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Re: How do roller rockers improve performance?
[Re: 4speeds4me]
#1631071
06/10/14 03:22 AM
06/10/14 03:22 AM
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Joined: Aug 2003
Posts: 12,589
Sacramento, CA
cal_gecko
OP
I Live Here
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OP
I Live Here
Joined: Aug 2003
Posts: 12,589
Sacramento, CA
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Quote:
I remember reading an article years ago that stated that roller rockers were one of the BIGGEST money wasters in the average street engine...$400 (since that's the dollar figure floating around in this thread) will give you noticeable gains in the heads, but you'll likely never see it in the rockers.
They'll sure look purty, though! 
so are you saying I'd be better off spending $400 in head work than changing out the rockers?
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Re: How do roller rockers improve performance?
[Re: cal_gecko]
#1631072
06/10/14 03:45 AM
06/10/14 03:45 AM
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Joined: May 2008
Posts: 5,399
Aurora, Colorado
451Mopar
master
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master
Joined: May 2008
Posts: 5,399
Aurora, Colorado
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Adjustable rockers allow you to adjust lifter pre-load with a hydraulic cam, or lash on a solid cam.
Higher ratios rocker arms allow more lift at the valve which makes the cam seem a bit larger.
The roller tip rockers are supposed to eliminate the rubbing action across the tip of the valve stem. This feature is more important when using higher lift cams with higher valve spring pressures.
Full roller rockers with rollers on the rocker shaft are supposed to help reduce friction.
The stock rockers do a good job, but the actual rocker ratio is less than 1.5:1, and with higher valve spring pressures, the pushrod can break through the rocker arm. They are also non-adjustable.
On a small block, if you goto a higher rocker ratio like 1.6:1, you should enlarge the pushrod holes in the cylinder heads, because the higher ratio comes from moving the pushrod closer to the center of the rocker arm.
You will likely need new custom length pushrods too.
As for the quality of rocker arm, alot depends on your valve spring pressures. I have a friend who is running those rocker arms on a really mild (near stock) engine and he says they are fine?
I bought a set of the identical looking "CAT" rocker arms for my 440, and they had issues with the roller tips wearing. I think the stainless bodies of the rockers are OK. They had good geometry, but really to be useful they would have to be rebuilt with hardened roller tips and pins, and the adjusters replaced with better quality ones. Anyhow, I learned my lesson and I'm running Harlan Sharpe rockers on my 440 now.
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Re: How do roller rockers improve performance?
[Re: cal_gecko]
#1631073
06/10/14 04:12 AM
06/10/14 04:12 AM
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Joined: Jan 2003
Posts: 8,089
Sorrento, BC, Canada
4speeds4me
master
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master
Joined: Jan 2003
Posts: 8,089
Sorrento, BC, Canada
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That's what I'm saying. I know lots of guys like them, and at times, so do I. But under .550" lift, that money can be better spent getting air in and out...and as far as side loading of the valve or scrubbing the tip is concerned, how many miles do the average one of us put on these cars? In 10 years we MIGHT have worn things enough to cause an issue.
All that said, if you're in a position where you NEED to buy rockers (change to solid cam, preload issues, etc) then buying a quality set of adjustables/pushrods isn't a bad idea, and roller tipped are going to be marginally more expensive...
2 Demons...no, not my kids!
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Re: How do roller rockers improve performance?
[Re: 4speeds4me]
#1631074
06/10/14 05:18 AM
06/10/14 05:18 AM
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Joined: Aug 2003
Posts: 12,589
Sacramento, CA
cal_gecko
OP
I Live Here
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OP
I Live Here
Joined: Aug 2003
Posts: 12,589
Sacramento, CA
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Quote:
That's what I'm saying. I know lots of guys like them, and at times, so do I. But under .550" lift, that money can be better spent getting air in and out...and as far as side loading of the valve or scrubbing the tip is concerned, how many miles do the average one of us put on these cars? In 10 years we MIGHT have worn things enough to cause an issue..
I've put 3300 miles on the Dart since the beginning of December 
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Re: How do roller rockers improve performance?
[Re: cal_gecko]
#1631075
06/10/14 07:56 AM
06/10/14 07:56 AM
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Joined: Jan 2003
Posts: 20,166
Park Forest, IL
slantzilla
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 20,166
Park Forest, IL
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I have a set of 1.6 ratio rollers for my Slant. I normally run stock rockers which are in the neighborhood of 1.5. I tried them back to back to back against each other the same day at the track. There was 0 difference. This was with a good ported head and a .560" lift cam.
"Everybody funny, now you funny too."
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Re: How do roller rockers improve performance?
[Re: slantzilla]
#1631077
06/10/14 08:18 AM
06/10/14 08:18 AM
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Joined: Jan 2003
Posts: 10,702
North Dakota
6PakBee
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 10,702
North Dakota
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I like stock rockers because of their simplicity, cost, and that they are part of a total engineered package. The only drawback is that the ratio is all over the map. What I did years ago was get a bunch of rockers and check the lift on each one. Then I split them into intake and exhaust sets that had approximately the same ratio. Worked well so far. As to the technique, it isn't mine, Racer Brown was promoting this 35 years ago.
"We live in a time when intelligent people are being silenced so that stupid people won't be offended".
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Re: How do roller rockers improve performance?
[Re: Sinitro]
#1631078
06/10/14 11:27 AM
06/10/14 11:27 AM
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Joined: Jan 2003
Posts: 74,974
U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 74,974
U.S.S.A.
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Quote:
Quote:
Those rockers would improve performance because of the ratio change from what your current rockers are , CLAIMED 1.5 , to a claimed 1.6 , increase lift and duration without a cam change.
There is no real performance gain by just switching to a roller tipped rocker.
The quality of those rockers ???
Rockers arms are one place to not buy cheap Chinese junk . Ask those that bought off shore big block rockers because they were CHEAP , only to have them cause a dropped valve ...
Are U aware the PRW rockers are made in China... 
Most likely made from recycled Coors cans...
The valve train is not a place to save $ buy the quality proven brands..
Just my $0.05...
Here's the one time I don't go on a tyrade on cheap chinese junk so I don't get banned AGAIN because I'm not a board sponsor sword swallower and I still get crap ...
YES those PRW rockers are cheap chinese junk , it appears the OP got that out of what I posted because he was surprised that I consider 400 some odd dollars CHEAP , seriously I thought the price was less , I just saw PRW and closed the link  ...
That aside I also answered his question pertaining to a performance increase which a 1.6 ratio rocker would provide , granted it wouldn't be much .
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Re: How do roller rockers improve performance?
[Re: BDW]
#1631081
06/10/14 03:35 PM
06/10/14 03:35 PM
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Joined: Jan 2003
Posts: 27,453
So Cal
autoxcuda
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 27,453
So Cal
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Quote:
From reading this the main knock seems to be the stock parts aren't really 1.5 while the rollers are 1.6.
Any reason, or maybe its already available, why not have "true" 1.5 or 1.6 stamped parts?
Usually with roller you have a choice between 1.5 and 1.6
Stamped and stock cast adjustble 273 rockers are around 1.43 to 1.45 IIRC? 
Running a high lift version of your cam is a way to net out roughly the same as with a 1.5 rocker. Valve doesn't care what ratios it takes to get it to a certain place. If it gets there, it gets there. 
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Re: How do roller rockers improve performance?
[Re: BDW]
#1631082
06/10/14 10:46 PM
06/10/14 10:46 PM
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Joined: Jan 2003
Posts: 25,200
Upper Midwest
MoparforLife
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 25,200
Upper Midwest
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Quote:
From reading this the main knock seems to be the stock parts aren't really 1.5 while the rollers are 1.6.
Any reason, or maybe its already available, why not have "true" 1.5 or 1.6 stamped parts?
You can get true 1.5 or 1.6 doctile iron adjustable rockers that are non roller. But there again you will need to get push rods for adjustable rockers with hydraulic lifters.
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Re: How do roller rockers improve performance?
[Re: JohnRR]
#1631083
06/11/14 12:38 AM
06/11/14 12:38 AM
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Joined: Feb 2010
Posts: 18,493
Granite Bay CA
Kern Dog
Striving for excellence
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Striving for excellence
Joined: Feb 2010
Posts: 18,493
Granite Bay CA
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Quote:
Here's the one time I don't go on a tyrade on cheap chinese junk so I don't get banned AGAIN because I'm not a board sponsor sword swallower and I still get crap ...
You've been banned before, too?
Last Summer I switched to a solid lifter cam. Prior to the cam swap I put in a set of aluminum rocker arms offered by Mancini racing. They are made by Harland Sharp.
Regarding the inconsistant ratios of stock rocker arms, I can report this: My cranking compression spread between the lowest cylinder and the highest tightened up when I put the new rocker arms in. My take is that the new stuff was more accurate and the result was a more evenly matched ratio for all cylinders.
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Re: How do roller rockers improve performance?
[Re: cal_gecko]
#1631084
06/12/14 05:18 AM
06/12/14 05:18 AM
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Joined: Jan 2003
Posts: 8,089
Sorrento, BC, Canada
4speeds4me
master
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master
Joined: Jan 2003
Posts: 8,089
Sorrento, BC, Canada
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Quote:
Quote:
That's what I'm saying. I know lots of guys like them, and at times, so do I. But under .550" lift, that money can be better spent getting air in and out...and as far as side loading of the valve or scrubbing the tip is concerned, how many miles do the average one of us put on these cars? In 10 years we MIGHT have worn things enough to cause an issue..
I've put 3300 miles on the Dart since the beginning of December
That's my point! 3300 miles in 6 months, so, say, 7000 for the year. That's only 70,000 in 10. I put over 50,000 on my truck in 1.5 years!
2 Demons...no, not my kids!
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