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How do roller rockers improve performance? #1631051
06/09/14 03:36 PM
06/09/14 03:36 PM
Joined: Aug 2003
Posts: 12,589
Sacramento, CA
cal_gecko Offline OP
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Friend of mine told me I should ditch the factory shaft-mounted rockers on my 360 (non-Magnum) and go with something like this:
http://www.ebay.com/itm/PRW-SB-Mopar-273...30f&vxp=mtr

Said it would be a significant performance improvement. How does this improve performance?

Re: How do roller rockers improve performance? [Re: cal_gecko] #1631052
06/09/14 03:42 PM
06/09/14 03:42 PM
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U.S.S.A.
JohnRR Offline
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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 ...

Re: How do roller rockers improve performance? [Re: JohnRR] #1631053
06/09/14 03:55 PM
06/09/14 03:55 PM
Joined: Aug 2003
Posts: 12,589
Sacramento, CA
cal_gecko Offline OP
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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 ...




Wow .. are those considered 'cheap'? $400+ ?

Re: How do roller rockers improve performance? [Re: cal_gecko] #1631054
06/09/14 03:58 PM
06/09/14 03:58 PM
Joined: Feb 2005
Posts: 28,312
Cincinnati, Ohio
Challenger 1 Offline
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Quote:

Friend of mine told me I should ditch the factory shaft-mounted rockers on my 360 (non-Magnum) and go with something like this:
http://www.ebay.com/itm/PRW-SB-Mopar-273...30f&vxp=mtr

Said it would be a significant performance improvement. How does this improve performance?




For a LA SB I would stay with 1.5 rockers, with a good set of aftermarket 1.5s, your going to have more lift than from stock rockers and a little less friction.

I wouldn't call it significant even with 1.6 rockers.

Re: How do roller rockers improve performance? [Re: cal_gecko] #1631055
06/09/14 04:01 PM
06/09/14 04:01 PM
Joined: Jan 2003
Posts: 27,444
So Cal
autoxcuda Offline
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IIRC, you have an comp XE-268 hyd cam.

I the performance increase per dollar spend is low. Better places to spend money.

Good chance you'll need new pushrods too. And those should be custom ordered to what you exactly need after checking with a pushrod measuring setup to see if what you have now is ok. S AKA: snow ball effect.

Re: How do roller rockers improve performance? [Re: autoxcuda] #1631056
06/09/14 04:09 PM
06/09/14 04:09 PM
Joined: Aug 2003
Posts: 12,589
Sacramento, CA
cal_gecko Offline OP
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thanks guys..
AutoXCuda - good memory on the cam

yeah... snowball effect is not what I need.

I'll just drive it and enjoy it

Re: How do roller rockers improve performance? [Re: cal_gecko] #1631057
06/09/14 04:59 PM
06/09/14 04:59 PM
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Posts: 27,444
So Cal
autoxcuda Offline
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Quote:

...

yeah... snowball effect is not what I need (MORE OF).

...





Re: How do roller rockers improve performance? [Re: cal_gecko] #1631058
06/09/14 05:02 PM
06/09/14 05:02 PM
Joined: Jan 2006
Posts: 8,162
USA
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360view Offline
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It is worth noting that recent high performance pushrod engines seem to be avoiding roller rockers.

Maybe the rollers make the rocker either too heavy or less stiff.

Recent rocker designs seem to emphasize lightness and stiffness, as do pushrods.

In the book "Chrysler Engines" former chief engineer Willem Weertman writes that roller hyd lifters improved the fuel economy of the Magnum upgrade series of engines, particularly the 3.9 V6 version.

Roller rockers are certainly not new.
Rudolf Diesel's original compression-ignition engine had a roller rocker.

Re: How do roller rockers improve performance? [Re: autoxcuda] #1631059
06/09/14 05:03 PM
06/09/14 05:03 PM
Joined: Dec 2003
Posts: 16,844
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nomore65BelvJim Offline
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Reminds me of the old "Lit" song


Re: How do roller rockers improve performance? [Re: autoxcuda] #1631060
06/09/14 05:10 PM
06/09/14 05:10 PM
Joined: Aug 2003
Posts: 12,589
Sacramento, CA
cal_gecko Offline OP
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Quote:

Quote:

...

yeah... snowball effect is not what I need (MORE OF).

...










Re: How do roller rockers improve performance? [Re: autoxcuda] #1631061
06/09/14 07:06 PM
06/09/14 07:06 PM
Joined: Jan 2003
Posts: 5,888
Athens, Greece
Pyper70 Offline
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I didn't even open the link in the OP...

PRW...Chinese junk....don't grenade a motor for that stuff...I bought the 44 Source for $400 many moons ago and never installed em for fear of those exploding needle bearings...Why ditch a motor for a couple hundred bucks...I bought Harlands and it runs like a dream


Family owned 1969 Charger R/T DualQuad 440/727/GVO/3.55s
Re: How do roller rockers improve performance? [Re: Pyper70] #1631062
06/09/14 07:55 PM
06/09/14 07:55 PM
Joined: Feb 2003
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Manitoba, Canada
DaytonaTurbo Offline
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For your cam... a waste of money IMO. If you're running a solid cam or an aggressive hydraulic, then you need em. Yes there may be (very) slight gain because factory rockers often don't spec out to the true 1.5 ratio they are supposed to be, often in the 1.4 range. But that would be a terrible bang for buck upgrade in your case.

Re: How do roller rockers improve performance? [Re: JohnRR] #1631063
06/09/14 08:56 PM
06/09/14 08:56 PM
Joined: Jan 2003
Posts: 5,435
So Cal
Sinitro Offline
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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...

Re: How do roller rockers improve performance? [Re: DaytonaTurbo] #1631064
06/09/14 10:42 PM
06/09/14 10:42 PM
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Prospect, PA
BSB67 Offline
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Quote:

....often in the 1.4 range.....




And the number keeps getting lower.

Re: How do roller rockers improve performance? [Re: BSB67] #1631065
06/09/14 11:10 PM
06/09/14 11:10 PM
Joined: Jan 2003
Posts: 27,421
Balt. Md
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383man Offline
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In theory the roller has less drag to loosen up hp. How much. Maybe none. One good thing they do is put less wear on the valve guide since the roller will glide across the top of the valve easier and not put as much push on the valve to the side when opening. But if I was spending $400 or more dollars and looking for a performance gain I would not be buying roller rockers. Ron

Last edited by 383man; 06/09/14 11:11 PM.
Re: How do roller rockers improve performance? [Re: BSB67] #1631066
06/09/14 11:13 PM
06/09/14 11:13 PM
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ahy Offline
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Agree the roller tip helps at higher lifts. It reduces "scrub" across the top of the valve. Rule of thumb over .5" orso lift. With a mild cam not much help.

If you push the cam or ratio up then you have to look at stiffer springs. With stiffer springs stiffer pushrods. As you say, it snowballs.

Re: How do roller rockers improve performance? [Re: 383man] #1631067
06/09/14 11:15 PM
06/09/14 11:15 PM
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Posts: 15,197
Omaha Ne
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TJP Offline
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Quote:

In theory the roller has less drag to loosen up hp. How much. Maybe none. One good thing they do is put less wear on the valve guide since the roller will glide across the top of the valve easier and not put as much push on the valve to the side when opening. But if I was spending $400 or more dollars and looking for a performance gain I would not be buying roller rockers. Ron





Re: How do roller rockers improve performance? [Re: TJP] #1631068
06/10/14 12:10 AM
06/10/14 12:10 AM
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Upper Midwest
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MoparforLife Offline
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Here from one of the Mopar mags:

Re: How do roller rockers improve performance? [Re: MoparforLife] #1631069
06/10/14 02:35 AM
06/10/14 02:35 AM
Joined: Jan 2003
Posts: 8,089
Sorrento, BC, Canada
4speeds4me Offline
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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!


2 Demons...no, not my kids!
Re: How do roller rockers improve performance? [Re: 4speeds4me] #1631070
06/10/14 02:45 AM
06/10/14 02:45 AM
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Northern MN
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cedarmachine Offline
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If you think they are a "bolt on" part, you may be in for a surprise when the pushrods all hit the heads.

They move the pushrod seat towards the fulcrum to get the additional ratio. This usually leads to a clearance problem. Some guys bend up a few sets of pushrods before they figure this out.

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