Will roller rockers make that much difference?
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Back to back dyno results show that moving up to 1.6s from 1.5s and going full roller gives mid-teens power improvements. I've seen a couple of dyno graphs showing as much as 20 HP.
The power isn't linear though. Tends to be mid-range on up.
Going from 1.5 to 1.6 will add around .030" more valve lift (give or take a few), so your springs need to be up to the task. A lot of guys move up to 1.6s without changing anything else, but that approach scares me.
I'd do springs, guide plates and hardened pushrods at the same time I installed the 1.6s.
Jake
The power isn't linear though. Tends to be mid-range on up.
Going from 1.5 to 1.6 will add around .030" more valve lift (give or take a few), so your springs need to be up to the task. A lot of guys move up to 1.6s without changing anything else, but that approach scares me.
I'd do springs, guide plates and hardened pushrods at the same time I installed the 1.6s.
Jake
Thread Starter
Heel & Toe
Joined: Jun 2007
Posts: 20
Likes: 0
From: Martinsburg West Virginia
Thanks
Thanks for the info. I've read that it would help the engine run better, but also give a little horsepower gain. Just wondering because it seems like something easy to do over the weekend.
Thanks again!
Thanks again!
Le Mans Master
Joined: Jun 2006
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From: One day you're a Comet...the next day you're dust... Arkansas
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Race Director
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From: The Top of Utah
Originally Posted by Corn Flakes
Will they make a difference in sound of the car at idle, cruise, and WOT? I am aiming for louder and more sound all around. Especially at cruise.
Roller rockers will make noise if you leave the adjustment loose. Of course, so will the stock rockers.Higher ratio rocker are will make 10 - 20 more horsepower, whether they are roller or not. Roller rockers, of the same ratio, will make no perceptible, addition, power.
RACE ON!!!
Instructor
Joined: Aug 2007
Posts: 212
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From: www.C4guru.com Everywhere!
It doesn't matter if it runs well, just so it makes a racket. Roller rockers will make noise if you leave the adjustment loose. Of course, so will the stock rockers.
Higher ratio rocker are will make 10 - 20 more horsepower, whether they are roller or not. Roller rockers, of the same ratio, will make no perceptible, addition, power.
RACE ON!!!
Roller rockers will make noise if you leave the adjustment loose. Of course, so will the stock rockers.Higher ratio rocker are will make 10 - 20 more horsepower, whether they are roller or not. Roller rockers, of the same ratio, will make no perceptible, addition, power.
RACE ON!!!
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
You will see a small power gain. The engine will also run a little cooler as will your oil temp. Your stamped stock rockers are supposed to be 1.5 but actually are more like 1.42 and are not consistant. You will get a better idle if you go 1.5 for exhaust and 1.6 on the intake. This set up will net you about 10-15 HP.
Team Owner
Joined: Jun 2001
Posts: 26,196
Likes: 0
From: Orlando FL
St. Jude Donor '08-'09
A different cam with a nice lope is not going to make it any louder, it will just "sounds like it idles funny".
Your noise is going to come mostly from exhaust. You can't get much louder than just cutting the mufflers off and welding some tips on. removing all the cats adds even more noisy goodness.
Modding the engine should not make the engine that much noisier unless you got problems.
About the only "noise" addition will be from forced induction (turbo, S/C) but even then, that noise comes from those parts and not so much the engine.
Modifiy the engine for more go-fast power.... modify the exhaust for more noise (with the added benefit of some extra go-fast power)
Hope that makes more sense.
Team Owner
Joined: Sep 2002
Posts: 22,209
Likes: 12
From: OBAMA IS HITLER
i would look at upgrading rockers as a small part of a major upgrade. i wouldn't waste my time with installing 1.6 rr's just for the sake of installing them. this should be part of a comprehensive approach to be done all at once (cam/heads - heads with the correct valvetrain componentry installed, plus for L98 you'll need intake + headers/exhaust upgrades).
Last edited by Red Tornado; Aug 31, 2007 at 11:18 AM.
Instructor
Joined: Aug 2007
Posts: 212
Likes: 0
From: www.C4guru.com Everywhere!
there was ZERO sound difference when I went from 1.5 stock to 1.6 roller tips.
A different cam with a nice lope is not going to make it any louder, it will just "sounds like it idles funny".
Your noise is going to come mostly from exhaust. You can't get much louder than just cutting the mufflers off and welding some tips on. removing all the cats adds even more noisy goodness.
Modding the engine should not make the engine that much noisier unless you got problems.
About the only "noise" addition will be from forced induction (turbo, S/C) but even then, that noise comes from those parts and not so much the engine.
Modifiy the engine for more go-fast power.... modify the exhaust for more noise (with the added benefit of some extra go-fast power)
Hope that makes more sense.
A different cam with a nice lope is not going to make it any louder, it will just "sounds like it idles funny".
Your noise is going to come mostly from exhaust. You can't get much louder than just cutting the mufflers off and welding some tips on. removing all the cats adds even more noisy goodness.
Modding the engine should not make the engine that much noisier unless you got problems.
About the only "noise" addition will be from forced induction (turbo, S/C) but even then, that noise comes from those parts and not so much the engine.
Modifiy the engine for more go-fast power.... modify the exhaust for more noise (with the added benefit of some extra go-fast power)
Hope that makes more sense.
I have had straight manifolds and it was loud but I still wanted louder but it sounded AWFUL as a exaust tone. The only thing left is headers which I suppose would make it louder. This is all I am going to say because I don't want to hijack this guys thread. Thanks.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
The best you'll get is a slightly more noticable MECHANICAL sound eminating from the valve covers when moving to roller rockers. This, at times, caused the Knock Sensor to react and retard the timing, thinking the engine was experiencing detonation.
GM addressed this by going to a revised Knock Sensor and valve covers that tended to absorb the sound more.
Going from 1.5 to 1.6 rockers will add about 3 degrees (or so) of duration to the camshaft spec (PLEASE NOT LET'S GET INTO ANOTHER DEBATE ON THIS!). No, the camshaft doesn't change, but the EFFECT IS ABOUT 3 DEGREES.
On a stock cam, that small amount won't make much of a noticable change in idle quality or sound. You'd probably have to do back to back dyno or track testing to see the power increase the 1.6s give you.
Going the rocker route is one of those 'FINE TUNING" mods used to get the very last umph out of the engine. Of course, going with 1.6 roller rockers does give a certain amount of slef-esteem bragging rights.
They're a WIN-WIN move though. Just as long as you touch all the bases along the way - like springs, guide plates, pushrods, etc.
Jake
GM addressed this by going to a revised Knock Sensor and valve covers that tended to absorb the sound more.
Going from 1.5 to 1.6 rockers will add about 3 degrees (or so) of duration to the camshaft spec (PLEASE NOT LET'S GET INTO ANOTHER DEBATE ON THIS!). No, the camshaft doesn't change, but the EFFECT IS ABOUT 3 DEGREES.
On a stock cam, that small amount won't make much of a noticable change in idle quality or sound. You'd probably have to do back to back dyno or track testing to see the power increase the 1.6s give you.
Going the rocker route is one of those 'FINE TUNING" mods used to get the very last umph out of the engine. Of course, going with 1.6 roller rockers does give a certain amount of slef-esteem bragging rights.
They're a WIN-WIN move though. Just as long as you touch all the bases along the way - like springs, guide plates, pushrods, etc.
Jake
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
i would look at upgrading rockers as a small part of a major upgrade. i wouldn't waste my time with installing 1.6 rr's just for the sake of installing them. this should be part of a comprehensive approach to be done all at once (cam/heads - heads with the correct valvetrain componentry installed, plus for L98 you'll need intake + headers/exhaust upgrades).
"headers which I suppose would make it louder"
Headers / no cats and no mufflers = REAL loud.
Move to the country as your neighbours will not appreciate it
Lots of cackling from the exhaust when you back off.
Instructor
Joined: Mar 2006
Posts: 139
Likes: 0
From: Graniteville SC
rollers
I made the change and noticed nothing different below 4000 rpm. It pulls just a tad harder from 4K-6K. That in my opinion was not worth the effort or time.
The same results occurred with a head modification port and match with a set of 202 intake and 160 exhaust valves just easer breathing above 4K.
Solution: "Theres No Replacement For Cubic Displacement".....
The same results occurred with a head modification port and match with a set of 202 intake and 160 exhaust valves just easer breathing above 4K.
Solution: "Theres No Replacement For Cubic Displacement".....
Instructor
Joined: Mar 2006
Posts: 139
Likes: 0
From: Graniteville SC
Biggest
For the money and effort the biggest seat of the pants change you can make to any street car or any car is Gear Ratio going from a 2.59 to a 4.10 will make you feel like you climbed into a rocket ship and it never plays out like other quick fixes (nitrous) its always there at the beckoning call of your right foot....