I have a set of 918 valve springs on my car that have well over 20,000 miles on them and very many 1/4 miles trips (go to the track every weekend) When should you replce them i am going to pretty soon but i was just wondering.

 

Has any one had any problems with the new sets of 918 springs becuse it would be very easy for me to just replace them with out goign dual.

 

What cam? Personally I would change them ASAP with 20k miles. I learned the hard way..

 

Told ya so

As Vince said, he learned the hard way. 918's should be changed out every 15K IMHO because while being a decent spring, they are a SINGLE spring, so if one breaks it's potentially fatal to the motor. Reason being, it doesn't have an inner/outter spring to hold the valve up in the event of a break...

918's are cheap dude, 100 bucks and 2 hrs of your time are worth it..


josh

 

Depends on the cam. I plan to give mine about 50K with my useage habits and setup. I know a couple guys well past the 30K mark with no issues.

15K is a waste, IMO, for mild setups/rpms and mostly street use. It really all depends on the setup and useage though....

 

It is a tr 224

 

Rebuilding your shortblock because of a broken spring/dropped valve is more of a waste. For 100 bucks and two hours of time, I do not see taking safety measures to keep your motor alive being a waste...

JMO

Josh

 

I'm also using a stock timing chain. I'm not worried about that either.

I put my setup together without the intention of ever messing with springs again (at least not for a long, long time). That's why I chose a mildish cam, Ti retainers, stock valves, and no higher than 6300/6400rpm upshifts. Car sees no track time, all street miles. 50K should be no problem.