Bought some new lunati dual valve spring for $100 on craigs list for my TR220 install, curious what their lifespan is on a dd that gets floored 3-20-times a tank. OR how many milesish till they should be swapped.

 

Double "Gold springs" last about 40,000 miles, but should be checked every 10k. Normal beehives should be replaced around 10k.

 

Are they new springs? You have to be careful with used springs.

Spring life really depends on how hard they are pushed. That means total lift, cam ramp rates etc. it's also been said that spring develop a memory over time. That means if they've been used with a cam and rocker combo that is good for .550 lift for 10k miles. .625 lift could easily break one early on even if the spring is 'rated' for .650.

Spring failure can be catastrophic and expensive... Hence why most on here down buy used springs.

 

spring are brand new, the guy I bought them from needed money and was selling out all his cam swap parts for his ls1....poor guy.

Great info, The cam lift is .581/.581 and the springs are good to .650. I have read something about them forming/mating to the cam design before, especially in older chevy motors

 

How do stock springs make it 200-300K miles? B/c the cam/lift is so low/easy on them?

 

Yup.

They can barely last a few weeks running against anything but stock sized/stock computer friendly camshafts.

 

When you say check them every 10k. How do you do that as in what to look for kinda thing?

 

X2
Check seat pressure?

 

Yes think about it like this; stock cam is 00-04 5.3= 191/190 .457/.466 114 lsa and it shifts at 5600rpm. A cam like the 212/218 .522/.529 lsa115 requires better springs even with stock shift points as the lift on the cam is 15% higher than stock. Now an aggressive cam such as a 224/228 .581/581 LSA112 and lift is already almost 30% higher than stock. However, lift isn't IMO what kills springs. It's more rpms healthy LSA and extreme duration that causes the spring to be compressed longer and open or close more quickly/violently. It's the same reason you don't use stock springs on a prerunner truck. You need stronger coil overs with good shocks. The difference between an aggressive cam lobe and a stock one is like the difference between driving 25mph down a bumpy dirt road and driving 50mph thru some whoops at the super cross track.

Seat pressure is most important and visual inspection looking for discoloration or anything out of the ordinary.
You got it. You want it close to when you put them in. However, just checking a couple is more than enough as long as they are consistant.

 

Thanks for the info. But how do you check seat pressure? I was trying to build a good dd on this issue but I'm second guessing that. Max lift on my cam is .562 springs are ls6 blue good to .570 on comp rpm lobes. That's what the sponsor recommended.