Robby1870 Posted April 13, 2003 Report Posted April 13, 2003 Okay, guys, hope you all know a lot about the 3.1Ls stock valve springs. How much TOTAL valve lift can the stock springs take? I have heard .420", but I wanna know for sure. Also, what is the coil bind limit for the stock springs? I have done some calculating, and the 1.6:1 ratio rocker arms I want are gonna give me the following, TOTAL valve lifts: .420" intake and .437" exhaust. If the stock springs dont work, I have found some performance replacements from GM parts direct. I have sent basically the same question to them too, cuz I want to be sure I do this right. If anyone has any knowledge about this or would know where to get definite answers let me know. Thanks for any help Robby Quote
Robby1870 Posted April 14, 2003 Author Report Posted April 14, 2003 stock cam, just doing the rocker arm upgrade Robby Quote
Brian P Posted April 14, 2003 Report Posted April 14, 2003 You'll be absolutely fine. I have 1.6's on my car, plus I know people that run aftermarket cams on stock springs with no problems Quote
Robby1870 Posted April 14, 2003 Author Report Posted April 14, 2003 how long have you had them on? And, how much power did you see from them? Noticeable? I heard 10-30HP, depending on other mods Robby Quote
Brian P Posted April 14, 2003 Report Posted April 14, 2003 Been about 4 mos, I cant see getting any more than 10hp max on a stock motor. driveability, the engine gets up to speed faster and responds better at higher RPM's, might benefit better with a cone filter. That's why Ive been pricing cones. DOnt know if it'll work or not Quote
Robby1870 Posted April 14, 2003 Author Report Posted April 14, 2003 Cool, I really didnt want to get into the valve springs if I didnt have to. I mean I could do it, but it would take alot longer. Yeah, I couldnt see more than 10HP on a stock motor either. Hopefully with my exhaust and cut open air box and K&N, I'll see more. How long did the install take you? Prolly not too long, its not very involved. Im hoping over the summer, I can do it on a Saturday. If I was going to have to do the springs it was going to take me a lot longer. Yours are on a 3.1L right? Cuz I have heard that on my motor, the rocker studs are non-adjustable, and they need to be for the 1.6 rockers. 2.8s all had the adjustable studs, so I may have to get the studs from a 2.8, thats cheap though. Robby Quote
Brian P Posted April 14, 2003 Report Posted April 14, 2003 You'd need studs from a gen 1 2.8, usually like Camaros and old 80s J-bodies. As to the entire job, you're in for a treat, cause on the 3.1 the rockers dont all come out after the valve covers are removed. The whole intake manifold set has to be removed because it gets in the way of a few of them. Quote
Robby1870 Posted April 14, 2003 Author Report Posted April 14, 2003 Damn, both manifolds. That means, injectors, fuel rails......son of a bitch! Did you tilt the motor to reach the rear ones? Im assuming you did. Robby Quote
Brian P Posted April 14, 2003 Report Posted April 14, 2003 you bet!! I don't know if anyone actually got all the rockers out without removing the manifolds, but I couldnt and my friend with a 91 3.1 couldnt either. The manifold is *slightly* in the way, it sucks balls. No problems on the 3100 though! Quote
Robby1870 Posted April 14, 2003 Author Report Posted April 14, 2003 Damn, that really sucks. Im going to assume that my rocker studs and the ones I need are screw in, am I right? They woul have to be, for the ones I need to be adjustable Robby Quote
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