn't about power levels so much as how do the two engine types deliver power to the ground differently, and how do they rev differently? As I understand it (although I could be wrong, I'm still learning), the big blocks have a lot more low-end torque and you get a much larger kick in the pants than you would with a small block, whereas the small blocks have a more even torque delivery throughout the powerband which makes it easier to launch them without going sideways and boiling tires, and to have more consistent torque delivery throughout the RPM range, similar to the Gen 3 Hemis. Am I correct here? Or way off? I'm also fairly sure that the small blocks rev higher and faster than the big blocks, topping out somewhere in the low 7k range versus the big blocks that top out around the mid to high 6k range. While revving faster could be an advantage, is it really a benefit to rev higher if your peak HP and torque numbers were a good ways below that? I realize the SB vs BB debate has been going for a long while, but I just thought it might be fun to throw a little gasoline on the embers
Last edited by Spartan040; 06/20/18 09:10 PM.
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Re: RPM's and Torque Delivery: Big Block vs Small Block
[Re: Spartan040]
#2511062
06/20/18 09:48 PM
06/20/18 09:48 PM
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HemiRick
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With the light pistons in most stroker combos, they all rev faster than stock....In the old days the 451 BB stroker was called the BB that revved like a small block....With 5 bolts per cylinder and opposed to 4 the BB is always easier to keep head gaskets in.
Yes low end torque is largely a function of cubic inches...so BB's also win here too.
Last edited by HemiRick; 06/20/18 09:50 PM.
Take care, Rick 68 Coronet R/T 440 & 68 Charger 528 Hemi,and 5 Challengers! 6 cyl, 318, 360, 383, 451
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Re: RPM's and Torque Delivery: Big Block vs Small Block
[Re: Spartan040]
#2511120
06/20/18 11:25 PM
06/20/18 11:25 PM
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Skeptic
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And the big block stroker kit I was looking at from 440 Source makes use of forged aluminum pistons and rods, so I'm sure that would help it rev better, but I'm not too sure about the long-term longevity of the aluminum parts.
440 Source doesn't list any aluminum rods on their website.
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Re: RPM's and Torque Delivery: Big Block vs Small Block
[Re: Skeptic]
#2511122
06/20/18 11:27 PM
06/20/18 11:27 PM
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Spartan040
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And the big block stroker kit I was looking at from 440 Source makes use of forged aluminum pistons and rods, so I'm sure that would help it rev better, but I'm not too sure about the long-term longevity of the aluminum parts.
440 Source doesn't list any aluminum rods on their website. My bad, could have sworn I'd seen those
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Re: RPM's and Torque Delivery: Big Block vs Small Block
[Re: WO23Coronet]
#2511186
06/21/18 02:09 AM
06/21/18 02:09 AM
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pittsburghracer
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It’s kinda fun beating up on big blocks with our little blocks. I love them both but boy are the small blocks easier to work on in tight spots
1970 Duster Edelbrock headed 408 5.984@112.52 422 Indy headed small block 5.982@112.56 mph 9.42@138.27
Livin and lovin life one day at a time
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Re: RPM's and Torque Delivery: Big Block vs Small Block
[Re: Spartan040]
#2511189
06/21/18 02:12 AM
06/21/18 02:12 AM
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Spartan040
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Just out of curiosity, I know there aren't any aluminum small blocks but how much would aluminum heads, water pump and housing, and manifold reduce the weight of a SB?
I'm still leaning more towards a BB because I know I can lighten that thing to around 475 pounds with enough aluminum, and as someone else said there's no replacement for displacement. I just thought I'd entertain the idea of a SB as well. Then again though, it would be easier to find space for the power accessories, Classic Auto Air system, and XV engine bay brace if I went with the small block, nevermind it being easier to work on in the engine bay....ah, decisions, decisions.
All that being said, I don't want to get too crazy with the power on either of them, there's no traction or stability control in these cars like there is in the modern Challenger.
Last edited by Spartan040; 06/21/18 02:20 AM.
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Re: RPM's and Torque Delivery: Big Block vs Small Block
[Re: FastmOp]
#2511229
06/21/18 09:58 AM
06/21/18 09:58 AM
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Spartan040
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You can get traction control. Just go FAST EFI Really? They have that? How's it work?
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Re: RPM's and Torque Delivery: Big Block vs Small Block
[Re: Spartan040]
#2511341
06/21/18 03:00 PM
06/21/18 03:00 PM
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HotRodDave
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My biggest beefs with teh BB are the pain in the but to work on simple things like spark plugs, tighter header clearance, plus the extra weight and then add on the fact these stroker SBs make so much TQ now it is hard to hook them on the street much more that an 818lb TQ is fun it can be dangerous and hard to control on the street like most of the stuff I get to build now being so far from a track. A stock 5.9 magnum block is a cheap easy roller cam, can handle as much HP as a 440 block, better valve placement on a common head, better weight distribution, much better plug placement for burn and working on, the SB is a bolt in factory installed in many more aplications... I just see limited use for the BB in street cars like original BB cars or all out race cars where your running big indy heads big strokes and big money in the car to make it hook. I cant get the 410 SB in my dakota R/T to hook on the street for anything and am always trying to kill some TQ, I have even considered selling the motor and going back to a 360.
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: RPM's and Torque Delivery: Big Block vs Small Block
[Re: Spartan040]
#2511348
06/21/18 03:15 PM
06/21/18 03:15 PM
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Joined: Jan 2005
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TRENDZ
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Who told you there are no aluminum small blocks? You can order one today and have it in a week if you have the money. You got $7500 laying around?
"use it 'till it breaks, replace as needed"
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Re: RPM's and Torque Delivery: Big Block vs Small Block
[Re: TRENDZ]
#2511455
06/21/18 07:15 PM
06/21/18 07:15 PM
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Spartan040
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Who told you there are no aluminum small blocks? You can order one today and have it in a week if you have the money. You got $7500 laying around? I just assumed there weren't because I couldn't find any online. $7500? The big aluminum blocks are surprisingly $2000 cheaper
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Re: RPM's and Torque Delivery: Big Block vs Small Block
[Re: HotRodDave]
#2511456
06/21/18 07:18 PM
06/21/18 07:18 PM
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Spartan040
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My biggest beefs with teh BB are the pain in the but to work on simple things like spark plugs, tighter header clearance, plus the extra weight and then add on the fact these stroker SBs make so much TQ now it is hard to hook them on the street much more that an 818lb TQ is fun it can be dangerous and hard to control on the street like most of the stuff I get to build now being so far from a track. A stock 5.9 magnum block is a cheap easy roller cam, can handle as much HP as a 440 block, better valve placement on a common head, better weight distribution, much better plug placement for burn and working on, the SB is a bolt in factory installed in many more aplications... I just see limited use for the BB in street cars like original BB cars or all out race cars where your running big indy heads big strokes and big money in the car to make it hook. I cant get the 410 SB in my dakota R/T to hook on the street for anything and am always trying to kill some TQ, I have even considered selling the motor and going back to a 360. Weight isn't a huge concern to me since I'm banking on using an aluminum block, but I didn't know about the other stuff. And I'm only planning to make around 500-600 torque in a 500 inch stroker, which is a fairly mild build for an engine of this size. Part of me just has an emotional connection to and desire for a super cool aluminum big block, but if it's truly too much of a disadvantage I'll reconsider
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Re: RPM's and Torque Delivery: Big Block vs Small Block
[Re: Spartan040]
#2511497
06/21/18 09:53 PM
06/21/18 09:53 PM
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Posts: 2,540 Milwaukee WI
TRENDZ
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Google “mopar performance A8” this will get you to the “available now” aluminum small block that mp sells for sprint cars. Many special parts are needed. Or contact Ernie Elliot race engines for thier own aluminum casting to be used with P7 heads. If you have money you can get a new aluminum small block.
"use it 'till it breaks, replace as needed"
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Re: RPM's and Torque Delivery: Big Block vs Small Block
[Re: TRENDZ]
#2511515
06/21/18 10:32 PM
06/21/18 10:32 PM
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Joined: Jul 2015
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Spartan040
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Google “mopar performance A8” this will get you to the “available now” aluminum small block that mp sells for sprint cars. Many special parts are needed. Or contact Ernie Elliot race engines for thier own aluminum casting to be used with P7 heads. If you have money you can get a new aluminum small block. I think I'll consider an aluminum block for the 440 only, it's just too expensive and more difficult for the small block.
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