Bought some Trick Flow heads that are on the low end of hydraulic roller cam compatible. The springs are 390 lbs/in, which is good, but installed at 1.900" with 120lbs seat pressure. This would make open pressure 354 lbs at 0.600" lift (not terribly concerned here). Coil bind is 1.100", so I have 0.800" to coil bind from current installed height.
Open pressure appears to be on the extremely low end of acceptable for a hydraulic roller cam. I think I want to throw a 0.060" shim under the spring to make seat pressure 143 lbs and open pressure 377 lbs. I will still have 0.740" to coil bind, which should be a good safe margin on a 0.600" lift cam
Anyone seeing any issues here?
Increasing seat and open pressures
Moderator: Team
Re: Increasing seat and open pressures
Issues, don't do it if you don't need to, guess it depends how gentle your closing ramps are as to whether you need to.
Ignorance leads to confidence more often than knowledge does.
Nah, I'm not leaving myself out of the ignorant brigade....at times.
Nah, I'm not leaving myself out of the ignorant brigade....at times.
Re: Increasing seat and open pressures
If it’s the 1.460” dual……..I do that all the time.
It’s a PAC-1903……..which is a drop-in replacement for the old Crane 99893 in many applications.
PAC lists it as a HR spring.
It’s a PAC-1903……..which is a drop-in replacement for the old Crane 99893 in many applications.
PAC lists it as a HR spring.
Somewhat handy with a die grinder.
-
mag2555
- Guru
- Posts: 4608
- Joined: Sun Sep 18, 2011 11:31 am
- Location: Heading for a bang up with Andromeda as we all are.
Re: Increasing seat and open pressures
Go right a head and put that .060” shim in, especially if the heads have not been run yet.
You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!
-
Warp Speed
- Guru
- Posts: 3285
- Joined: Wed Jun 25, 2008 1:46 pm
- Location: NC