comp ratio, ran a calc?
#1
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comp ratio, ran a calc?
I have been getting everthing figured out for my build and have been real busy with work. I ran my numbers into a comprssion calc and came out with 12.2.1?
I have a stock spec 357 build (40 over bore, 3.48 stock crank). The crank has been turned .020, .027 headgasket, .014 milled off the heads (94 casting) no decking or anything done to the block aside the .040 bore. The piston is just as far in the hole as stock.
I thought i would be around 11.6.1 or 11.7.1? any help
I have a stock spec 357 build (40 over bore, 3.48 stock crank). The crank has been turned .020, .027 headgasket, .014 milled off the heads (94 casting) no decking or anything done to the block aside the .040 bore. The piston is just as far in the hole as stock.
I thought i would be around 11.6.1 or 11.7.1? any help
Last edited by slomarao; 10-10-2010 at 02:05 PM.
#3
Assuming about 5cc volume piston reliefs, stock deck height is usually around .025", you need to know your head cc's. I assume around 53cc being milled .014". You also need to know the bore size on the head gaskets, what gaskets are .027" thick? I know the Impala gaskets are .029" and 4.1" bore and the 1074 Felpro's are .026" thick with 4.125" bore.
So using the folowing:
'assumed' 5.0 cc valve relief volume for pistons
.027" thick, 4.1" bore head gasket
3.48" stroke
.025" deck height
53cc chamber volume
I get an 11.58:1 SCR
So using the folowing:
'assumed' 5.0 cc valve relief volume for pistons
.027" thick, 4.1" bore head gasket
3.48" stroke
.025" deck height
53cc chamber volume
I get an 11.58:1 SCR
#4
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Assuming about 5cc volume piston reliefs, stock deck height is usually around .025", you need to know your head cc's. I assume around 53cc being milled .014". You also need to know the bore size on the head gaskets, what gaskets are .027" thick? I know the Impala gaskets are .029" and 4.1" bore and the 1074 Felpro's are .026" thick with 4.125" bore.
So using the folowing:
'assumed' 5.0 cc valve relief volume for pistons
.027" thick, 4.1" bore head gasket
3.48" stroke
.025" deck height
53cc chamber volume
I get an 11.65:1 SCR
So using the folowing:
'assumed' 5.0 cc valve relief volume for pistons
.027" thick, 4.1" bore head gasket
3.48" stroke
.025" deck height
53cc chamber volume
I get an 11.65:1 SCR