roller rocker arms vs. non roller rocker arms(stock)
Thread Starter
Member
iTrader: (1)
Joined: Mar 2002
Posts: 216
Likes: 1
From: Southeastern Wisconsin
Transmission: Automatic!
roller rocker arms vs. non roller rocker arms(stock)
Im wondering why the rocker arms are different for roller cams compared to the non roller cam cars from what Ive seen...
Case in point, the rocker arms from my 87' LG4 non roller motor have edges that keep the valve stem in the middle during operation.
The rocker arms from a 87' LB9 I used the TPI and roller parts from have no such edges for the valve stem. Why is this? This is probably a simple question, but to me the ones with edges make more sense to keep the stem in the middle...but I assume the roller ones are not there for a purpose.
Last question, would it hurt to use the non roller rocker arms on a roller cam car? On my TPI/roller cam-ed LG4(LB9 parts on the LG4 block/heads) cylinder #1's exhaust valve the roller tip rocker was falling off, so I just put one of the Montes non roller rocker tips on, and it works just fine now. Im curious if this will cause a problem, and if so, what it would be.
Which rocker arm should I use with the LG4 heads, roller cam and corresponding pushrods, and roller cam parts? TIA.
Case in point, the rocker arms from my 87' LG4 non roller motor have edges that keep the valve stem in the middle during operation.
The rocker arms from a 87' LB9 I used the TPI and roller parts from have no such edges for the valve stem. Why is this? This is probably a simple question, but to me the ones with edges make more sense to keep the stem in the middle...but I assume the roller ones are not there for a purpose.
Last question, would it hurt to use the non roller rocker arms on a roller cam car? On my TPI/roller cam-ed LG4(LB9 parts on the LG4 block/heads) cylinder #1's exhaust valve the roller tip rocker was falling off, so I just put one of the Montes non roller rocker tips on, and it works just fine now. Im curious if this will cause a problem, and if so, what it would be.
Which rocker arm should I use with the LG4 heads, roller cam and corresponding pushrods, and roller cam parts? TIA.
Member
Joined: Aug 2002
Posts: 223
Likes: 0
From: Canada
Car: 87 Firebird
Engine: 350, 416's, 230/230 cam, torkerII, q-jet
Transmission: T5
originally posted by rb83l69
There are 3 possible systems to giude the rocker arms. One, AND ONLY ONE, must be in effect at any time.
The narrow slots that fit tight to the push rods are the original design, used on these motors from 1955 to 1986.
Guide plates can be added to any heads; but if the heads have the narrow slots, the slots MUST be enlarged. Odds are somewhere between slim and none that the slots in the heads would just happen to exactly line up with the slots in the guide plates.
Or, they can use the 87-up "self-aligning" rockers with the "lips". If these rockers are used, there MUST NOT be any guide plates, and the heads MUST have the large holes. The new-style rockers can therefore be used on early heads whose holes have been enlarged, as well as on later heads that already come that way from the factory.
If your heads have the narrow slots, then you MUST NOT use either self-aligning rockers or guide plates, without further machine work.
It's really quite simple, as you can see. What would you like to know?
The narrow slots that fit tight to the push rods are the original design, used on these motors from 1955 to 1986.
Guide plates can be added to any heads; but if the heads have the narrow slots, the slots MUST be enlarged. Odds are somewhere between slim and none that the slots in the heads would just happen to exactly line up with the slots in the guide plates.
Or, they can use the 87-up "self-aligning" rockers with the "lips". If these rockers are used, there MUST NOT be any guide plates, and the heads MUST have the large holes. The new-style rockers can therefore be used on early heads whose holes have been enlarged, as well as on later heads that already come that way from the factory.
If your heads have the narrow slots, then you MUST NOT use either self-aligning rockers or guide plates, without further machine work.
It's really quite simple, as you can see. What would you like to know?
Thread Starter
Member
iTrader: (1)
Joined: Mar 2002
Posts: 216
Likes: 1
From: Southeastern Wisconsin
Transmission: Automatic!
Thanks for the reply with the info.
Now what exactly are the guide plates?
The guides that go around the lifters that come on roller cam cars stock?
Trying to picture what I have, the heads I have are from a 87' LG4, I think the pushrod holes are the same on the LB9 motor I took apart. So if Im using those guide plates around the lifters I should not use the rocker arms that have the *lips*, and vice versa.
If I use both, what would wear or cause the problem? TIA.
Now what exactly are the guide plates?
The guides that go around the lifters that come on roller cam cars stock?
Trying to picture what I have, the heads I have are from a 87' LG4, I think the pushrod holes are the same on the LB9 motor I took apart. So if Im using those guide plates around the lifters I should not use the rocker arms that have the *lips*, and vice versa.
If I use both, what would wear or cause the problem? TIA.
Moderator
Joined: Jan 2000
Posts: 19,664
Likes: 313
Guide plates are typically aftermarket parts that are bolted to the head by the rocker studs (requiring screwed rocker studs). The factory didn't use them in either configuration.
Can you attach a photo fo the push rod holes in the head for the engine in question?
Can you attach a photo fo the push rod holes in the head for the engine in question?
Thread Starter
Member
iTrader: (1)
Joined: Mar 2002
Posts: 216
Likes: 1
From: Southeastern Wisconsin
Transmission: Automatic!
Ill take a picture pretty soon, might be a short while before I get the film back though...just started a new roll and I dont go taking pics of everything in sight 
, well most times I dont.
I understand what the guide plates are now, but what is the reason the rocker arms would be slightly different on the flat tappet LG4 to the roller cam LB9? Just the part that goes to the valve is different with the *lips*.
It just seems the arms with the *lips* make more sense to keep it all aligned, but Im not claiming to be an engine expert either
.
, well most times I dont.I understand what the guide plates are now, but what is the reason the rocker arms would be slightly different on the flat tappet LG4 to the roller cam LB9? Just the part that goes to the valve is different with the *lips*.
It just seems the arms with the *lips* make more sense to keep it all aligned, but Im not claiming to be an engine expert either
. Member
Joined: Aug 2002
Posts: 223
Likes: 0
From: Canada
Car: 87 Firebird
Engine: 350, 416's, 230/230 cam, torkerII, q-jet
Transmission: T5
It does not matter whether it is a roller cam or not.
Like Vader said the deciding factor is usually the holes in the heads.
If the pushrod holes are slotted looking and just barely wide enough for the pushrod then you shoud use non-self aligning rockers (no "lips" or "****").
If the pushrod holes are big and sloppy then you shoud use self aligning rockers (with "lips" or "****").
Most of this has been said but I couldn't help making a post with the words lips, ****, and big sloppy holes.
Like Vader said the deciding factor is usually the holes in the heads.
If the pushrod holes are slotted looking and just barely wide enough for the pushrod then you shoud use non-self aligning rockers (no "lips" or "****").
If the pushrod holes are big and sloppy then you shoud use self aligning rockers (with "lips" or "****").
Most of this has been said but I couldn't help making a post with the words lips, ****, and big sloppy holes.
Thread Starter
Member
iTrader: (1)
Joined: Mar 2002
Posts: 216
Likes: 1
From: Southeastern Wisconsin
Transmission: Automatic!
I swapped all the rocker arms over to the ones with the ****** . I had the holes, not the slots...another arm on the passenger side was starting to come off as well....good thing I caught it! Thanks for the help.
. I had the holes, not the slots...another arm on the passenger side was starting to come off as well....good thing I caught it! Thanks for the help. 
Thread
Thread Starter
Forum
Replies
Last Post
ambainb
Camaros for Sale
11
Apr 25, 2016 09:21 PM
Dialed_In
Firebirds for Sale
2
Aug 20, 2015 01:45 PM
IrocZ'85
Engine/Drivetrain/Suspension Parts for Sale
0
Aug 17, 2015 06:24 PM
