If you have a 280xfi cam, what springs do you use?
#1
If you have a 280xfi cam, what springs do you use?
I currently have 986-16 comp cam springs and the valves float at about 5400 RPM (I run the engine to about 6200 maybe 6300 max). This started only after a few thousands miles and a few years old.
I want to change them without changing the valves or rods but I need more springs. I currently have stock ported heads.
What springs are you running and what RPM do you run? How many miles and are you sure your valves don't float?
I want to change them without changing the valves or rods but I need more springs. I currently have stock ported heads.
What springs are you running and what RPM do you run? How many miles and are you sure your valves don't float?
#2
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From: Fontana, Ca
Pac golds that came with my le3 heads with titanium retainers. Rev her to 6700 and doesn't feel like I get valve float, but I haven't dyno'd it yet so IDK. I have summit aluminum 1.6rr, ls7 lifters, and trick flow push rods.
#3
#4
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I'll have some good used PAC 1518 springs, retainers, and seats FS here pretty shortly. Less than 2000 easy street miles on these springs and 5 1/8 mile passes. These are a very high quality spring. You can set them up at 1.73 or so and you'll be at 155 seated 330+ open.
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#8
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using my little beehives on a solid roller lobe, that's fatter than an XFI lobe and .382 lobe lift, I spin 7100 rpm. You have to set them up right up on coilbind to cut down on the harmonics, use a good pushrod and good geometry.
Still going to use a beehive on my next setup, a fat lobe'd 255/263 .640/.640 that will do over 7000 rpm. Using a titanium retainer on that setup though.
Still going to use a beehive on my next setup, a fat lobe'd 255/263 .640/.640 that will do over 7000 rpm. Using a titanium retainer on that setup though.
#9
using my little beehives on a solid roller lobe, that's fatter than an XFI lobe and .382 lobe lift, I spin 7100 rpm. You have to set them up right up on coilbind to cut down on the harmonics, use a good pushrod and good geometry.
Still going to use a beehive on my next setup, a fat lobe'd 255/263 .640/.640 that will do over 7000 rpm. Using a titanium retainer on that setup though.
Still going to use a beehive on my next setup, a fat lobe'd 255/263 .640/.640 that will do over 7000 rpm. Using a titanium retainer on that setup though.
I run the bigger XFI468 and run 918 beehives. Zero issues. I shift at 67-6800rpm all the time. When we installed the springs on my TFS heads, my friend put in a solid lifter and rotated it through a cycle checking for coil bind. It was too close for his liking. He made me overnight a special set of locks that raise the retainer just a touch. After we put the new locks in everything was in spec. I had to get a set of chromoly pushrods in .10" longer to get the geometry just right. Then we set the lash perfect, to 1/8th of a turn past zero lash. All of these things are critical. People have problems and then blame the cam and springs when it was 100% user error on the install that is the culprit.
#10
What heads do you have and what part number Patriot Golds do you use? How are they set up (install height and preload)?