While I was spending the time to port all of the oil passages in my front cover, I got to thinking about the filter bypass valve. So I ground off the stakes holding the plunger in the filter adapter and took it apart. I measured it up the spring and got the following.
Wire diameter = .034"
Spring diameter = .483"
Active coils = 6
I used this to calculate the spring constant of 7.4123
I went on measuring the free and installed height of the spring and calculated the spring pressure with the valve seated
Free height = 1.115"
Installed height = .805"
Calculated seat pressure = 2.2978 lbs.
The bypass port is .385" in diameter giving it an area of .116 square inches
2.2978 lbs divided by .116 square inches gave me a 19.8 psi
I believe I read somewhere the the factory bypass valve opens at 20 psi so that showed me the my math is accurate enough.
Now what all this is leading up to is a way to change the pressure that the bypass valve begins to open. I have decided that I do not want to block off the bypass because of the possible issues with blowing apart oil filters. I would however like to raise the pressure that the bypass opens. I'm thinking that I will target around 70 psi as that will be the max I suspect the engine see under normal conditions. That will give me filtered oil at all times but still allow excess pressure to bleed off during cold starts. With the above calcs I should be able to accurately determine the spring I need to do this.
Has anyone done this before or have any other input as to what pressure I should target as the bypass cracking pressure?
Wire diameter = .034"
Spring diameter = .483"
Active coils = 6
I used this to calculate the spring constant of 7.4123
I went on measuring the free and installed height of the spring and calculated the spring pressure with the valve seated
Free height = 1.115"
Installed height = .805"
Calculated seat pressure = 2.2978 lbs.
The bypass port is .385" in diameter giving it an area of .116 square inches
2.2978 lbs divided by .116 square inches gave me a 19.8 psi
I believe I read somewhere the the factory bypass valve opens at 20 psi so that showed me the my math is accurate enough.
Now what all this is leading up to is a way to change the pressure that the bypass valve begins to open. I have decided that I do not want to block off the bypass because of the possible issues with blowing apart oil filters. I would however like to raise the pressure that the bypass opens. I'm thinking that I will target around 70 psi as that will be the max I suspect the engine see under normal conditions. That will give me filtered oil at all times but still allow excess pressure to bleed off during cold starts. With the above calcs I should be able to accurately determine the spring I need to do this.
Has anyone done this before or have any other input as to what pressure I should target as the bypass cracking pressure?