roller tip rockers
Thread Starter
Le Mans Master
Joined: Jun 2008
Posts: 5,284
Likes: 235
From: Rockledge FL
roller tip rockers
OK I love to tinker. Turning a wrench is almost as satisfying as driving.
I have been reading about roller tip rockers. I found these at summit which include replacement pushrods. On my 72 454 would these 1.7 ratio roller tips be a worthwhile valve train upgrade on an otherwise stock motor.
http://store.summitracing.com/partde...3+&appfilter=1
I have been reading about roller tip rockers. I found these at summit which include replacement pushrods. On my 72 454 would these 1.7 ratio roller tips be a worthwhile valve train upgrade on an otherwise stock motor.
http://store.summitracing.com/partde...3+&appfilter=1
Drifting
Joined: Aug 2005
Posts: 1,682
Likes: 3
From: League City TX
You will never notice the difference in performance. Roller tips pretty much never roll.
If you want to make a difference you need to spend a little more and buy a real set of roller rockers.
The roller fulcrum is more important than the tip.
Even with full roller rockers you may not be able to feel much of a difference. Probably a 10hp improvement max.
If you want to make a difference you need to spend a little more and buy a real set of roller rockers.
The roller fulcrum is more important than the tip.
Even with full roller rockers you may not be able to feel much of a difference. Probably a 10hp improvement max.
Racer
Joined: Mar 2005
Posts: 393
Likes: 3
From: Dallas, TX
If you want to make power with a rocker change go with a numerically higher set, that is to say 1.8 for example instead of stock in a full roller variety, or better yet get some shaft mounted rockers like Jesel or T&D, they are pretty expensive but if you plan on making serious power they would definitely be a good thing to have. good luck with whatever you decide.
-alex
-alex
Le Mans Master
Joined: Oct 2007
Posts: 7,453
Likes: 976
From: RI, Now Franklin/Nashville TN
Comp Cams Roller 1.5 Rockers
15 years ago I put a set of Comp Cams roller 1.5 rockers on my basically stock 78 L-82 motor for a number of reasons. First, roller rockers do provide much better valve timing than the OEM stamped steel rockers which are not made with much precision. Roller rockers are much stronger than the original OEM rockers. Less friction and more precise production methods resulted in two articles I read at the time of a bone fide 20 HP increase to a mid 80's vette 350 with zero changes other than the 1.5 rockers, not 1.6, to the motor on a dyno according to the corvette magazine article. This gain was also verified in a Carcraft magazine article with the roller rocker modification to a V6 Pontiac Grandprix (2000). Another benefit is that the L-82 which is known for its rough idle smoothed out considerably with the 1.5 roller rockers. There is a definite plus to the roller rockers!
Last edited by jb78L-82; Jul 25, 2008 at 07:14 AM.
Thread Starter
Le Mans Master
Joined: Jun 2008
Posts: 5,284
Likes: 235
From: Rockledge FL
yeah i have been searching but i cant find anything really specific to the 1.7 ratio that summit suggests when you go through all their menus.
if i read correctly stock is 1.5 right?
i have found that even if the roller tips dont add hp they reduce friction in the valvetrain and smooth idle up, which cant be bad i think
if i read correctly stock is 1.5 right?
i have found that even if the roller tips dont add hp they reduce friction in the valvetrain and smooth idle up, which cant be bad i think
Le Mans Master
Joined: Jan 2006
Posts: 6,506
Likes: 139
From: Butler Pa
yeah i have been searching but i cant find anything really specific to the 1.7 ratio that summit suggests when you go through all their menus.
if i read correctly stock is 1.5 right?
i have found that even if the roller tips dont add hp they reduce friction in the valvetrain and smooth idle up, which cant be bad i think
if i read correctly stock is 1.5 right?
i have found that even if the roller tips dont add hp they reduce friction in the valvetrain and smooth idle up, which cant be bad i think
How could they smooth the idle?
Le Mans Master
Joined: Oct 2007
Posts: 7,453
Likes: 976
From: RI, Now Franklin/Nashville TN
1.5 rocker is stock on SBC. Please read my comments above which are from technical articles written on this subject. Roller rockers reduce friction and allow much more accurate valve timing, thus smoother idle.
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Drifting
Joined: Aug 2005
Posts: 1,682
Likes: 3
From: League City TX
They are designed to sell magazines & promote advertisers products.
Take anything you read in a magazine with a grain of salt.
Notice that when GM decided to use roller rockers, they had a roller fulcrum & a regular tip at the valve.
Le Mans Master
Joined: Oct 2007
Posts: 7,453
Likes: 976
From: RI, Now Franklin/Nashville TN
Technical articles? Come on now, they were magazine articles.
They are designed to sell magazines & promote advertisers products.
Take anything you read in a magazine with a grain of salt.
Notice that when GM decided to use roller rockers, they had a roller fulcrum & a regular tip at the valve.
They are designed to sell magazines & promote advertisers products.
Take anything you read in a magazine with a grain of salt.
Notice that when GM decided to use roller rockers, they had a roller fulcrum & a regular tip at the valve.
Last edited by jb78L-82; Jul 25, 2008 at 10:39 AM.
Pro
Joined: Jul 2008
Posts: 699
Likes: 3
From: Millersville, MD
I installed 1.52 roller rockers when I did my top-end rebuild. I installed them taking into consideration heat, friction and quality knowing that there will be minimal performance gain if any at all. There definitley is a benefit to installing them over OEM but for performance gain, probably not.
Le Mans Master
Joined: Oct 2007
Posts: 7,453
Likes: 976
From: RI, Now Franklin/Nashville TN
I installed 1.52 roller rockers when I did my top-end rebuild. I installed them taking into consideration heat, friction and quality knowing that there will be minimal performance gain if any at all. There definitley is a benefit to installing them over OEM but for performance gain, probably not.
Last edited by jb78L-82; Jul 25, 2008 at 11:14 AM.
Le Mans Master
Joined: Oct 2000
Posts: 7,831
Likes: 5
From: Austin TX
The stock big block rockers are 1.70.
(I think the original spec was 1.72 but
that seemed to get lost along the way).
Anyway, the Comp Cams Magnums are the full 1.72.
Stock rockers are a little short of the 1.70.
So, say the stockers are 1.67 and your lobe is .300:
stock lift would be .501
Comp lift would be .516
That's not bad... And the Comps are more accurate
while the stockers may range a bit.
As mentioned above the roller tips probably just slide on the valve tip.
(I think the original spec was 1.72 but
that seemed to get lost along the way).
Anyway, the Comp Cams Magnums are the full 1.72.
Stock rockers are a little short of the 1.70.
So, say the stockers are 1.67 and your lobe is .300:
stock lift would be .501
Comp lift would be .516
That's not bad... And the Comps are more accurate
while the stockers may range a bit.
As mentioned above the roller tips probably just slide on the valve tip.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
If you use higher ratio rockers, you just need to make sure that the valves aren't going to make contact with the pistons [as the increased ratio rockers will cause deeper valve movement].
Burning Brakes
Joined: Aug 2006
Posts: 1,155
Likes: 0
From: San Diego California
You will never notice the difference in performance. Roller tips pretty much never roll.
If you want to make a difference you need to spend a little more and buy a real set of roller rockers.
The roller fulcrum is more important than the tip.
Even with full roller rockers you may not be able to feel much of a difference. Probably a 10hp improvement max.
If you want to make a difference you need to spend a little more and buy a real set of roller rockers.
The roller fulcrum is more important than the tip.
Even with full roller rockers you may not be able to feel much of a difference. Probably a 10hp improvement max.
This is consistent with what I've read. Nevertheless, when I rebuilt my engine to a 355,, I installed the Summit 1.5 roller tip rockers- good price and fit under stock valve covers.
Drifting
Joined: Aug 2004
Posts: 1,883
Likes: 124
From: Lubbock TX
I'm with Driveshaft on this one.
If you're going to spend the money, get some Harland Sharp aluminum full rollers. They're some of the least expensive and are great quality.
I've seen spintron tests where they showed high speed camera shots of a roller tip rocker - the wheels don't turn, they tend to slide across the valve tip just like a stocker. They do have a smaller contact area, though, and tend to rock the valve in the guide less.
If you're going to spend the money, get some Harland Sharp aluminum full rollers. They're some of the least expensive and are great quality.
I've seen spintron tests where they showed high speed camera shots of a roller tip rocker - the wheels don't turn, they tend to slide across the valve tip just like a stocker. They do have a smaller contact area, though, and tend to rock the valve in the guide less.
Le Mans Master
Joined: Oct 2007
Posts: 7,453
Likes: 976
From: RI, Now Franklin/Nashville TN
I agree for a top end or full blown engine rebuild the more advanced Roller Rockers are probably a better choice. However, there still remains three advantages to the "standard" Roller Tip Rockers: 1. More precise valve actuataion/timing. 2. Added strength over stock OEM rockers. 3. Less friction, regardless of whether the roller ball turns or slides over the valve, versus the OEM rocker.
For a minor modification on basically stock motors, the Roller tip rockers are an economic upgrade, IMHO.
For a minor modification on basically stock motors, the Roller tip rockers are an economic upgrade, IMHO.
Thread Starter
Le Mans Master
Joined: Jun 2008
Posts: 5,284
Likes: 235
From: Rockledge FL
so,
it sounds like it might be a worthwhile weekend project.
maybe do that along with swapping the cast iron intake with a 69 427 aluminum one as well.
final question though,
do the comp cams roller tip rockers require guideplates to be installed.
if they do then its probably more work than i want to put into it.
it sounds like it might be a worthwhile weekend project.
maybe do that along with swapping the cast iron intake with a 69 427 aluminum one as well.
final question though,
do the comp cams roller tip rockers require guideplates to be installed.
if they do then its probably more work than i want to put into it.