Roller Rocker Opinions Please
Thread Starter
Instructor
Joined: Jan 2002
Posts: 104
Likes: 1
From: Gainesville FL
Roller Rocker Opinions Please
I don't know much about roller rockers other than a 1.6:1 ratio may be better than a 1.5:1 ratio. I am basically looking for information on what I should or should not do or possibly a link to a good source of information to educate myself.
What I had in mind is installing gm part# 12370839 (used in the LT4) in my LT1 as described in the following link: http://www.westol.com/~brettd/corvette/rocker.html It looks and is desribed easy enough to do, is there a catch? Would I have to do anything else besides unbold the existing ones and properly torque in the new ones? Is it worth the $273.00?
What I had in mind is installing gm part# 12370839 (used in the LT4) in my LT1 as described in the following link: http://www.westol.com/~brettd/corvette/rocker.html It looks and is desribed easy enough to do, is there a catch? Would I have to do anything else besides unbold the existing ones and properly torque in the new ones? Is it worth the $273.00?
Race Director
Joined: Jan 2002
Posts: 12,263
Likes: 86
From: O'Fallon Missouri
Re: Roller Rocker Opinions Please (Lichen_1)
Those GMPP rockers will work just fine. I am running Crane Gold 1.6's (Crane makes the GMPP rockers) 0n my 94. The RR's really makes the engine rev smoother, especially above 5000rpms.
You will need to cut off the oil drip tabs off on the inside of the valve covers to make space for the larger rockers. Also, you should change valve springs to the LT4 springs, the LT1 springs will be really close to coil bind with the 1.6 ratio rockers.
You will need to cut off the oil drip tabs off on the inside of the valve covers to make space for the larger rockers. Also, you should change valve springs to the LT4 springs, the LT1 springs will be really close to coil bind with the 1.6 ratio rockers.
Thread Starter
Instructor
Joined: Jan 2002
Posts: 104
Likes: 1
From: Gainesville FL
Re: Roller Rocker Opinions Please (STL94LT1)
Thanks for the info. I saw did a search on the internet and saw the Crane Gold 1.6's that you have. I found that you are right, Crane recommends that the Valve springs and retainers must be changed to allow for increased valve travel. I also have been searching on ebay and saw this: http://cgi.ebay.com/ebaymotors/ws/eB...tem=1872730342 These look Identical to the Crane Gold 1.6's but for a lot less. This guy occasionally sells this item with the buy it now for $169. Does anyone have any experience with these. I will probably assume the old saying "you get what you pay for"
Le Mans Master
Joined: Apr 2000
Posts: 5,713
Likes: 105
From: Manassas VA
Re: Roller Rocker Opinions Please (Lichen_1)
Those look like the proform rockers. I dont have any experience with any of them but it seems that most people are happy with the cranes, and comp. cam rockers.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Roller Rocker Opinions Please (Lichen_1)
For general info on cams and valve trains try the Comp Cam's web site: http://www.compcams.com/
Instructor
Joined: Apr 2002
Posts: 105
Likes: 0
From: Charlotte NC
Re: Roller Rocker Opinions Please (65Z01)
If I were buying rockers, I'd run Comp Pro-Magnum 1.6's. Theyre rebuildable, stronger than extruded aluminum, cheaper than the gold race's, and have a lower moment of inertia :). I'd run non-self aligning & guide plates, as self-aligning stuff is unstable and the tabs on the valve end will oftentimes limit your future component options (retainers/keepers if you need added installed height).
Thread Starter
Instructor
Joined: Jan 2002
Posts: 104
Likes: 1
From: Gainesville FL
Re: Roller Rocker Opinions Please (SkarodoM)
What to I gain using 1.6 and not a 1.5 besides a smother engine above 5k rpm? Is there any real RWHP on a stock lt1? Thanks for all the help.
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Thread Starter
Instructor
Joined: Jan 2002
Posts: 104
Likes: 1
From: Gainesville FL
Re: Roller Rocker Opinions Please (corvette0096)
Ok so here is the rundown:
1) Comp Pro Magnum Roller Rocker Arms 1.6's part number "1302-16C" from the following web page: http://www.compcams.com/information/.../ProMagnum.asp
2) Since I don't know what a guide plate is, would it come with the kit as well as retainers/keepers if not what kind or specific part numbers would I need?
3) Will I need new springs if so what kind/model number do I need.
Sorry for all the stupid questions, but I guess we all need to start somewhere and I want to do this right the first time.
:bb
1) Comp Pro Magnum Roller Rocker Arms 1.6's part number "1302-16C" from the following web page: http://www.compcams.com/information/.../ProMagnum.asp
2) Since I don't know what a guide plate is, would it come with the kit as well as retainers/keepers if not what kind or specific part numbers would I need?
3) Will I need new springs if so what kind/model number do I need.
Sorry for all the stupid questions, but I guess we all need to start somewhere and I want to do this right the first time.
:bb
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Re: Roller Rocker Opinions Please (Lichen_1)
heres the rub... the factory stamped steel rockers are junk.
they are supposed to be 1.5:1, but they vary from 1.45:1 to 1.55:1!!! usually below.
they also flex!
your engine will only run as well as the best rocker.
one member of the forum added RR's and picked up .2 of a second on the quarter mile! thats huge!
they are supposed to be 1.5:1, but they vary from 1.45:1 to 1.55:1!!! usually below.
they also flex!
your engine will only run as well as the best rocker.
one member of the forum added RR's and picked up .2 of a second on the quarter mile! thats huge!
Safety Car
Joined: Mar 2000
Posts: 3,581
Likes: 1
From: Springfield VA
Re: Roller Rocker Opinions Please (Lichen_1)
Here is another vote for the Comp Pro-Magnum 1.6's :yesnod:
There are two benefits of going to an aftermarket RR.
one of course is the quality control, balance, weight, etc. and the second is that on average the 1.6s will give you about a 6-6.5% increase in cam lift.
So yes you should see a real RWHP difference.
There are two benefits of going to an aftermarket RR.
one of course is the quality control, balance, weight, etc. and the second is that on average the 1.6s will give you about a 6-6.5% increase in cam lift.
So yes you should see a real RWHP difference.
Team Owner
Joined: Mar 2000
Posts: 83,383
Likes: 87
From: Boston, MA
I also use Comp Cam Pro Magnum 1.6 rockers.
The major benefit using a higher ratio rocker isn't so much the lift. The higher ratio rockers open your valves faster allowing air to enter the cylinder for a longer duration of time and also exit if you have them on the exhaust side also. They for all practical purposes add a couple of degrees of duration to your cam also.
The major benefit using a higher ratio rocker isn't so much the lift. The higher ratio rockers open your valves faster allowing air to enter the cylinder for a longer duration of time and also exit if you have them on the exhaust side also. They for all practical purposes add a couple of degrees of duration to your cam also.