Rockers W/O Hi Cat
#11
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With 1.9 reworked stock rockers stock springs are fine as long as shift points are 5800 RPM and lower. This isn't a big deal since until you do some bigger mods shifting at a higher RPM will not help much.
Here is a good article on rockers, springs, retainers, etc.
http://www.zzperformance.com/grand_p...les1.php?id=53
Here is a good article on rockers, springs, retainers, etc.
http://www.zzperformance.com/grand_p...les1.php?id=53
#12
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1.9 Rockers make power up to 6000. Shifting earlier than this negates the extra power 1.9s can give you as unlike cams they do not broaden the entire powerband only the upper part (higher rpm). You can certainly run stock springs with any ratio rocker if you only turn the motor to 5600-5800 but again your wasting potential.
#13
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Using a modified 1.9 ratio rocker without changing the valve springs works well because the stock springs are light and you don’t get much rocker deflection. You do risk valve float this way but most people don’t have that problem.
Then when I have a look at the modified rockers on the website, I see this.
Limited production of 1.9 modified rocker arms. Due to customer requests, we ran a few sets of modified rocker arms.
These started out as a stock rocker arms. The seats have been welded in and remachined at a new location to achieve a ratio of 1.9 (vs. the stock 1.6). There are hundreds of this style of rocker arm in the 3800 market, all with excellent results.
These work with all stock or aftermarket pushrods, lifters, springs, retainers. They will not work with aftermarket cams. Aftermarket springs are recommended for shift points over 6100.
These started out as a stock rocker arms. The seats have been welded in and remachined at a new location to achieve a ratio of 1.9 (vs. the stock 1.6). There are hundreds of this style of rocker arm in the 3800 market, all with excellent results.
These work with all stock or aftermarket pushrods, lifters, springs, retainers. They will not work with aftermarket cams. Aftermarket springs are recommended for shift points over 6100.
#14
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5800RPM is safe... their are other factors that will effect when you get valve float. Some people have been able to run 6000RPM and higher no problem. I don't think that shifting over 6000RPM is worth $180+, a harder install, and a timing chain dampener that is going to wear out faster.
#15
Originally Posted by fantastic88
So, you guys say 6000rpm needs new springs. ZZP says 6100rpm or lower does not. Why the contradiction? :?
I say change out the valve springs, that way you won't have any doubt.
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Originally Posted by fantastic88
Using a modified 1.9 ratio rocker without changing the valve springs works well because the stock springs are light and you don’t get much rocker deflection. You do risk valve float this way but most people don’t have that problem.
Then when I have a look at the modified rockers on the website, I see this.
Limited production of 1.9 modified rocker arms. Due to customer requests, we ran a few sets of modified rocker arms.
These started out as a stock rocker arms. The seats have been welded in and remachined at a new location to achieve a ratio of 1.9 (vs. the stock 1.6). There are hundreds of this style of rocker arm in the 3800 market, all with excellent results.
These work with all stock or aftermarket pushrods, lifters, springs, retainers. They will not work with aftermarket cams. Aftermarket springs are recommended for shift points over 6100.
These started out as a stock rocker arms. The seats have been welded in and remachined at a new location to achieve a ratio of 1.9 (vs. the stock 1.6). There are hundreds of this style of rocker arm in the 3800 market, all with excellent results.
These work with all stock or aftermarket pushrods, lifters, springs, retainers. They will not work with aftermarket cams. Aftermarket springs are recommended for shift points over 6100.
We also have stock springs in the Monte Carlo and it has 1.9'* and we haven't had any valve float problems with that car either. All cars are different. When we had 1.9'* in the GTP before we put the springs in it it had valve float like crazy and the car only had ~12k miles on it.
Shawn
#17
I noticed your Olds is a 97. Mine is a 97 too, so we should have the same kind of heads on our engines. From what I hear, the 97'* have a slightly different design that doesn't allow the 90lb springs to fit properly.
This is what has held me back from getting 1.9'*.
Some other forums have a lot of info about the 97 heads, just thought youd wanna know.
This is what has held me back from getting 1.9'*.
Some other forums have a lot of info about the 97 heads, just thought youd wanna know.
#18
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Originally Posted by Sol
I noticed your Olds is a 97. Mine is a 97 too, so we should have the same kind of heads on our engines. From what I hear, the 97'* have a slightly different design that doesn't allow the 90lb springs to fit properly.
This is what has held me back from getting 1.9'*.
Some other forums have a lot of info about the 97 heads, just thought youd wanna know.
This is what has held me back from getting 1.9'*.
Some other forums have a lot of info about the 97 heads, just thought youd wanna know.
#19
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105# Compcams will and would allow you to run 1.9'* no problem.