- Apr 18, 2006
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Well, this is another random tech article. Its not really a big thing since nobody installs their own vavlesprings, but here are some stuff I learned.
Valvesprings usually has its own spec sheet, they are not usually published online, but you can request them from the manufacturer. Most US valvespring makers have them on request.
Terminology you need to know.
installed height:
This is how tall the valve springs are after they are installed. The install height is different due to the valve seats. usually there is a small difference. as long as its within 0.5mm, shouldn't matter much.
why is it important:
the installed height preloads the spring, this gives you "seat pressure" that means how hard your valves press on the valve seats.
seat pressure:
This is how hard the valves press on the valveseats. For lastability, we don't want it very high, because it stresses the valvestems. but for turbos, we want it high enough so that it will close properly against the flow of air rushing in from a turbo or supercharger. We can't really change this springs to spec, but we can change valves seats and grind them to get the seat pressure we want. The springs specs usually have seat pressure vs install height table. Too high, and you risk breaking your valves even if you have good clearance.
coil bind limit:
this is usually the limit where the valvesprings bind. Means if you compress it past this limit, it wont return back to its original height. Most aftermarket honda is 19mm+, but take this with a pinch of salt, the older and worn out the springs, this number is reduced a lot.
Thats all I remember for now, its something to pay attention to if you run aftermarket cams. They are WEAR & TEAR items and need to be replaced from time to time.
Sent from my GT-I9100G using Tapatalk 2
Valvesprings usually has its own spec sheet, they are not usually published online, but you can request them from the manufacturer. Most US valvespring makers have them on request.
Terminology you need to know.
installed height:
This is how tall the valve springs are after they are installed. The install height is different due to the valve seats. usually there is a small difference. as long as its within 0.5mm, shouldn't matter much.
why is it important:
the installed height preloads the spring, this gives you "seat pressure" that means how hard your valves press on the valve seats.
seat pressure:
This is how hard the valves press on the valveseats. For lastability, we don't want it very high, because it stresses the valvestems. but for turbos, we want it high enough so that it will close properly against the flow of air rushing in from a turbo or supercharger. We can't really change this springs to spec, but we can change valves seats and grind them to get the seat pressure we want. The springs specs usually have seat pressure vs install height table. Too high, and you risk breaking your valves even if you have good clearance.
coil bind limit:
this is usually the limit where the valvesprings bind. Means if you compress it past this limit, it wont return back to its original height. Most aftermarket honda is 19mm+, but take this with a pinch of salt, the older and worn out the springs, this number is reduced a lot.
Thats all I remember for now, its something to pay attention to if you run aftermarket cams. They are WEAR & TEAR items and need to be replaced from time to time.
Sent from my GT-I9100G using Tapatalk 2