383 build
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Joined: Jun 2010
Posts: 105
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From: Indianapolis, Indiana
Car: 88' Z
Engine: 350 .60 over
Transmission: W/C T5
Axle/Gears: 3.23
383 build
one simple question do i have to bore the 350 .030" over. With the added stroke of the 400 crank and the standard bore of the 350 (4") it should make it a 383 ? someone told me you have to bore it .030" over but wouldnt that make it a 378 ?
Joined: Mar 2000
Posts: 43,187
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Check your math. What are you using for the value of pi? Using 3.14159 (which contains sufficient significant digits), 4.030" bore with 3.75" stroke in 8 cylinders produces 382.6668677325 cubic inches.
My Palm calculator has a preloaded value for pi of 3.1415926535898. Using that, it comes out to 382.66719095765 cubic inches.
Either way, rounding to 3 significant digits produces 383 cubic inches.
On a 4.000" bore with 3.75" stroke, 8 cylinders, it comes out to 3.76.991 cubic inches - rounds off to 377 cid.
(Formula: bore squared, divided by 4, times pi, times stroke, times number of cylinders)
My Palm calculator has a preloaded value for pi of 3.1415926535898. Using that, it comes out to 382.66719095765 cubic inches.
Either way, rounding to 3 significant digits produces 383 cubic inches.
On a 4.000" bore with 3.75" stroke, 8 cylinders, it comes out to 3.76.991 cubic inches - rounds off to 377 cid.
(Formula: bore squared, divided by 4, times pi, times stroke, times number of cylinders)
Joined: Mar 2000
Posts: 43,187
Likes: 42
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Right, the 6.2832 is pi times 2 (the "2" being 8 divided by 4). Oh, and that's rounded off.
But that's like giving a fish vs. teaching to fish.
Now, if we really want to teach to fish, the volume of a "cylinder" is the area of the base times the height. The base equates to the bore, and the height to stroke. And, we all remember that the area of a circle is pi times the radius squared (the radius being half the diameter, and D/2 squared is diameter squared divided by 4 - remember the "4" from the first line?).
Junior high math applied to the real world - and we all hated word problems on math tests.
But that's like giving a fish vs. teaching to fish.
Now, if we really want to teach to fish, the volume of a "cylinder" is the area of the base times the height. The base equates to the bore, and the height to stroke. And, we all remember that the area of a circle is pi times the radius squared (the radius being half the diameter, and D/2 squared is diameter squared divided by 4 - remember the "4" from the first line?).
Junior high math applied to the real world - and we all hated word problems on math tests.
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: 383 build
YOu dont have to over bore it if you use the GM 3.80" stroke and dont deck the block (Well its 382" technically...), but thats 1100 bucks and not worth it.
On Probation
Joined: Oct 2008
Posts: 6,319
Likes: 19
From: Northern Utah
Car: seeking '90.5-'92 'bird hardtop
Engine: several
Transmission: none
Axle/Gears: none
Re: 383 build
Right, the 6.2832 is pi times 2 (the "2" being 8 divided by 4). Oh, and that's rounded off.
But that's like giving a fish vs. teaching to fish.
Now, if we really want to teach to fish, the volume of a "cylinder" is the area of the base times the height. The base equates to the bore, and the height to stroke. And, we all remember that the area of a circle is pi times the radius squared (the radius being half the diameter, and D/2 squared is diameter squared divided by 4 - remember the "4" from the first line?).
Junior high math applied to the real world - and we all hated word problems on math tests.
But that's like giving a fish vs. teaching to fish.
Now, if we really want to teach to fish, the volume of a "cylinder" is the area of the base times the height. The base equates to the bore, and the height to stroke. And, we all remember that the area of a circle is pi times the radius squared (the radius being half the diameter, and D/2 squared is diameter squared divided by 4 - remember the "4" from the first line?).
Junior high math applied to the real world - and we all hated word problems on math tests.
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Member
Joined: Jun 2009
Posts: 344
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From: Southern California
Car: 1992 Camaro RS
Engine: 8.0:1 454/Mild Hyd roller/Accel DFI
Transmission: WC T5
Axle/Gears: Stock 1992 open 7.5" 2.73 ratio
Re: 383 build
heres the easy way
bore x bore x stroke x .7854 x (number of cylinders)= cu in of displacement
4.0x4.0x3.75x.7854x8=376.992
Blamo!
bore x bore x stroke x .7854 x (number of cylinders)= cu in of displacement
4.0x4.0x3.75x.7854x8=376.992
Blamo!
Supreme Member
Joined: Sep 2009
Posts: 1,319
Likes: 0
From: Tigard, OR
Car: 87 iroc-z camaro
Engine: 305TPI
Transmission: 700R4
Axle/Gears: G92 3.23 posi
Member
Joined: Jun 2009
Posts: 344
Likes: 0
From: Southern California
Car: 1992 Camaro RS
Engine: 8.0:1 454/Mild Hyd roller/Accel DFI
Transmission: WC T5
Axle/Gears: Stock 1992 open 7.5" 2.73 ratio
Re: 383 build
hahaha man this is the easy stuff! Wait until you are trying to figure compression height for piston to valve clearance. Better break out the notebook. Hit the link for ultra easy version
http://www.csgnetwork.com/cubicinchdispcalc.html
This website has some extremely useful java calculators.
http://www.csgnetwork.com/cubicinchdispcalc.html
This website has some extremely useful java calculators.
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