383?
10-12-2003, 11:46 AM
#1
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Join Date: May 2003
Location: KY
Posts: 5
383?
Please don't flame me--my car knowledge is growing at a steady pace, but I'm still, by far, a car newbie. Please bestow upon me the answers to the questions I have.
What makes a 383? Searching throughout the forum I hear people saying that they bought "kits" for their Z to make it a 383. Is 383 not the ci of the block? I mean, I really don't understand here.
What is involved with building one, as far as parts? What do you have to do with the rest of the vehicle if you do this?
Thanks in advance!
What makes a 383? Searching throughout the forum I hear people saying that they bought "kits" for their Z to make it a 383. Is 383 not the ci of the block? I mean, I really don't understand here.
What is involved with building one, as far as parts? What do you have to do with the rest of the vehicle if you do this?
Thanks in advance!
10-12-2003, 12:18 PM
#2
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Join Date: Oct 2002
Location: Upstate NY
Posts: 2,931
Sorry to be so basic; absolutely no flame intended.
383 cubic inches is the displacement or the "swept volume" the pistons displace during a trip from top to bottom of the cylinder bore.
A standard "350" has a 4.00 inch bore and a 3.480 inch stroke.
To calculate displacement: Bore (times) Bore (times) stroke (times) no. of cylinders (times) .7854
HINT: .7854 are the numbers in the upper left of a keypad. If you start in the corner and go clockwise you won't have to memorize the number. It's just PI over 4, BTW
For 350: 4.00 x 4.00 x 3.48 x 8 x .7854 = 349.85 cu. in.
If you just bore the block .030 inch, it becomes 4.03 x 4.03 x 3.48 x 8 x.7854 = 355.12 or a "355".
If you install a crankshaft with a 3.75 in. stroke vs. the stock 3.48 in. stroke, and bore the cylinders .030 in. oversize ("30 over"), you get: 4.03 x 4.03 x 3.75 x 8 x .7854 = 382.67 cu. in. or a "383".
Because you have increased the stroke, it is called a "stroker" .
A kit to build a 383 from a 350 usually includes:
*crank with 3.75 stroke
*new pistons, usually "30 over" complete with pins
*new rods of various lengths, often 5.70 (stock length), 5.85, or 6.00 inches long.
*appropriate piston rings and bearings.
The new assembly may be "externally balanced" which uses a flexplate or flywheel with eccentric weight, or "internally balanced", where any additional weight is added to the crank with "heavy metal". This uses a standard flywheel ("neutrally balanced"). A stroker kit may or may not come balanced. That should be figured into the cost of the conversion.
Depending on the hp levels you want, the kit cost can vary a lot.
IMO, for 500 or so flywheel (400+ rear wheel) hp, a Scat cast crank, hypereutectic cast pistons, and medium priced forged rods are adequate. Of course, if you don't spend 50% or more of your budget on heads or good porting, plus a good valvetrain, you won't get many of the benefits of the extra 9-1/2% displacement. BTW, You'll probably get many differing opinions on this paragraph.
My $.02
383 cubic inches is the displacement or the "swept volume" the pistons displace during a trip from top to bottom of the cylinder bore.
A standard "350" has a 4.00 inch bore and a 3.480 inch stroke.
To calculate displacement: Bore (times) Bore (times) stroke (times) no. of cylinders (times) .7854
HINT: .7854 are the numbers in the upper left of a keypad. If you start in the corner and go clockwise you won't have to memorize the number. It's just PI over 4, BTW
For 350: 4.00 x 4.00 x 3.48 x 8 x .7854 = 349.85 cu. in.
If you just bore the block .030 inch, it becomes 4.03 x 4.03 x 3.48 x 8 x.7854 = 355.12 or a "355".
If you install a crankshaft with a 3.75 in. stroke vs. the stock 3.48 in. stroke, and bore the cylinders .030 in. oversize ("30 over"), you get: 4.03 x 4.03 x 3.75 x 8 x .7854 = 382.67 cu. in. or a "383".
Because you have increased the stroke, it is called a "stroker" .
A kit to build a 383 from a 350 usually includes:
*crank with 3.75 stroke
*new pistons, usually "30 over" complete with pins
*new rods of various lengths, often 5.70 (stock length), 5.85, or 6.00 inches long.
*appropriate piston rings and bearings.
The new assembly may be "externally balanced" which uses a flexplate or flywheel with eccentric weight, or "internally balanced", where any additional weight is added to the crank with "heavy metal". This uses a standard flywheel ("neutrally balanced"). A stroker kit may or may not come balanced. That should be figured into the cost of the conversion.
Depending on the hp levels you want, the kit cost can vary a lot.
IMO, for 500 or so flywheel (400+ rear wheel) hp, a Scat cast crank, hypereutectic cast pistons, and medium priced forged rods are adequate. Of course, if you don't spend 50% or more of your budget on heads or good porting, plus a good valvetrain, you won't get many of the benefits of the extra 9-1/2% displacement. BTW, You'll probably get many differing opinions on this paragraph.
My $.02
Last edited by OldSStroker; 10-12-2003 at 02:00 PM.
10-12-2003, 12:28 PM
#3
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Join Date: May 2003
Location: KY
Posts: 5
That actually put it into perspective for me. Now I've got to do more research. Being a newbie at anything usually bites in the beginning, though it always fuels the desire to learn.
Thanks for the great response!
Thanks for the great response!
10-12-2003, 01:55 PM
#7
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Join Date: Oct 2002
Location: Upstate NY
Posts: 2,931
Originally posted by ExcessiveForce
OldStroker, I tried to send you a PM but it says your box is full. Mind if I email you or something?
OldStroker, I tried to send you a PM but it says your box is full. Mind if I email you or something?
I think I cleaned out some. email is fine.
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