Can a 370 outperform a 383?
12-10-2008, 02:30 PM
#62
yeah, im trying to get a better understanding ..but can somebody simplify this stuf...lol.. for instance exactly what is bore and stroke..and then these crazy numbers like 3.905859595 and then 4.0986764..lol.. im trying to understand what all that is.
12-10-2008, 02:40 PM
#63
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Bore and stroke for the "traditional" LS1 383 is 3.905" X 4.00" = 383.249 cu. in.
Bore and stroke for the "traditional" 6.0 iron block 370 is 4.030" X 3.622" =369.605 cu. in.
Bore and stroke for the "traditional" 6.0 iron block 370 is 4.030" X 3.622" =369.605 cu. in.
12-10-2008, 03:12 PM
#67
My last 370 which was a complete load of junk parts picked up from around the shop with a set of crap cylinder heads made 481RWHP through a 9" with 4.57 gears and no dyno tricks. Piston to bore clearance was .0095", it ate a quart of oil every 4-500 miles... etc... etc...
Try and do that on a 383 LS1 with the same bull$hit combo of parts...
Shane
Try and do that on a 383 LS1 with the same bull$hit combo of parts...
Shane
Not saying the PRCs were bad or anything, just both setups were not optimized and the 4.00 bore made better power.
12-10-2008, 03:24 PM
#68
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3.905" is the diameter of the bore of one cylinder. 4.00" is the distance the piston travels in 1 "stroke" of the bore. By using a simple mathmatical formula for the volume of a cylinder the multiplying the result by 8 cylinders, you get the total displacement of the engine.
One common way to express this formula is:
displacement = pi x (bore/2)^2 x stroke x number of cylinders
Thanks,
Shane
12-10-2008, 03:26 PM
#69
There is the source of your misconception. Fully optimized, more cubes should make more power, no one will deny that. Optimized, however, includes bore x stroke. The LS1 block 383 by design is inherently flawed with a small bore and long stroke, and can never be fully optimized because of that. Without an optimized bore x stroke, you're simply trying to make up for a undersquare setup when you put a great top end on it that you would consider the the "best setup."
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12-10-2008, 03:36 PM
#70
180ls1: I do agree that you've misunderstood alot of what is being said in the thread. You're still in bigger is better mode. That's not always the case, and its been shown in this thread with math (not just opinions, actual formulas that dictate the subject).
Brad summed the thread up very well in his post, quoted below.
Brad summed the thread up very well in his post, quoted below.
and sorry to the op if i took this thread off topic.
12-10-2008, 03:51 PM
#71
yes that is correct but the thread strayed from that and that is what i commented on. I know that the head options for a 370 block give a big advantage i was just trying to clear up what bigbroncoss was saying where other people think he was saying something else.
not at all chief.
i dont think you understand what i am getting at. I know bigger is not always better like i said earlier. But when you have an engine that is slightly bigger and the components increase flow in perportion with the increase in size it will make more power then the smaller engine. That is not the case here but i wanted to make that clear. Hope that helps.
and sorry to the op if i took this thread off topic.
not at all chief.
i dont think you understand what i am getting at. I know bigger is not always better like i said earlier. But when you have an engine that is slightly bigger and the components increase flow in perportion with the increase in size it will make more power then the smaller engine. That is not the case here but i wanted to make that clear. Hope that helps.
and sorry to the op if i took this thread off topic.
12-10-2008, 05:47 PM
#74
There is the source of your misconception. Fully optimized, more cubes should make more power, no one will deny that. Optimized, however, includes bore x stroke. The LS1 block 383 by design is inherently flawed with a small bore and long stroke, and can never be fully optimized because of that. Without an optimized bore x stroke, you're simply trying to make up for a undersquare setup when you put a great top end on it that you would consider the the "best setup."
I was going to say this earlier, but I didn't want all the 383 owners to get their feelings hurt.
12-10-2008, 05:56 PM
#77
Your argument has nothing to do with the debate in this thread. I dont think you understand the bore argument. A 4.00 bore will always flow more than a 3.9" bore. At the end of the day the 383 in discussion could never flow as well as the 370 in discussion. This isn't something you can just vaguely say "well you have to have the right combination".... the combination (bore and stroke) is fixed in this debate. All you are doing is confusing youself.
12-10-2008, 06:17 PM
#80
Cubic inches only matter if there is the bore there to support it. IN THE CASE WE ARE TALKING ABOUT... the 370 has a bore that will support more power than the 383... and will make more power every time.
If your argument is "Cubic inches always make more power assuming the bore is the same" then i agree... who wouldn't... thats stating the obvious.