spring longevity with big cam in autoX/RR?
Thread Starter
Joined: Nov 2001
Posts: 1,794
Likes: 1
From: Slate Hill, NY
spring longevity with big cam in autoX/RR? would these newer cams like LG's last 20k miles if you get double springs?
big lift, big duration.
i'm concerned about it because in drag racing, shouldn't be a big deal, but in autoX and RR, the RPM's are in the upper ranges for long amounts of time. puts a strain on the valvetrain. any dangers?
big lift, big duration.
i'm concerned about it because in drag racing, shouldn't be a big deal, but in autoX and RR, the RPM's are in the upper ranges for long amounts of time. puts a strain on the valvetrain. any dangers?
From what I've learned, double springs won't necessarily last longer than a good set of single behive springs like Comp 918's. The double springs are much heavier, which doesn't help either. With those really high lift cams, you will need to replace the springs every year no mater how you drive the car anyway.
Thread Starter
Joined: Nov 2001
Posts: 1,794
Likes: 1
From: Slate Hill, NY
thanx cal. i have a mild cam, B1, with 918's. they have been in for two years, 20k miles. i'll replace them soon. but i was thinking that the new crop of huge cams won't be able to last half that time with 918's. i autocross 2-3 times per month and these 918's are doing great (knock on wood).
Launching!
Joined: Dec 2001
Posts: 250
Likes: 0
From: Indiana
I'm not sure where you guys are getting this info. This is not intended as a flame or anything, but I have the G5X2 and have had it in the car for the last 30K miles with the REV dual springs. I have had 0 problems with this set up. I am not necessarily gentle on my motor as I do like to Auto-X as well as Drag Race pretty regularly. Not to mention the many miles of lightly traveled straight backroads blasts on my way to and from school. The springs are holding up great. As long as you let them get warm before you beat on it it doesn't seem to be much of a problem at all. Now am I saying that the springs will last forever? Not at all. I plan on pulling the springs here in the next couple months or so to have them checked to ensure they are applying the correct ammount of pressure to keep the valves safe. If they have faded at all (which I don't really think they have as the car runs great) I will replace them. It's a pretty cheap and simple insurance for the valves anyway.
Just my $.02
Just my $.02
RutanZ28, encouraging to hear your good record with valve springs on a high-lift cam. I'm also wondering how many of the people that've had problems were really reving the engine with cold springs. BTW, does your screen name have any conection with Burt Rutan of Scaled Composites and VariEasy Kitplane fame?
