1.6 roller rockers on LB9 with stock cam
12-31-2011, 09:36 PM
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1.6 roller rockers on LB9 with stock cam
Alright, I've read quite a few threads and posts where members have used 1.6 roller tipped rockers on 305's with stock cams. What about valve springs? Will they work with the OE valve springs without issue? Is there really any noticeable gain with them or is it not worth the time? I'm only asking because I've got a complete LT4 hot cam kit that I was saving for my 350 roller motor.
BTW, the 305 in question is an '86 so its not a factory roller if that makes any difference whatsoever in cam lift.
BTW, the 305 in question is an '86 so its not a factory roller if that makes any difference whatsoever in cam lift.
01-01-2012, 12:43 PM
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Re: 1.6 roller rockers on LB9 with stock cam
You always should check clearances for interference when changing rocker ratios, but the LB9 camshaft is so small that you are unlikely to run into any issues at all with the install.
You should have no problem with the stock springs, but watch for interference where the pushrods go through the cylinder head.
Don't expect a large power gain from just the ratio change, - on the order of 10 hp, but don't expect more with all stock equipment.
Some people can install rockers and get a higher power gain, and some get no gain at all. That's not the fault of the rockers, but the fact that the installer has to reset the lifter pre-load during the installation procedure. Since people complete this procedure differently, you can get different results. Engines can respond differently to different amounts of lifter preload. I prefer to run as little preload as possible. If you check your factory set preload before the installation, you will probably measure quite a bit. You may wish to test the performance of your engine to see how it responds to different amounts of preload, either before or after the rocker installation.
If it is noticeable or worth the time is a completely subjective call for you to make.
You should have no problem with the stock springs, but watch for interference where the pushrods go through the cylinder head.
Don't expect a large power gain from just the ratio change, - on the order of 10 hp, but don't expect more with all stock equipment.
Some people can install rockers and get a higher power gain, and some get no gain at all. That's not the fault of the rockers, but the fact that the installer has to reset the lifter pre-load during the installation procedure. Since people complete this procedure differently, you can get different results. Engines can respond differently to different amounts of lifter preload. I prefer to run as little preload as possible. If you check your factory set preload before the installation, you will probably measure quite a bit. You may wish to test the performance of your engine to see how it responds to different amounts of preload, either before or after the rocker installation.
If it is noticeable or worth the time is a completely subjective call for you to make.
01-01-2012, 02:58 PM
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Car: '87 GTA Black/Black/Gold & others
Engine: TPI 350" & others
Transmission: Many
Axle/Gears: Many
Re: 1.6 roller rockers on LB9 with stock cam
.. There should be a slight gain, but if you're soon dropping the 350 in, it's prolly not worth the bother... especially if still running an all stock exhaust system...
Thanks for the replies. 
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