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what does the valve reliefs in the pistons do?

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Old Jan 3, 2004 | 02:16 PM
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Default what does the valve reliefs in the pistons do?

i have ross flat top pistons with valve reliefs,what does this mean? what do they do? i also have my heads milled .030-thou,does the valve reliefs to anything to this? THANKS,mike c.
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Old Jan 3, 2004 | 02:36 PM
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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.
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Old Jan 3, 2004 | 03:47 PM
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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
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Old Jan 3, 2004 | 05:49 PM
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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?
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Old Mar 2, 2020 | 08:32 AM
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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 there´s a squish height also must be considered
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Old Mar 2, 2020 | 08:51 AM
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How do you dig up a 16 year old post?
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Old Mar 2, 2020 | 03:49 PM
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Originally Posted by RonSSNova
How do you dig up a 16 year old post?
By being a new first-poster who does not CHECK POST DATES.
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Old Mar 2, 2020 | 03:59 PM
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Originally Posted by G Atsma
By being a new first-poster who does not CHECK POST DATES.
Nah he's a spammer, gonna start selling us chinese made parts soon.
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Old Mar 2, 2020 | 05:59 PM
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Originally Posted by ii2 GT
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 there´s a squish height also must be considered
Do what?
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Old Mar 2, 2020 | 07:41 PM
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Originally Posted by Che70velle
Do what?
My thoughts exactly lol
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Old Mar 3, 2020 | 06:04 PM
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About ii2 GT
Country of Residence DE <<<<< Hunter Biden's illegitimate son?
Gender Male
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Old Mar 8, 2020 | 10:49 AM
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yes! I live in Germany.
No, I´m not a spammer I´m just a student who was searching for info and goggle brought me here
yeah! I didn´t check the post´s date
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Old Mar 8, 2020 | 06:35 PM
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Originally Posted by G Atsma
By being a new first-poster who does not CHECK POST DATES.
Very few.....you are one of the few to make it their job in life to tell them.

#notallheroswearcapes
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Old Mar 8, 2020 | 06:44 PM
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Originally Posted by LilJayV10
Very few.....you are one of the few to make it their job in life to tell them.

#notallheroswearcapes
I calls them when I sees them....
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