pelensky

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?

Fazz73jr

iTrader: (3)

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.

pelensky

Do you know the specs on those springs?

Wicked94Z

iTrader: (26)

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.

wrd1972

iTrader: (12)

I have never had any luck with beehives on the XFI lobes. Always a float condition. I like a decent dual sping like the Patriot golds or extremes.

spudnick3119

I run the Patriot Golds in my car. I have the limiter set to 6400 and it pulls good all the way through. I haven't dynoed it yet to confirm no valve float though.

99Bluz28

iTrader: (35)

New Comp 918's are good for .625" lift, PAC 1518 are good for 650" lift, either one will be more then enough spring for .576" lift cam as long as the seat load height is set correctly.

Wicked94Z

iTrader: (26)

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.

joelster

DING! Winner!

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.

pelensky

Nice Firehawk. Makes me miss my 95 hawk.

What heads do you have and what part number Patriot Golds do you use? How are they set up (install height and preload)?

Wicked94Z

iTrader: (26)

I run mine down at .030 from coilbind. I'll probably run this next iteration down at .015-.020 to account for deflection in the valvetrain, at 7000+ rpm.