Roller tip rockers - Team Camaro Tech
Engine General Engine Discussion.

 5Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 18 (permalink) Old Jan 20th, 20, 07:54 PM Thread Starter
Tech Team
danny
 
Join Date: Jun 2011
Location: highpoint, nc
Posts: 32
Roller tip rockers

Thinking about putting new rockers and rods in and want to go with roller tip but the motor is all stock with double hump heads. Can I replace stock rockers with the same dimension self aligning rollers ? And no guide plate
camarolover#1 is offline  
Sponsored Links
Advertisement
 
post #2 of 18 (permalink) Old Jan 20th, 20, 08:26 PM
Senior Tech
Lonnie
 
Lonnie P's Avatar
 
Join Date: Sep 2008
Location: Pittsburgh, pa
Posts: 610
Re: Roller tip rockers

Self-aligning rockers are meant for later model engines... approx 89 & up.

If you have double hump heads with screw in studs, you should use guide plates.

With pressed in studs, there are slots in the heads that align the rockers. You would need a standard type roller rocker.
Lonnie P is offline  
post #3 of 18 (permalink) Old Jan 20th, 20, 10:19 PM
Gold Lifetime Member
Chris
 
Join Date: Oct 2013
Location: Texas
Posts: 1,061
Re: Roller tip rockers

I tried some roller tips on my double hump heads and they did not work out well so I removed them. If you are going to replace the push rods at the same time you will be able to get spot on matching the roller tip with the top of the valve so that will remove one possible geometry issue. As for guide plates, my heads don't have them, but I'm just running stock OEM rockers. I'd say either stay stock or go full boat with full roller rockers, but then full rollers probably won't fit under your stock valve covers if that's what you want to use. You'll probably need taller valve covers to clear the larger roller rockers, but I've not made this change so I'm not sure about that and perhaps someone here can clarify that point.

'69 Z/28, Lemans Blue/White Stripes, DZ302, Tremec Magnum, 4.10, Procar Elite Seats,
Custom Upholstery, Dynatech headers, 17" VWW V45's, 235/45, 275/40, C5 Front Brakes
ctcz28 is offline  
 
post #4 of 18 (permalink) Old Jan 21st, 20, 06:57 AM
Moderator
Bill
 
Join Date: Aug 1998
Location: Waldorf Md. USA
Posts: 3,306
Re: Roller tip rockers

Danny,
You should be able to replace them with a roller tip rocker like the Comp Cams 1412-16 but I really don't think you are going to gain anything. Why are you replacing the rockers ?
rp930 likes this.

Bill Koustenis
Owner
Advanced Automotive Machine
Waldorf Md
1971 Chevelle "Heavy Chevy" original owner


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
BillK is offline  
post #5 of 18 (permalink) Old Jan 21st, 20, 09:25 AM
Senior Tech
Dave
 
Join Date: Dec 2005
Location: Tampa, Florida
Posts: 4,726
Re: Roller tip rockers

Like bill stated just a roller tip gains you nothing as ninety percent of the friction is in the ball that the rocker uses to rotate. All of the issues of a roller rocker not fitting under the stock valve cover is due to the poly-lock adjuster hitting the valve cover preventing it seating.

Believe it or not all of the major cam companies that sell roller rockers also sell at additional cost another set of sixteen short poly-lock nuts just to clear a stock valve cover (it's not like they are unaware of the problem). The ones they do sell cause interference issues, and they are too short to run a stud girdle which baits the question as to why they include them with their roller rockers except to make you spend more money. To buy the shorter poly locks you use the letter S for Short, Or LP for low profile after the "Standard" part number that you do not need.

Buying a set of roller rockers will not make any horsepower in a stock (1.5:1) ratio, but they will free up 17 to 23 horsepower associated with friction (called parasitic drag for some reason). The variation in friction depends upon the spring pressure on your heads. Lower spring pressure means less friction at the trunion.

If you have press in rocker arm studs you need to remove the heads and have them machined to use a screw in stud or at least pin the press in stud to keep it from pulling out under higher RPMs. Stock parts were made to keep production costs down, not to make horsepower or to be reliable when raced.

Big Dave
HawkX66 and flat tire like this.
Larger Dave is offline  
post #6 of 18 (permalink) Old Jan 21st, 20, 08:20 PM
Senior Tech
Lonnie
 
Lonnie P's Avatar
 
Join Date: Sep 2008
Location: Pittsburgh, pa
Posts: 610
Re: Roller tip rockers

Actually it has been documented that the ratio of stock rocker arms varies slightly & is typically less than 1.5:1 (more like 1.4 to 1.47), so will likely pick up some power here as well.
Lonnie P is offline  
post #7 of 18 (permalink) Old Jan 21st, 20, 08:51 PM
Gold Lifetime Member
Gary
 
69Z28's Avatar
 
Join Date: Oct 2000
Location: Delaware
Posts: 3,487
Re: Roller tip rockers

Quote:
Originally Posted by Lonnie P View Post
Actually it has been documented that the ratio of stock rocker arms varies slightly & is typically less than 1.5:1 (more like 1.4 to 1.47), so will likely pick up some power here as well.

I heard as low as 1.37 on the OEM rockers. When I had my 186 heads redone I had all the pressed in studs pulled, and went with NON SHOULDER screw-in type, and use the above mention 1.5 roller tip rockers with no issues. I've run the 30/30 cam and the 140 cam. Works for me.

06A 1969 Camaro Z28 711 69 B Black Stripes Console w/tach and gauges
69Z28 is offline  
post #8 of 18 (permalink) Old Jan 27th, 20, 05:26 PM
Team Member
Brian
 
BH69Z/28's Avatar
 
Join Date: Dec 2017
Location: New Hampshire
Posts: 49
Garage
Re: Roller tip rockers

Quote:
Originally Posted by 69Z28 View Post
I heard as low as 1.37 on the OEM rockers. When I had my 186 heads redone I had all the pressed in studs pulled, and went with NON SHOULDER screw-in type, and use the above mention 1.5 roller tip rockers with no issues. I've run the 30/30 cam and the 140 cam. Works for me.
Gary, could you tell me what method you used to adjust the valves using the roller tip rockers and the 30/30 cam? Thanks

Brian
BH69Z/28 is offline  
post #9 of 18 (permalink) Old Jan 27th, 20, 06:35 PM
Gold Lifetime Member
Gary
 
69Z28's Avatar
 
Join Date: Oct 2000
Location: Delaware
Posts: 3,487
Re: Roller tip rockers

Quote:
Originally Posted by BH69Z/28 View Post
Gary, could you tell me what method you used to adjust the valves using the roller tip rockers and the 30/30 cam? Thanks

I used John Hinckley's method, but used .030 clearance since the rockers are 1.50.1 Something I noticed doing it this way is the rockers aren't as clackity-clackity sounding and not as noisy as with the 1.37 OEM rockers. AAAAANNNNNDDDD...I haven't a need to re-adjust as often. My engine runs smooth as glass at all RPM's. I've hit 7200, but don't usually go that high for long periods. 6500 is my limit and it sings really high notes.

CRG Research Report - 302ci Engine OEM Valve Adjustment
HawkX66 likes this.

06A 1969 Camaro Z28 711 69 B Black Stripes Console w/tach and gauges
69Z28 is offline  
post #10 of 18 (permalink) Old Jan 27th, 20, 06:41 PM
Gold Lifetime Member
Scott
 
scblucam's Avatar
 
Join Date: May 2005
Location: Houston, TX
Posts: 2,514
Garage
Re: Roller tip rockers

Screw in Studs, Guide Plates, Hardened Push Rods. And it is very possible you may need different length push rods with the change so get a pushrod length checker. Or just slap them on there and hope it works.

68 302 M20 - 85 IROC Z
The older I get the faster I was.
scblucam is offline  
post #11 of 18 (permalink) Old Jan 28th, 20, 07:24 PM
Team Member
Brian
 
BH69Z/28's Avatar
 
Join Date: Dec 2017
Location: New Hampshire
Posts: 49
Garage
Re: Roller tip rockers

Quote:
Originally Posted by 69Z28 View Post
I used John Hinckley's method, but used .030 clearance since the rockers are 1.50.1 Something I noticed doing it this way is the rockers aren't as clackity-clackity sounding and not as noisy as with the 1.37 OEM rockers. AAAAANNNNNDDDD...I haven't a need to re-adjust as often. My engine runs smooth as glass at all RPM's. I've hit 7200, but don't usually go that high for long periods. 6500 is my limit and it sings really high notes.

CRG Research Report - 302ci Engine OEM Valve Adjustment
Thanks, I use the same method but have stamped steel rockers and mine won’t idle well and has about 7” of manifold vacuum when I set the lash at .026” cold. It idles better and has about 10” of vacuum when I set them at .030” cold. My rockers are from Howard’s Cams, so I wonder they’re closer to 1.50:1 than 1:37:1.
69Z28 likes this.

Brian
BH69Z/28 is offline  
post #12 of 18 (permalink) Old Jan 28th, 20, 09:33 PM
Gold Lifetime Member
Gary
 
69Z28's Avatar
 
Join Date: Oct 2000
Location: Delaware
Posts: 3,487
Re: Roller tip rockers

Quote:
Originally Posted by BH69Z/28 View Post
Thanks, I use the same method but have stamped steel rockers and mine won’t idle well and has about 7” of manifold vacuum when I set the lash at .026” cold. It idles better and has about 10” of vacuum when I set them at .030” cold. My rockers are from Howard’s Cams, so I wonder they’re closer to 1.50:1 than 1:37:1.

I couldn't say about the Howards rockers, but I bet they are 1.5's since aftermarket. I don't remember what vacuum I ended up with, I'm thinking it was around the 10" area as well. My brakes work well when I do a panic stop from time to time. Initially I did the settings like you did. I WAS confused since it doesn't say specifically in JohnZ's write up with 1.5 or the OEM rockers where used. I had to KEEP asking this one question until I said 'F' it, and went to straight .030 when the specs say using 1.5. Staring me right in the face the whole time...LOL, and that was all I needed.



I just rebuilt the short block recently and still up in the air on what head gaskets I should use. Seems there is no easy answer for this or so it seems. Is your engine a stock build or? What head gaskets are you using? I had the heads skimmed/shaved, but not the block deck and pistons are down .021 from the deck. Not sure if I want to use a shim style or. Thoughts?

06A 1969 Camaro Z28 711 69 B Black Stripes Console w/tach and gauges
69Z28 is offline  
post #13 of 18 (permalink) Old Jan 29th, 20, 07:41 AM
Senior Tech
Rick
 
Join Date: Sep 2012
Location: Denver
Posts: 567
Re: Roller tip rockers

Quote:
Originally Posted by BH69Z/28 View Post
Thanks, I use the same method but have stamped steel rockers and mine won’t idle well and has about 7” of manifold vacuum when I set the lash at .026” cold. It idles better and has about 10” of vacuum when I set them at .030” cold. My rockers are from Howard’s Cams, so I wonder they’re closer to 1.50:1 than 1:37:1.
If .004” made 3” difference in vacuum, something is wrong.

I would use this method. https://www.hotrod.com/articles/ccrp-0702-camshaft/

69 COPO clone, 461" BBC 11.25:1 Compression
840 Rec Heads (2.25/1.88) AED 850 HO carb
Orig Exhaust Manifolds
Straub (Clay Smith) cam, 288/300 .600/.569 109.
TH400, 3500 stall, 4.11 12 bolt posi
rp930 is offline  
post #14 of 18 (permalink) Old Jan 29th, 20, 09:03 AM
Senior Tech
Dave
 
Join Date: Dec 2005
Location: Tampa, Florida
Posts: 4,726
Re: Roller tip rockers

Quote:
If .004” made 3” difference in vacuum, something is wrong.
My guess is valve springs that are too weak for a solid cam. I suspect the valves are bouncing off the seats on closing.

Tightening the lash affects duration numbers with the affect upon torque by decreasing it slightly, and your horsepower will improve slightly but it will be achieved at a higher rpm.

https://www.hotrod.com/articles/ccrp...ng-valve-lash/

Big Dave
Larger Dave is offline  
post #15 of 18 (permalink) Old Jan 29th, 20, 10:57 AM
Team Member
Brian
 
BH69Z/28's Avatar
 
Join Date: Dec 2017
Location: New Hampshire
Posts: 49
Garage
Re: Roller tip rockers

Quote:
Originally Posted by 69Z28 View Post
I just rebuilt the short block recently and still up in the air on what head gaskets I should use. Seems there is no easy answer for this or so it seems. Is your engine a stock build or? What head gaskets are you using? I had the heads skimmed/shaved, but not the block deck and pistons are down .021 from the deck. Not sure if I want to use a shim style or. Thoughts?
Sorry but I can't help with this one, the engine was already built and came with the car when i bought it, and I'm not sure on some of these details as the guy threw away the receipts. I did get in touch with the shop who built it, but they weren't sure on some details either but remembered they had built it as a stock 302.

Quote:
Originally Posted by rp930 View Post
If .004” made 3” difference in vacuum, something is wrong.

I would use this method. https://www.hotrod.com/articles/ccrp-0702-camshaft/
I was thinking about that, but the article posted on the CRG site says that using the EOIC method doesn't have the lifters on the base circle (or something to that effect), so I used that method. Do you know if the EOIC method definitely works on the 30-30 cam. One other thing is that I'm not exactly sure which brand of 30-30 cam is in it, could be Melling, Crane, or Comp cam 30-30 version.

Quote:
Originally Posted by Larger Dave View Post
My guess is valve springs that are too weak for a solid cam. I suspect the valves are bouncing off the seats on closing.

Tightening the lash affects duration numbers with the affect upon torque by decreasing it slightly, and your horsepower will improve slightly but it will be achieved at a higher rpm.

https://www.hotrod.com/articles/ccrp...ng-valve-lash/

Big Dave
Thank you, please see my question above too.

Brian
BH69Z/28 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome