Hemi Killer

iTrader: (6)

25,000 miles? It's a F13 cam (230/232-.595/585-114+4) in a forged 383. It's a daily driver and I don't beat on it too bad...

RAGENZ28

iTrader: (5)

Test the spring pressure, if it is still good drive it.

Shawn MacAnanny

iTrader: (12)

How do you test spring pressure?

brad8266

iTrader: (23)

I got like 20k in my dual springs with a similar cam, they are still fine.

Steve Bryant

iTrader: (1)

Give Gunnar a call at Patriot 888-462-8276 and he'll give you some guidelines.

Steve

bluehawk2

iTrader: (74)

I changed mine at 35k miles with a similar cam profile as yours. I changed them just for peace of mind. The car does seam to rev a little faster now. I would say that they still have some life left in them. If you are going to pull them off and test them, you might as well put some new ones on. JMO

Hemi Killer

iTrader: (6)

They've only got ~18,000 miles on them so far. I was planning on doing it this summer when it has 25,000 miles on it. I thought it would be ok, since the FMS/Cammotion lobes aren't as aggressive as the comp XER lobes.

allngn_c5

iTrader: (3)

If your lift numbers were over .600 you'd be changing them every 15k for piece of mind. Last thing you need on big cam car is valve float.

CashDudeHomie

iTrader: (5)

How often for a ~.550 cam IYO?

allngn_c5

iTrader: (3)

I am in no way the one to ask this. So I would refer you the manufacturer. The only thing I can give you is my personal exp. .600+ lift cams require extra attention. Thats the cost for the extra power. Nothing in life if free. If I had to guess you could probably get 50k easy. Isn't stock lift around .500 with durations of 203 or so, and c5 z's .525 and a few more degrees of duration. There valve springs seem to last forever. I know a few guys with c5's one with 97 with 129k on the clock, and the other a 98 with 100k. Both guys are bolt on only, never cracked into the motor, both run awesome, both make 350+ rwhp.

firefighting1101

iTrader: (48)

i dont know when exactly to change them, but i just bought a used set of patriot heads with "6k" miles on them and two of the inner valve springs on the dual springs were broken...so i probably wouldnt run them too long without checking them.

Shawn MacAnanny

iTrader: (12)

That happens when you run cams like mine

Ryan L

I think people get too paranoid about the double spring life. How many double spring failures have been documented on this site?

Shawn MacAnanny

iTrader: (12)

I broke a dual valve spring on a set of ET LS6 heads i had on my Z06. It broke at about 7k rpm with about 3500 miles on it (fully warmed up and all). Inner spring held didnt hurt my valves. ET sent me a brand new set of springs, retainters, seals, locks, free of charge no questions asked. That was with a 238/242 .608/.612 115lsa cam. I figure if a spring can break new, it can break at any time anywhere. Nothing was damaged, i even drove the car about 20 miles with the broken spring to a friend who replaced the springs for me. I think people are too paranoid about breaking springs, spinning bearings, and bending valves. I say what happens happens. It all costs money.

Ryan L

I may sound like a noob, but how did you know you broke the spring at the time?

Hemi Killer

iTrader: (6)

I'd like to know as well....

GuitsBoy

iTrader: (4)

I had 25K on a f13 cam, spring pressures were still near stock rates. Id say 25 - 30 is pretty safe. After that, might be worth replacing them. You can get just new coils without buying the whole kit.

Shawn MacAnanny

iTrader: (12)

When it broke it felt like i lost 60hp. Like i instantly felt it when it broke. I was in the top of probably 4th gear around 7k and when i shifted into 5th i knew right away i had no power. I slowed down watched my oil pressure and it was all fine. Got it home and heard the tapping. Found exactly where the tappin what coming from and pulled the valve cover, started it up, and found the broken spring.