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can somebody school me on this ??

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Old Dec 13, 2005 | 09:33 AM
  #1  
95_z28_4_Ivan's Avatar
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From: Cali...
can somebody school me on this ??

Ok so the high perfomance topic is all new to me, and I had a cople of questions that I was hoping you guys could clear for me.

When someone ask "What's the Bore" what are they looking for??
I did some reading and I not sure if I'm on the right track or not, but is that asking for the size of the cylinder and/or piston?? (I apologized if this sounds like an ignorant question)

Or when you're looking at pistons & it's asking for "CID" 383 385 388. Does this somehow relate to the Bore???? what's the cid on a 95 lt 1?? and or maximum bore??

I'm @ work so I try to read in between calls, so if you guys could clear that up for me, I'd really appreciate it...
Old Dec 13, 2005 | 09:42 AM
  #2  
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Re: can somebody school me on this ??

bore is the diameter of the cylinder

stroke is how far the piston moves up and down in the cylinder

you use both to determine displacement....350, 383, 396 etc

displacement = [3.14 x (bore/2)^2] x stroke x (number of cylinders)

so if bore is 4", stroke is 4"

displacement is (3.14)x(2)^2 x 4 x 8 = 402ci
Old Dec 13, 2005 | 09:45 AM
  #3  
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Re: can somebody school me on this ??

standard chevy 350 has a bore of 4.00" and stroke of 3.48"

355 when you hone the cylinders out to a wider diameter. 4.030" with the 3.48" stroke

383 is increased bore and increased stroke, 4.030" bore and 3.75" stroke
Old Dec 13, 2005 | 09:50 AM
  #4  
OBE1 95Z28's Avatar
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Re: can somebody school me on this ??

A stock LT1 came with a 4" bore and a 3.48" stroke and is approximately a 350 ci. When an engine is rebuilt, you usually need to slightly increase the bore to "clean-up" the cylinder walls. The bore can be enlarged as little as
.010", but it's common for people to open the bore .030". This now creates a 355 ci engine (same stroke as before). If the crankshaft is replaced with a stroker crank (3.75" stroke) and the cylinders are bored .030", then you end up with a 383.
Old Dec 13, 2005 | 09:56 AM
  #5  
95_z28_4_Ivan's Avatar
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From: Cali...
Re: can somebody school me on this ??

Originally Posted by teke184
bore is the diameter of the cylinder

stroke is how far the piston moves up and down in the cylinder

you use both to determine displacement....350, 383, 396 etc

displacement = [3.14 x (bore/2)^2] x stroke x (number of cylinders)

so if bore is 4", stroke is 4"

displacement is (3.14)x(2)^2 x 4 x 8 = 402ci
So would I bennefit by having wider cylinder?? is there any ups & downs of this upgrade??
Old Dec 13, 2005 | 09:59 AM
  #6  
95_z28_4_Ivan's Avatar
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Re: can somebody school me on this ??

Originally Posted by OBE1 95Z28
A stock LT1 came with a 4" bore and a 3.48" stroke and is approximately a 350 ci. When an engine is rebuilt, you usually need to slightly increase the bore to "clean-up" the cylinder walls. The bore can be enlarged as little as
.010", but it's common for people to open the bore .030". This now creates a 355 ci engine (same stroke as before). If the crankshaft is replaced with a stroker crank (3.75" stroke) and the cylinders are bored .030", then you end up with a 383.

so the bore can be increase as little as .010 . what would be the max bore on a lt1 and do you suggest this if I'm rebuilding the engine??
Old Dec 13, 2005 | 11:04 AM
  #7  
teke184's Avatar
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Re: can somebody school me on this ??

not sure what the max bore is, but typically you dont see much over .060"

that would make a standard 383 LT1 into a 388ci.

you can get pretty radical with the bore/stroke to make over 400ci on LT1s...buy it's very $$$$$

as stated the cylinders are usually honed or bored out...to clean the walls up for better ring sealing. just increasing the diameter of the bore doesn't do that much for performance if everything else is rebuilt stock.

what are you trying to get out of your car? what reasons do you have for rebuilding?

if it's just to freshen up the motor than the standard +.030" should be fine.

if you want more power, you'll have to pay for better components.
Old Dec 13, 2005 | 11:20 AM
  #8  
95_z28_4_Ivan's Avatar
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From: Cali...
Re: can somebody school me on this ??

Originally Posted by teke184
not sure what the max bore is, but typically you dont see much over .060"

that would make a standard 383 LT1 into a 388ci.

you can get pretty radical with the bore/stroke to make over 400ci on LT1s...buy it's very $$$$$

as stated the cylinders are usually honed or bored out...to clean the walls up for better ring sealing. just increasing the diameter of the bore doesn't do that much for performance if everything else is rebuilt stock.

what are you trying to get out of your car? what reasons do you have for rebuilding?

if it's just to freshen up the motor than the standard +.030" should be fine.

if you want more power, you'll have to pay for better components.


Well my car has 170K miles on it, and I was thinking about rebuilding the engine in a month of so, but I blew a head gasket over the weekend & the car is at the shop, engine is down, so I aksed my self what else could I do to the engine since it's down. I had a mejor oil leak also, but aparently that's not going to be a problem after I replace all the gaskets (according to the mechanic). so now that you know my situation what would you suggest ??
new pistons?? .030 bore ??
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