VALVE SPRINGS
05-26-2003, 08:24 PM
#1
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VALVE SPRINGS
has anyone ever replaced their valve springs with a larger dia and higher spring pressure valve springs. i checked and my stock spring dia. is 1.230" but the spring seat is machined larger. i have been thinking about going to a small block chevy valve spring that is 1.255" in dia. but the installed pressure goes from 74-85 psi to like 105psi or maybe even 135 psi. i honestly feel that this is what limits us to a 5500 rpm redline. plus when racing, the springs take a pounding, this will allow the valves to close fasterallowing a higher rpm to be reached.
any input on this topic :?:
any input on this topic :?:
05-27-2003, 07:54 AM
#2
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The L36 and L67 get a lot of valve float up in the higher end if you don't change to a higher rate of spring. If you are going to be racing a good deal, then I would recommend the new springs. It seems as though you have done some good measurements for the new ones, so they shouldn't be an issue. Just watch for the retainers. You'll need larger ones and the Chevy'* may not fit our valves.
Some of the 3800 parts sites carry higher-rate springs designed for our cars. You might want to check those out first before running the Chevy'*. I'm sure the prices are a tad bit higher, but the expense is worth it. I will be doing this sometime this summer as I get ready to install my Procharger.
Some of the 3800 parts sites carry higher-rate springs designed for our cars. You might want to check those out first before running the Chevy'*. I'm sure the prices are a tad bit higher, but the expense is worth it. I will be doing this sometime this summer as I get ready to install my Procharger.
06-02-2003, 09:51 PM
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More info can be found on my rebuild post but I talked to my shop guy about this and he suggested a shim and proved the difference to me. Go check out my post for more info.
06-02-2003, 10:27 PM
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Yes, the valve springs are pretty much what limits the redline on our engines. The stock ones are crappy, like 65lb. You can buy 105'* and 135'* for the series II, but I believe they are the same on the series 1'*. Not only are the stock springs weak, but they wear out real quick with some hard driving. My dad when he started modding at 15,000 miles got no valve float at all. He got his rockers, pushrods, and DHP (which shifts @ 6200 rpms, redline on stock L67 is 6000) and still got no valve float with stock springs. He put everything on his car that is on it now (mods in sig), between 15,000 and the now 18,000 miles. Just this past week the car has started to get noticable valve float, which it did not have before. It looks like we are going to be upgrading to stronger springs and retainers. Then maybe get the shift points raised to like 6400 or so, but we may just leave them the same (6200) seeing it still has the stock cam.
06-03-2003, 12:11 AM
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Yes, the valve springs are pretty much what limits the redline on our engines. The stock ones are crappy, like 65lb. You can buy 105'* and 135'* for the series II, but I believe they are the same on the series 1'*. Not only are the stock springs weak, but they wear out real quick with some hard driving. My dad when he started modding at 15,000 miles got no valve float at all. He got his rockers, pushrods, and DHP (which shifts @ 6200 rpms, redline on stock L67 is 6000) and still got no valve float with stock springs. He put everything on his car that is on it now (mods in sig), between 15,000 and the now 18,000 miles. Just this past week the car has started to get noticable valve float, which it did not have before. It looks like we are going to be upgrading to stronger springs and retainers. Then maybe get the shift points raised to like 6400 or so, but we may just leave them the same (6200) seeing it still has the stock cam.
The springs should be done at the same time.
The only downside is he may have to go back to stock rocker ratio due to the higher lift cam
06-03-2003, 07:51 AM
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If he goes with a mild cam he should be ok. You can to almost .515 lift with these engines and not get a problem. Your MPG will be shyte, but it'll run like the devil!
06-09-2003, 02:46 PM
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If anybodys interested I have a set of Comp Cams 130lbs springs. Only thing you would need are LS1 retainers. These have about 200miles on them and are the same one sold at Intense-racing.com
I can send pics if anybodys interested- jjh4296@msn.com
I can send pics if anybodys interested- jjh4296@msn.com
06-09-2003, 07:45 PM
#10
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they only fit series 2 motors. i just installed small block chev springs today in my series 1. stock are like 74 lbs @ 1.750" . the ones i installed are 110lbs@ 1.750". direct fit too. the difference in series 1 and series 2 springs and valves are.
series 1.......... 11/32" valve stems and cylinder shaped springs
series 2.......... 7mm valve stem dia. and beehive style springs
series 1.......... 11/32" valve stems and cylinder shaped springs
series 2.......... 7mm valve stem dia. and beehive style springs
