Just build what you have and have fun. It's really not that difficult to figure out.
440 Crank in a 383
- Thread starter eschroeder1
- Start date
65 Cuda 340
Well-Known Member
A 383 has the same bore size as a 426 Hemi. Just saying. . . .
The little things again.
What a 383 does NOT share in common with the HEMI.... does it really even bear mentioning?
Go watch Nick's garage. He has notoriously conservative Dyno. He built a numbers matching hemi, right down to the points ignition. That bad boy made damn close to 500 HP, bone stock, manifolds and all!
The factory 383 would struggle to get to 400. It's just not the same league.
Correlating different engines based on bore sizes (and other such metrics like rod ratio, bore and stroke ratio etc) is misinforming people. That's the little **** that barely matters.
65 Cuda 340
Well-Known Member
My comment was a response to prior comments disparaging the 383's supposedly small bore. Of course a stock 383 makes no where near the power of a stock 426 Hemi. C,mon. . . .
Ok, thanks for clarifying. It wasn't clear
65 Cuda 340
Well-Known Member
Oh, that's OK. Hope I wasn't too much of a smartass. 
I was being smart too. We're a callous bunch aren't we? This place isn't for the thin skinned.Oh, that's OK. Hope I wasn't too much of a smartass.
mhuppertz
Well-Known Member
The great thing about the 383 is you can wrap the pee out of it and it will never break. It's a magic motor.
What makes it magic?
a70duster
Member
Volume of a cylinder times the number of cylinder (for the newbies)
((Bore² x π / 4) x Stroke) x 8
(4.250² x 3.1416 / 4 ) x 3.750 x 8 = 425.59 and that rounds up to 426 inches cubed.
65 Cuda 340
Well-Known Member
Formula for volume of any cylinder is pi times r squared times h, where r is the radius and h is the height. Radius is half the diameter, and pi rounded off is 3.142 (or however many numbers you want to go out to, as pi is a never ending decimal).
For an automobile engine, the bore would be the diameter, and height would be the stroke, and, of course, you need to multiply the volume of one cylinder by however many cylinders the engine has.
You can start by dividing the bore by 2 and then squaring it, or you can square the bore and divide by 4. Same number either way. You can avoid remembering pi by using one of the formulas available online that mathematically combines various of these numbers. There's more than one such formula, because there's more than one way to combine the numbers. Downside is that you have to remember the formula. For me, it's easiest to remember (pi)(r squared)(h) times however many cylinders the engine has. But whatever floats your boat.
Any way you figure it, put a 440 crank in a standard bore 383 and you end up with 426 cubes.
For an automobile engine, the bore would be the diameter, and height would be the stroke, and, of course, you need to multiply the volume of one cylinder by however many cylinders the engine has.
You can start by dividing the bore by 2 and then squaring it, or you can square the bore and divide by 4. Same number either way. You can avoid remembering pi by using one of the formulas available online that mathematically combines various of these numbers. There's more than one such formula, because there's more than one way to combine the numbers. Downside is that you have to remember the formula. For me, it's easiest to remember (pi)(r squared)(h) times however many cylinders the engine has. But whatever floats your boat.
Any way you figure it, put a 440 crank in a standard bore 383 and you end up with 426 cubes.
33IMP
Well-Known Member
Your pi÷4 is where the .7854 constant that I use comes from. A handy little circle on most calculators.
B x b x s x 8 x .7854
B x b x s x 8 x .7854
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