petert 587 Posted July 4, 2006 After a fair amount of researching, I've finally found a set of double springs and retainers that are excellent value for money. Co-incidently, the Kawasaki Z900/Z1000 has 7mm valves and 7 degree collets, the same as the XU9J4/XU10J4. I had been looking at the APE's VSP500 double springs. Unfortunately these required a lower installed height of approx. 36mm, rather than 39mm like the Mi16. Then I discovered the VSP520 spring. They're designed for up to 0.520" lift, has 65 lbs. at 39mm and 200 lbs at 28.5mm. Judging by the surface condition, they appear to be a quality spring. And if they can withstand 9500+ rpm in drag bike racing, 8000+ should be a walk in the park. A pair weigh the same as an Mi16 single spring. When used with APE's titanium retainer, you save 8g. I also use the APE single groove collets with custom valves, but they'll work fine with the std. Mi16 collets. The only snag is that you'll need to get the spring base area of the head machined and fit hardened spring bases, the same as for any double spring installation. Check out the prices on the APE website, http://www.kzzone.com/cams.html, but you can do better from other suppliers. I'm going to write a program to churn out the spring bases. So if you want some let me know. Share this post Link to post Share on other sites
James_R 3 Posted July 5, 2006 would these also be suitable for s16 and GTi-6 valve trains aswell? Share this post Link to post Share on other sites
petert 587 Posted July 5, 2006 would these also be suitable for s16 and GTi-6 valve trains aswell? Definitely S16, they're identical to 1.9L Mi16. Not 100% sure on GTi6, but as they already have double springs they might be an easy upgrade. Share this post Link to post Share on other sites
16v205 9 Posted July 5, 2006 The valve stems in the gti-6 are 6mm, so thinner than mi16's. Rich Share this post Link to post Share on other sites
PumaRacing 2 Posted July 5, 2006 The only other snag being that the standard spring has 90lb at 39mm and 190 at 28.5mm so a lot less seat pressure, not much more full lift pressure and having to machine the head to boot. Rather a waste of time no? Share this post Link to post Share on other sites
205freak 7 1 Cars Posted July 5, 2006 and for the 205GTi 1.6?? what do you thing?? Share this post Link to post Share on other sites
petert 587 Posted July 5, 2006 The only other snag being that the standard spring has 90lb at 39mm and 190 at 28.5mm so a lot less seat pressure, not much more full lift pressure and having to machine the head to boot. Rather a waste of time no? Have you calibrated your spring tester lately? All the Mi16 springs I've tested are lucky to crack 80lbs @ 39mm. Sad springs pull 65, good ones 75-80. It's not a waste of time as you can then shim them up to what ever you want. The other point is you're hardly going to run this setup with hydraulic lifters. I'm more inclined to run less lbs. than more with solids, especially if you've reduced some mass somewhere. I have to admit it's not a mod. for joe average. Share this post Link to post Share on other sites
petert 587 Posted July 5, 2006 and for the 205GTi 1.6?? what do you thing?? Puma has his own solution for the 8V, but my favourite are the Crow Datsun L4 springs. I guess it all depends on local availability. Share this post Link to post Share on other sites
