what does the valve reliefs in the pistons do?
01-03-2004, 02:36 PM
#2
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Valve reliefs in a piston make room for the valves so you dont have PtoV clearence issues. You can run some huge cam and not worry about if the valves will kiss the pistons. 
01-03-2004, 03:47 PM
#3
Originally Posted by Country Boy
Valve reliefs in a piston make room for the valves so you dont have PtoV clearence issues. You can run some huge cam and not worry about if the valves will kiss the pistons.
Also remember that valve reliefs mean a decrease in compression so make sure to check what compression you're pistons are rated at.....
josh
01-03-2004, 05:49 PM
#4
how much will valve relifes decress compression by? agostino racing built my block,do they set their blocks up to have the stock compression? my heads are also milled 30thousands. i want to switch to the g5x1 cam and was wondering if i could use this cam? agostino racing NEVER calls me back,and they really dont answer e-mails either,so i'm kinda in the blind about my motor?
03-02-2020, 08:32 AM
#5
the compression volume does not decrease, in fact it gets bigger due to this valve relief IN PISTON. Remember that when the piston is at TDC the valves are already closed so the valve are not using the space made in the piston.
Depending on the design of your piston you can have the following volumes
-Volume of piston bowl
-Volume of valve relief in piston
-some cases with a additional volume in the cylinder head
and if thereīs a squish height also must be considered
Depending on the design of your piston you can have the following volumes
-Volume of piston bowl
-Volume of valve relief in piston
-some cases with a additional volume in the cylinder head
and if thereīs a squish height also must be considered
03-02-2020, 03:49 PM
#7
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03-02-2020, 05:59 PM
#9
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the compression volume does not decrease, in fact it gets bigger due to this valve relief IN PISTON. Remember that when the piston is at TDC the valves are already closed so the valve are not using the space made in the piston.
Depending on the design of your piston you can have the following volumes
-Volume of piston bowl
-Volume of valve relief in piston
-some cases with a additional volume in the cylinder head
and if thereīs a squish height also must be considered
Depending on the design of your piston you can have the following volumes
-Volume of piston bowl
-Volume of valve relief in piston
-some cases with a additional volume in the cylinder head
and if thereīs a squish height also must be considered
03-08-2020, 06:44 PM
#14
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