Quote:
Originally Posted by chuckies76ta
Tim: How's the retainer fitting against the spring inner and outer? Especially the inner. My understanding is the inner spring is .100 shorter than the outer.
I'm curious. What is the height of all your valves from the spring pad to the upper side of the retainer with no shims under the spring pad using your Micrometer? So that would be your installed height to start with. I understand your suppose to pick the shortest one and work from there.
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Chuck
First off Bullet Cams knowing Ultradyne cams and having specific knowledge of my cam recommended the PAC 1243 springs installed at 1.85 with 1.65 rockers. Bullet also said .070 is the ideal distance from coil bind. After accounting for the .016 lash I have .085 distance from coil bind at net lift. I didn't calculate the distance from coil bind based on what PAC says it is supposed to be I measured it.
The retainers fit correctly, they are stepped to account for the shorter inner spring. I don't like to put the springs directly on the head and/or the shims as it tears things up and the springs can move around. I am using a hat style spring locator and shims are installed under the spring locator.
Installed height with spring locator installed is between 1.826 to 1.840 on the exhaust and between 1.885 and 1.898 on the intake. I am using -.050 retainer locks on the exhaust valves so that I can meet the 1.85 installed height on the exhaust valves.
I am fine with the open and closed pressures provided the PAC springs have meet the pressure they advertise. My issue is some of the the new PAC 1243 springs I have do not meet the correct pressure at 1.85. The pressure at should be in the 265 neighborhood but the pressures are all over the place ranging from 220 to 272. The spring rate is inconsistent and not correct for about 40% of the springs because they look pretty good at full lift but on the seat not so much.
I was looking at the Comp 943 springs and may exchange the PAC springs for the comp's. If I got another set of the PAC's I probably would end up with the same issue.