1.6 rocker ?
Thread Starter
Drifting
Joined: Jan 2003
Posts: 1,894
Likes: 3
From: Reading PA.
1.6 rocker ?
Would I be able to change my stock rocker arms to 1.6 rollers without changing valve springs ? The motor is a stock 90 L 98. Do I have to worry about pulling a rocker stud out of the head or breaking a pushrod with this swap? I just want to try and get a little more out of it before going to the good motor. THANKS FOR THE REPLIES Pipe
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
The stock rocker arm studs are 3/8" screw-in so no danger of pulling out.
Our stock #113 heads have factory non-hardened and non-functional guide plates with self aligning rockers.
So I installed non self aligning 1.6:1 ProMagnum RRs with hardened guide plates & pushrods along with 7/16" studs. This path is about the same total cost as going with self aligning RRs.
Also you should install new valve springs and forged keepers. I used the Comp Cams #981 springs shimmed to give about 120lb of seat force.
Since the springs will be out it would be a good time to install new valve seals too. On reassembly, toss the stock tin oil shedders from atop the valve springs to lighten the valve train a little.
You can expect to gain around 15-20chp this mod with a stock cam.
Our stock #113 heads have factory non-hardened and non-functional guide plates with self aligning rockers.
So I installed non self aligning 1.6:1 ProMagnum RRs with hardened guide plates & pushrods along with 7/16" studs. This path is about the same total cost as going with self aligning RRs.
Also you should install new valve springs and forged keepers. I used the Comp Cams #981 springs shimmed to give about 120lb of seat force.
Since the springs will be out it would be a good time to install new valve seals too. On reassembly, toss the stock tin oil shedders from atop the valve springs to lighten the valve train a little.
You can expect to gain around 15-20chp this mod with a stock cam.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
And you will need to grind down the drip tabs inside the valve covers as well as narrow the bolt towers to clear the Pro Magnum RRs.
It isn't "necessary" to change all those items but I feel it makes sense once you go in there.
It isn't "necessary" to change all those items but I feel it makes sense once you go in there.
Pro
Joined: Jan 2004
Posts: 707
Likes: 0
From: Syracuse Utah
Just changing the rockers to rollers will not cause any problems. The 1.6 rockers don't really add much lift on a stock system (read that stock cam) so the springs should be fine. However, it does make sense to upgrade the springs at the same time.
Instructor
Joined: Apr 2004
Posts: 100
Likes: 0
From: JOPLIN MO
Originally Posted by Hotred94
Just changing the rockers to rollers will not cause any problems. The 1.6 rockers don't really add much lift on a stock system (read that stock cam) so the springs should be fine. However, it does make sense to upgrade the springs at the same time.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
My stock '88 valve springs only provide 86 lbs at the seat, which may be fine for a 4,800rpm L98, but I now wind to 5,700rpm so I went with Comp Cams springs at 110 lbs and lightened the valve train too.
Of course changing springs complicates the issue but doesn't bump to cost excessively compared with $260 RRs. Now adding Ti retainers at $140 a set will give costing a nice bump.
Of course changing springs complicates the issue but doesn't bump to cost excessively compared with $260 RRs. Now adding Ti retainers at $140 a set will give costing a nice bump.
Last edited by 65Z01; Jun 23, 2005 at 11:25 PM.
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