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Discussion Starter #1
Have a fairly simple 454 over .030
Comp cams xe268
Rpm intake
Summit racing 750 carb
Ported 781 heads
Th400.

As of now i have stock stamp rockers and push rods. One of my push rods got messed up because i installed it the wrong way. So i have to get a new set. But i was wondering about upgrading my rockers as well to at least a roller tip. Is it worth it for my simple setup and do i need to go with a longer rod if u ran 1.8 ratio vs the stock 1.7
 

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The rockers with a roller tip but still having a stock type pivot ball at the stud mount are a complete waste of money, forget you've ever even seen those.

A full needle bearing rocker can help power a little through a more exact ratio than stamped stock rockers, and they do lower oil temp and increase oil life due to the fact the stock pivot balls do develop a lot of heat..

Whether a longer or shorter pushrod is needed with any rocker change, either from stamped rockers to full roller, or from a ratio change is entirely dependent on what brand the rockers are and how much cam lift you have.
That's why checking and correcting valvetrain geometry is such a big, talked about issue.
 

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Anything that reduces friction and frees up valve train parts is good. While the roller rockers alone won't make a big difference on your engine they will help.
 

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Have a fairly simple 454 over .030
Comp cams xe268
Rpm intake
Summit racing 750 carb
Ported 781 heads
Th400.

As of now i have stock stamp rockers and push rods. One of my push rods got messed up because i installed it the wrong way. So i have to get a new set. But i was wondering about upgrading my rockers as well to at least a roller tip. Is it worth it for my simple setup and do i need to go with a longer rod if u ran 1.8 ratio vs the stock 1.7
Just my setup-----383 ---mild cam----now .500 lift---went from 1.5 to 1.6 rollers---i had to change to .100" longer pushrods to keep the roller in the center of the valve tip. Also at the same time i got rid of the iron heads & went with Aluminum 23* valve angle heads with angled plugs & 60cc chambers.
 

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Usually I look at mods, especially bolt-ons, from the standpoint of power gained per dollar spent. $250 (the cost of a descent set of rockers) for twenty HP would be worth it in my view. However, I'm struggling understanding how rockers of the same ratio could make that much difference.
They do add some precision and possibly some stability to the valvetrain but I'm skeptical that the "reduction of parasitic drag" frees-up 20-40 HP.
That said, I've had them on every performance engine I've owned thinking ther were just part of the package.
 

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Simple dyno tests isolating individual components are so cool! The roller tips were worth 20 or 30 peak hp right?


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If you pay attention to the graphs in the video, gain is just 11 HP up to the point it went into valve float....once they changed the springs to go along with the heaver rockers it would then RPM further and made it look like a huge gain or 20-30 HP.....but they never went back and tested with the new valvesprings and the stock rockers.....that big 20-30 HP gain past the previous float rpm would have lost a lot of it's luster.
 

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I like the video, he does a good job of explaining and demonstrating the pros and cons of roller rockers. Two important facts came out in the video. One, the roller rockers are better for their friction reduction. Two, the good quality ones also help prevent power lost to deflection.
The extra power from the upgraded rockers in the video came from the increased ratio (1.72 instead of 1.7), which came to life with proper valve springs to support the additional weight of the roller rockers..

Sharknado, if you're decide to install roller rockers (I would), make sure to measure for the correct pushrod length, it's really important! Here's another video for you. It was posted by another member a few years ago, and it really helped me out. Also, Chris Straub is an active member of this site.
 

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I like the video, he does a good job of explaining and demonstrating the pros and cons of roller rockers. Two important facts came out in the video. One, the roller rockers are better for their friction reduction. Two, the good quality ones also help prevent power lost to deflection.
The extra power from the upgraded rockers in the video came from the increased ratio (1.72 instead of 1.7), which came to life with proper valve springs to support the additional weight of the roller rockers..

Sharknado, if you're decide to install roller rockers (I would), make sure to measure for the correct pushrod length, it's really important! Here's another video for you. It was posted by another member a few years ago, and it really helped me out. Also, Chris Straub is an active member of this site.
Great video. Thanks for posting. I have a question: He was using centerline height adjustments on the stud to determine lift measurements on the valve tip. In other words, he lowered the stud height by half the gross valve lift once he established his perpendicular starting point, stating the result would be the same amount of lift. Since the rocker multiplies that, wouldn’t you need to factor that into the calculated valve movement? Or is the gross valve lift, the total linear movement at the rocker tip? If that’s the case, wouldn’t the height adjustments at the stud need to have the rocker ratio figured into the adjustments? I guess I’m just wondering why the rocker ratio didn’t play a part in the set-up?


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If you pay attention to the graphs in the video, gain is just 11 HP up to the point it went into valve float....once they changed the springs to go along with the heaver rockers it would then RPM further and made it look like a huge gain or 20-30 HP.....but they never went back and tested with the new valvesprings and the stock rockers.....that big 20-30 HP gain past the previous float rpm would have lost a lot of it's luster.
Good catch! On the stock 4.8, the rollers actually made less torque from start to 4800rpm. Also, would like to see the test start at a lower rpm. On a street car, your not going to be screaming around everywhere at 5500-6000rpm for long! Safe to assume he re-tuned the ecm for the rollers? I imagine you would have to right?




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Gross valve lift is the amount of lift at the rocker tip/valvestem tip....so rocker ratio plays no part in this initial set-up of the mid lift.

The only part rocker ratio plays in the Calculation is when you figure gross lift/valve lift from the cam's lobe lift.

If he was measuring the height location of the rocker using the pushrod cup instead of the rocker pivot, then rocker ratio would be in the picture

This may help you get your head wrapped around mid-lift set-up. Jim Miller is the guy who pioneered it.
 

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Discussion Starter #15
Man you guys are on it. I have to figure out whats important at this point. A few ponies does sound nice but at the moment i cant say i know what this set up fully feels like. I dont want to get further into chasing numbers that might not be for me. The car i had the engine was a 4 door 74 with no posi ,bad carb tuning and the timing probably was off. I just ripped the engine and trans out last night to be transplanted in a 73 2 door roller ive been working on. I will replace the single push rod and use that as a baseline. I will try to get help with the tuning and timing then work on looking for a posi setup. From there i think if i want to spice it up i will dig back into these fine lines to get a little more. But this is my first build first big block so i dont know what to expect

20200610_210023.jpg
 

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Just my opinion, but I think the roller tips would lower the side load placed on the valve and help with guide life. Roller rockers are built much more precisely and the lift will be more consistent valve to valve.
 

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Just my opinion, but I think the roller tips would lower the side load placed on the valve and help with guide life. Roller rockers are built much more precisely and the lift will be more consistent valve to valve.
Just my opinion, but I think the roller tips would lower the side load placed on the valve and help with guide life. Roller rockers are built much more precisely and the lift will be more consistent valve to valve.
Having the same thoughts
Just my opinion, but I think the roller tips would lower the side load placed on the valve and help with guide life. Roller rockers are built much more precisely and the lift will be more consistent valve to valve.
Just my opinion, but I think the roller tips would lower the side load placed on the valve and help with guide life. Roller rockers are built much more precisely and the lift will be more consistent valve to valve.
Having the same thoughts I've had a set of haland Sharp's for a while for my small block just can't seem to get them put on.. and will it make that big of a difference. But after reading all this and I have them guess it's time to get them on. Thanks for all you guys info .
 
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