Top 17 How Much Horsepower Do Roller Rockers Add 16213 People Liked This Answer

You are looking for information, articles, knowledge about the topic nail salons open on sunday near me how much horsepower do roller rockers add on Google, you do not find the information you need! Here are the best content compiled and compiled by the Chewathai27.com team, along with other related topics such as: how much horsepower do roller rockers add do roller tip rockers add horsepower, how much lift does 1.6 rockers add, roller rockers sbc, roller rockers vs standard rockers, small block chevy 16 roller rockers, are roller rockers worth it, best roller rockers for sbc, 1.5 roller rockers sbc

You can easily gain 20 horsepower with a rocker arm swap, but installing them isn’t quite as simple as removing the stock rockers and bolting on new ones. For seasoned car guys, it’s a quick process, but if you’re new to the task of setting valve lash you might want to take some notes before you tackle the project.Those results found the 1.6 rockers making more than 20 hp over the stock 1.5 rockers.The total difference in horsepower between the solid roller and hydraulic roller setup is just slightly over 8 horsepower. In fact, both cams actually made about the same ft-lbs of torque at the same RPM.

Do roller rockers make more power?

How much HP does 1.6 rockers add?

Those results found the 1.6 rockers making more than 20 hp over the stock 1.5 rockers.

Do roller lifters add horsepower?

The total difference in horsepower between the solid roller and hydraulic roller setup is just slightly over 8 horsepower. In fact, both cams actually made about the same ft-lbs of torque at the same RPM.

How much did you gain from roller rockers?

Most rocker arms are designed to increase the lift of the cam by having a positive ratio. Rocker arms are commonly designed to increase lift at the valve by about 1.3 to 1.6 times the lift at the cam.

Are roller rockers better than stock?

Besides the potential power benefits of an increase in rocker ratio, roller rockers have several additional power-adding advantages compared with a stamped rocker. The advertised ratio of aftermarket roller-tip rockers is more accurate than the claimed ratio of typical stock stamped rockers.

How long do roller rockers last?

Used on a daily driven engine with a stock valvetrain, the rockers will last approximately 20,000-30,000 miles with regular oil changes. Since you run your engines for 250,000-plus miles, you would end up replacing aluminum rockers quite often.

Can you use roller rockers on a flat tappet cam?

The two don’t necessarily need to be used together. Roller camshafts and lifters can be used in an engine that features nonroller rockers; by the same token, roller rocker arms can be used in an engine that features a flat-tappet solid or hydraulic camshaft.

What does upgrading rocker arms do?

Essentially, changing to a rocker arm ratio that is larger, is comparable to increasing the lift of your camshaft. Increasing the opening distance of both valves can usually increase power because your engine can move more air.

Why are roller rockers better?

A roller rocker has a small roller that rolls over the end of the valve stem. This virtually eliminates side load on the stem and greatly reduces wear. Another area of high friction and wear is between the rocker arm and rocker shaft.

Are roller lifters worth it?

That being said, roller lifters will offer major power advantages, along with a smoother operating engine. One reason is that roller lifters have less friction on the camshaft, which makes it easier for the cam to spin. Additionally, lobe profiles can be much more aggressive.

What do roller rocker arms do?

A roller rocker is a rocker arm that uses needle bearings (or a single bearing ball in older engines) at the contact point between the rocker and the valve, instead of metal sliding on metal. This reduces friction, uneven wear and “bell-mouthing” of the valve guide.

What rocker arm ratio do I need?

How does 1.6 rockers calculate valve lift?

of valve lift with a 1.6 rocker ratio. Valve Lift = 0.270 x 1.6 = 0.432 in. Example #2: A camshaft with 0.468 in. of valve lift with a 1.5 rocker ratio has 0.312 in.

Should I replace rocker arms?

#4 – Physical Deterioration

After removing the valve cover, look for pieces of metal below the rocker arms, as they can grind on the pivot point and valves when they are in poor condition. What is this? Degraded rocker arms should be replaced even if no other symptoms are present, because problems will soon follow.

What is the purpose of roller rockers?

A roller rocker is a rocker arm that uses needle bearings (or a single bearing ball in older engines) at the contact point between the rocker and the valve, instead of metal sliding on metal. This reduces friction, uneven wear and “bell-mouthing” of the valve guide.

What do rocker arms do?

The rocker arm is the part responsible for transmitting the movement of the camshaft towards the intake and exhaust valves of the engine, a process that occurs through the direct contact of these parts with the tappets and according to the movement of the shaft.

Free Up Horsepower in Your Small-Block with Roller Rockers

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• Most searched keywords: Whether you are looking for Free Up Horsepower in Your Small-Block with Roller Rockers Updating Drag racers have been searching for tricks to gain horsepower since day one, and there are lots of ways to do it without spending a tremendous amount of time or
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Roller-Rocker Ratio Test – Car Craft

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Rocker Arm Ratio – Super Chevy Magazine

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• Most searched keywords: Whether you are looking for Rocker Arm Ratio – Super Chevy Magazine Updating The debate over the optimum rocker arm ratio has dragged on since the invention of the pushrod V-8, but with a series of test we set out to find the best ratio. – Super Chevy Magazine
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Roller Rockers: Can a Simple Bolt-On Really Yield Big Gains? | Articles | Classic Motorsports

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• Summary of article content: Articles about Roller Rockers: Can a Simple Bolt-On Really Yield Big Gains? | Articles | Classic Motorsports Updating …
• Most searched keywords: Whether you are looking for Roller Rockers: Can a Simple Bolt-On Really Yield Big Gains? | Articles | Classic Motorsports Updating Aftermarket roller rockers claim to be a simple bolt-on that yields more horsepower. We tested that claim on an MG Midget to see if adding power to a classic is really that easy.
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Roller-Rocker Ratio Test – Car Craft

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• Summary of article content: Articles about Roller-Rocker Ratio Test – Car Craft Overall, we gained 24.1 hp and 17.3 lb-ft of torque just by bolting on a set of rocker arms, which would make a noticeable difference at the … …
• Most searched keywords: Whether you are looking for Roller-Rocker Ratio Test – Car Craft Overall, we gained 24.1 hp and 17.3 lb-ft of torque just by bolting on a set of rocker arms, which would make a noticeable difference at the … car craft takes a closer look at how to perform a Roller-Rocker Ratio Test
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Roller Rockers: Can a Simple Bolt-On Really Yield Big Gains? | Articles | Classic Motorsports

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• Summary of article content: Articles about Roller Rockers: Can a Simple Bolt-On Really Yield Big Gains? | Articles | Classic Motorsports Aftermarket roller rockers claim to be a simple bolt-on that yields more horsepower. We tested that claim on an MG Mget to see if adding … …
• Most searched keywords: Whether you are looking for Roller Rockers: Can a Simple Bolt-On Really Yield Big Gains? | Articles | Classic Motorsports Aftermarket roller rockers claim to be a simple bolt-on that yields more horsepower. We tested that claim on an MG Mget to see if adding … Aftermarket roller rockers claim to be a simple bolt-on that yields more horsepower. We tested that claim on an MG Midget to see if adding power to a classic is really that easy.
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How much HP gain from Roller Rockers? – CorvetteForum – Chevrolet Corvette Forum Discussion

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• Summary of article content: Articles about How much HP gain from Roller Rockers? – CorvetteForum – Chevrolet Corvette Forum Discussion Roller rockers DO reduce friction and can produce very minimal power gains. The biggest advantages *I* see are a more accurate rocker ratio, … …
• Most searched keywords: Whether you are looking for How much HP gain from Roller Rockers? – CorvetteForum – Chevrolet Corvette Forum Discussion Roller rockers DO reduce friction and can produce very minimal power gains. The biggest advantages *I* see are a more accurate rocker ratio, … 18, 396, big, block, c5, corvette, gain, gains, harland, horsepower, hp, increases, power, rockers, roller, sharp, How much HP gain from Roller Rockers?, Corvette, C7 Corvette, c6 corvette,C7,C6,C5,C4,C3,C2,C1, reviews,guides, parts, exhaust,performance, sale, forum, corvette forumEngine Mods – How much HP gain from Roller Rockers? – I am looking at the June Hot Rod magazine. Nice article on BB engine build up. In the side bar regarding Crane Roller rockers (page 39), they comment about a typical HP gain of 5 – 8 HP with the addition of RR based on previous engine build ups ( i assume they have…
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Do Roller Rockers Really Increase Horsepower? Engine Masters Gets Answers! – OnAllCylinders

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• Summary of article content: Articles about Do Roller Rockers Really Increase Horsepower? Engine Masters Gets Answers! – OnAllCylinders Conventional wisdom says roller rockers increase horsepower by reducing valvetrain friction—with the biggest benefits showing up at high RPM … …
• Most searched keywords: Whether you are looking for Do Roller Rockers Really Increase Horsepower? Engine Masters Gets Answers! – OnAllCylinders Conventional wisdom says roller rockers increase horsepower by reducing valvetrain friction—with the biggest benefits showing up at high RPM …
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Rockers Tested

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How much hp would i see adding 1.6 roller rockers to this setup? – Third Generation F-Body Message Boards

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• Summary of article content: Articles about How much hp would i see adding 1.6 roller rockers to this setup? – Third Generation F-Body Message Boards How much gain with 1.6 rockers depends on what you’re starting from. If going from stamped steel factory rockers then you should see a noticeable gain. …
• Most searched keywords: Whether you are looking for How much hp would i see adding 1.6 roller rockers to this setup? – Third Generation F-Body Message Boards How much gain with 1.6 rockers depends on what you’re starting from. If going from stamped steel factory rockers then you should see a noticeable gain. How,much,hp,would,i,see,adding,1,6,roller,rockers,setup,16, add, adding, bigger, cam, cylinder, gain, heads, horsepower, hot, hp, lt4, ported, putting, rocker, rockers, roller, rollerrockers, valves, How much hp would i see adding 1.6 roller rockers to this setup?, third-gen, camaro, chevy camaro, firebird, pontiac firebird, forum, discussion, bulletin board, aftermarketTech / General Engine – How much hp would i see adding 1.6 roller rockers to this setup? – i have a 355 borred 30 over with flattops with 9.8 to1 compression, ported 083 heads with 2.02 1.60 valves 1.5 rockers, lt4 hotcam, hsr intake, edlebrock headers with 3in y pipe, 700r4 with 3000stall stage 2 shift kit, 323 gears…
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Rear Wheel Horsepower Gains out of Roller Rockers??? – LS1TECH – Camaro and Firebird Forum Discussion

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• Summary of article content: Articles about Rear Wheel Horsepower Gains out of Roller Rockers??? – LS1TECH – Camaro and Firebird Forum Discussion 5 to 10 Hp is about what you should gain over stock rockers with the same ratio.. redtail2426’s Avatar. redtail2426 , 06-19-2006 05:14 PM. …
• Most searched keywords: Whether you are looking for Rear Wheel Horsepower Gains out of Roller Rockers??? – LS1TECH – Camaro and Firebird Forum Discussion 5 to 10 Hp is about what you should gain over stock rockers with the same ratio.. redtail2426’s Avatar. redtail2426 , 06-19-2006 05:14 PM. Rear,Wheel,Horsepower,Gains,out,Roller,Rockers,17, add, crane, free, gain, gains, headers, horsepower, hp, ls1, rear, rocker, rockers, roller, wheel, Rear Wheel Horsepower Gains out of Roller Rockers???, LS1Tech – Forum and Community for GM Performance Vehicles – LS1Generation III Internal Engine – Rear Wheel Horsepower Gains out of Roller Rockers??? – I was wanting to put roller rockers on my car and was wanting to know what kind of gains I would see in horsepower? The car makes 422rwhp and 389tq right now. What are the best rockers for the money, because im not rich lol and fit…
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Free Up Horsepower in Your Small-Block with Roller Rockers

Drag racers have been searching for tricks to gain horsepower since day one, and there are lots of ways to do it without spending a tremendous amount of time or money. One of the biggest downfalls of the original small-block Chevrolet design was the valvetrain, due to a lack of efficiency—lots of flat surfaces meeting other flat surfaces, leading to unnecessary friction. And even though stamped steel rocker arms were perfectly fine for daily use in your grandmother’s Caprice, they just don’t cut it considering the affordability compared to new roller rocker arms.

Whether you’re dealing with a mostly stock junkyard small-block or a highly modified race engine, rocker arms play a big role in freeing up horsepower and helping reduce friction in the valvetrain. There are numerous options for small-block Chevy roller rocker arms. First is a stamped steel rocker arm with a roller tip, which is the least expensive option. Second is an aluminum or chrome-moly steel rocker arm with the stock 1.5:1 ratio. Finally, you can opt for the same type of aluminum or chrome-moly rocker arm with a higher ratio to effectively increase the maximum valve lift. We have seen many combinations, including staggered rocker arm ratios (exhaust rockers with a higher ratio than the intake rockers or vice versa).

You can easily gain 20 horsepower with a rocker arm swap, but installing them isn’t quite as simple as removing the stock rockers and bolting on new ones. For seasoned car guys, it’s a quick process, but if you’re new to the task of setting valve lash you might want to take some notes before you tackle the project. If you’re dealing with an engine with quite a few miles on it, now would be a good time to replace the flimsy stock pushrods with a set of hardened pushrods. For our 327ci small-block Chevy, we went with a set of Comp Cams High Energy 7809 pushrods, which are 7.266-inches in length and 5/16-inch in diameter. Please note that the 7.266-inch length is designed for use with Comp Cams’ hydraulic roller retrofit camshaft. A standard small-block Chevy with a flat tappet camshaft would use a 7.800-inch pushrod, but many factors, including deck height, head gasket thickness, rocker arm ratio, and more go into determining proper pushrod length.

The rocker arms we chose for our combination are Comp Cams 1601 Ultra Pro Magnum units, featuring a 1.52:1 ratio and 3/8-inch stud fitment. These rocker arms are ideal for a high-performance build that will see plenty of street use, and that’s exactly the intention with our mild 327ci small-block. It does have a Comp Cams hydraulic roller camshaft in place, but the installation process of the new pushrods and rocker arms apply to small-block engines with flat tappet or roller tappet designs. Take a look at the quick and simple process, and check out the sidebar on adjusting valve lash if you’re using hydraulic lifters.

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1. For our 327ci small-block Chevy, we’re swapping to a set of Comp Cams 1601 Ultra Pro Magnum roller rocker arms. They feature a 1.52:1 ratio and have a super sturdy design for the ultimate in valvetrain stability. The pushrods are Comp 7809 High Energy pushrods, which measure 7.266 inches—a perfect fit for our hydraulic roller retrofit kit.

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2. In most cases, you can swap rocker arms and pushrods with the intake manifold in place, but we had our top end apart for another upgrade, so leaving the intake out of the way made it easier to see what we’re doing. In case you were wondering, the cylinder heads are Dart Pro1 Platinum, with Comp guideplates and 3/8-inch screw-in rocker arm studs.

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3. Before we start sliding pushrods into place we need to check our valvetrain geometry, as rocker arm ratio can affect the necessary pushrod length. It’s best to do this with a pushrod checker tool, which is adjustable. Checking the geometry is quick and easy—we start by coloring the valve stem with a marker.

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4. Then, it’s time to slide at least one pushrod, or your pushrod checker, into place and install the rocker arm. This works best if the engine is on top dead center on the No. 1 piston, as that means the intake and exhaust lifters are on the base circle of the cam. We adjust the valve lash and spin the engine two full rotations.

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5. After removing the rocker arm, we can take a look at the pattern left by the roller tip. The idea is for the roller to be centered on the valve stem, so our pushrod length is spot on for our combination. Be sure that the valve that you’re testing has a lifter that is pumped up, as a spongy lifter may affect the results of your geometry test.

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6. We used Comp Cams Valve Train Assembly Spray on the valve stems and also sprayed the pushrod ends and friction areas on the rocker arms. Just like any new engine part, lubrication is important on initial startup.

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7. Setting valve lash while the engine is cold is not ideal but it will get you in the ballpark and allow you to come back and fine-tune the valve lash after the engine has come up to temperature. Most hydraulic lifters are pre-loaded one-half turn past zero lash, which is the point where the rocker arm begins to apply pressure to the pushrod.

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8. Using locking rocker arm nuts, we spun our 5/8-inch wrench one half turn to achieve the proper valve lash. Then we tightened the locking Allen head fastener. The sequence in which valve lash is adjusted can be confusing, but the idea is to adjust the valve lash when the lifter is on the base circle of the camshaft.

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9. A remote starter button really comes in handy when it’s time to adjust valve lash, as you can bump the engine around without having to reach inside the car or turn the engine over by hand. One side is installed and adjusted, so now we can tackle the other side of the engine.

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10. We hated to cover up our brand-new roller rocker arms, but if you’re going to cover up the good stuff, you might as well get some cool valve covers. Comp Cams makes these tall aluminum valve covers with a black, textured finish. They were a perfect fit for our hopped up small-block, which now has a stable and efficient valvetrain.

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Adjusting Valve Lash

Valve lash adjustment is something that nearly all types of Chevrolet engines require when rebuilding or refreshing the valvetrain. It’s not as simple as tightening a bolt until it reaches a certain torque value—it requires a bit more finesse and a lot more time. Whether you’re running a solid lift or hydraulic camshaft and lifters, proper valve lash is very important to the wellbeing of your engine. Valve lash on solid lifter applications is adjusted by tightening the rocker arm nut until reaching a certain tolerance (using a feeler gauge) between the rocker arm tip and valve stem. Hydraulic lifter engines are often adjusted one-half turn past zero lash to preload the lifters. Zero lash is the point at which the rocker arm begins putting pressure on the pushrod while the lifter is on the base circle of the camshaft. There are some other opinions on how far past zero lash you should go, but in general, most camshaft companies advise one-half turn.

Valve lash adjustment offers the best results when performed at operating temperature. Old-school guys tell stories about adjusting valve lash while the engine is running, but that makes a mess and it’s a little tough with a locking rocker arm nut. Adjusting valve lash on a cold engine has drawbacks as the lifters may be a little soft, but you have to start somewhere. We like to do a baseline adjustment and then go back and fine-tune it after the engine has been brought up to operating temperature.

Valve lash can only be adjusted when the lifter is on the base circle of the camshaft. To achieve this, watch the valves open and close as you rotate the engine. When the exhaust valve is just beginning to open, you can adjust the intake valve on that cylinder. Then, rotate the engine more and adjust the exhaust valve on that cylinder once the intake valve you just adjusted is nearly closed. Do this routine for all eight cylinders and you’re ready to button it up and fire the engine.

Roller-Rocker Ratio Test

Roller rockers are not glorious parts. They look trick, but they live a pretty dismal life, working feverishly, always trying to keep things stable. Glory’s one thing, but are they worth the cost? Heck yes, if they put up the numbers, and that’s all that counts. We set out to prove it using a basically stock Chevy 350 with a Comp Cams XE 268H hydraulic cam, an Edelbrock Performer RPM intake, a 750-cfm Speed Demon carb, and a set of Trick Flow 23-degree heads. Roller rockers make power two ways. First, a rollerized rocker fulcrum reduces energy losses from mechanical friction in the drivetrain, freeing up horsepower. Second, a higher rocker-arm ratio effectively increases the camshaft’s lift and duration by holding the valves open farther and longer, allowing more air to flow through the head ports without changing the cam.To put the theory into action, we had Westech Performance Group flow a set of Trick Flow 23-degree heads, which flowed 250 cfm at 0.500-inch valve lift on the intake port and 183 cfm at 0.500-inch lift on the exhaust side (see chart).

The XE 268H cam has 0.477/0.480-inch lift with 224/230-degrees duration at 0.050, so theoretically it would not open the valves high enough with 1.5:1 rockers to even reach peak flow through the runners. Stepping up to a higher rocker-arm ratio should therefore release quite a bit of pent-up power, at least until we exceeded the flow capabilities of the head. Before you decide to up the ante with a larger-ratio roller rocker, check for piston-to-valve clearance. The higher the ratio, the higher the valves are held open at the critical points in the firing cycle when they’re near the tops of the pistons. You could have a problem if you’re already close.

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First we ran the motor with a set of stock 1.5:1 stamped rockers with pivot-ball fulcrums, and averaged 389.9 hp and 407 lb-ft of torque at 6,000 rpm. With the baseline laid down, we moved on to a set of Comp Cams 1.5:1 roller rockers. At the same 6,000-rpm peak, we made 401.1 hp and 412.9 lb-ft of torque, a gain of 11.2 hp and 5.9 lb-ft of torque.

Moving to the 1.6:1 rockers should show some gain considering the intake/exhaust lift numbers would be slightly larger; the cam’s valve-lift specs would increase to 0.508/0.512-inch lift, right in the heart of the Trick Flow heads’ peak-flow numbers (see the Math Anyone? sidebar). We were happy to see the average power levels increase again, this time by 12.5 hp and 9.9 lb-ft of torque.

For the final test, we pulled out the 1.65:1 rockers, which effectively increased max lift to a still-safe 0.524/ 0.528 inch at the peak. While power went up 0.4 hp and 1.5 lb-ft, the average didn’t show any real gain by going from the 1.6:1 to the 1.65:1 rockers because we’d exceeded the ability of the heads to flow more air.

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Overall, we gained 24.1 hp and 17.3 lb-ft of torque just by bolting on a set of rocker arms, which would make a noticeable difference at the track and in the seat of the pants. If you decide to venture from stock cast stampings to a full roller-rocker assembly, there are a couple things to remember. Again, check for piston-to-valve clearance, valvespring coil-bind, and retainer-to-valveguide interference. Also find out how much your current set of heads flow–if you’re already maxing out the cylinder-head flow capabilities with a lot of cam, you won’t see a gain like ours since you already have the additional lift in the lobes. Providing you can use the extra lift, higher-ratio roller rockers are more than worth their weight in aluminum.

Trick Flow 23-Degree Head Flow Figures Valve Lift Intake Exhaust (inches) Port (CFM) Port (CFM) 0.050 32 28 0. 100 65 70 0. 200 133 102 0. 300 188 140 0.400 226 164 0.500 250 183 0. 600 251 183 Show All

Range: 3,000-6,000 rpm TEST A RPM Torque (lb-ft) HP Stock Rockers Avg: 4,500 386.8 329.9 Min: 3,000 337.8 214.5 Max: 6,000 407.0 389.9 TEST B 1.5:1 Roller Rockers Avg: 4,500 393.4 335.6 Min: 3,000 344.6 220.6 Max: 6,000 412.9 401.1 TEST C 1.6:1 Roller Rockers Avg: 4,500 401.9 343.2 Min: 3,000 353.2 223.6 Max: 6,000 422.8 413.6 TEST D 1.65:1 Aluminum Roller Rockers Avg: 4,500 402.4 343.5 Min: 3,000 352.0 225.0 Max: 6,000 424.3 414.0 Show All

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Fast FactsWe prefer to adjust the rockers in the firing order of the motor using the Exhaust Opening, Intake Closing method (use EOIC as a shorthand memory aid). This method ensures that the lifter of the valve you’re adjusting is on the basecircle of the cam when you set the lash. To begin, put all the rockers in place and tighten the nuts or Poly-Loks enough that the arms will open and close the valves as the motor is being turned over. Start with the No. 1 cylinder intake valve and turn the motor until the exhaust valve is just beginning to open. The intake rocker should be loose; if not, loosen the nut until you can move the arm. Make sure the pushrod is seated in its pocket on the arm and tighten down the nut slowly until you can no longer move the arm or turn the push rod. This is zero-lash. Tighten the nut 1/8- to 1/4-turn more, then tighten both the nut and poly-lock with an Allen wrench another 1/8- to 1/4-turn at the same time. Do this to all the intake side rockers. To adjust the exhaust sides, again go in the firing order, but allow the intake valves to close 1/2 to 3/4 of the way before you adjust the exhaust valve.

Super Chevy Magazine

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The debate over the optimum rocker arm ratio has dragged on since the invention of the pushrod V-8. Even though Chevrolet made the decision easy for us when it engineered the small-block to run around a 1.5:1 ratio, (Comp Cams says most stock rockers are actually about 1.46:1), it’s well known that the inconsistencies of stock rockers and the friction and heat they create mean there’s power lost with them. By simply equalizing all rocker arms to a consistent 1.52:1 ratio we’ve found there’s much power to be gained. And by increasing, or more precisely optimizing, rocker ratios to alter the opening and closing events of the cam you can build even more power. SUPER CHEVY wanted to find out what the best ratio really is, but didn’t have time to debate the issue. So we thought we’d just test it instead.

Rocker DecisionsThere’s actually much more to determining which rocker arms are best for your engine besides just finding the right ratio. Stock rockers flex and make heat, but there are roller rockers made out of chrome-moly and stainless steel, as well as the familiar aluminum versions engineered to cure those problems, and then there’s shaft rockers to consider, too.

There are also some trick new rockers available with unique designs, like Crane Cams’ ingenious variable-ratio Radi-Arc rocker arms, and Crower Cams has been working on rocker arms that fix many of the problems associated with increasing the ratio and/or lengthening your valves. There’s even a trick, new electronically controlled, variable-ratio shaft rocker conversion kit called Hot Rockers for street small-blocks that we’ll tell you more about in a bit. But we wanted to cover the basics for this test. So we strapped a small-block to Westech’s Superflow 901 dyno in hopes of learning all we could from a set of rockers.

See all 7 photos See all 7 photos Westech Performance Group loaned us its 383-cid Mule for the abusing. It has Trick Flow heads, a Comp Cams 292H Performer RPM intake, MSD ignition, and a 750 Demon drinking 92-octane Unocal 76 pump gas.

Since there’s no point in only testing stuff that is way above most readers’ budgets, we chose a mild 383-cid stroker for our pulls. The engine is one of Westech Performance Group’s test mules, and they were willing to lend it to us for a day. The engine consists of a cast crank, stock 5.7 rods, and Speed Pro 9.5:1 forged pistons. Trick Flow aluminum cylinder heads with large 1.46-inch diameter springs and an Edelbrock Performer RPM intake, wearing a 750-cfm Road Demon double pumper, round out the breathing package. Westech installed a Comp Cams 292H Magnum hydraulic single-pattern camshaft to make sure that dual-pattern lobe profiles would not affect our results. Hooker 1 3/4-inch roadster headers were also used.

For the actual tests we planned to baseline the engine with stock stamped-steel rockers arms first. But Comp advised us that stock rockers are so bad, we’d probably never get a consistent pull with the relatively strong valve springs we were running, so we opted for Comp’s High Energy stamped steel rockers for the baseline pulls. Then, we switched to Comp Cams’ Magnum roller-tip chrome-moly rocker arms with a true 1.52:1 ratio. Last, we tried Comp’s full roller Hi Tech stainless steel rocker arms in both a 1.5:1 and 1.6:1 ratio. We even tried a 1.5-intake-and-1.6-exhaust-rockers combo and then planned to swap the intake and exhaust ratios to see what effect that would have. You’ll have to read on to find out about the trouble we ran into and what we learned there.

The best power-per-dollar gains came from switching the stock rockers to the roller-tip Magnum rockers with the 1.52:1 ratio. The power we gained made their under-$150 price tag worth it. The full roller 1.5s did an excellent job of pumping even more horsepower, and the reduction in oil temp that comes along with the reduced friction these rockers offer make them an easy choice.

How Rockers Add PowerThe rocker arm mechanically multiplies the cam’s lobe lift. It does this by moving the pushrod closer to the fulcrum pivot point than the valve stem tip is. A simple example would be: If the valve tip centerline is located 0.750 inch away from the rocker fulcrum pivot centerline, then a 1.5:1-ratio rocker would have the pushrod cup located 0.500 inch from the pivot centerline (.750/1.5= .500). When you increase the ratio to 1.6, yet obviously can’t move the valve or rocker arm stud, you have to move the pushrod cup closer to the pivot centerline.

See all 7 photos See all 7 photos Since the factory stamped-steel rocker arms are notoriously out of whack, we installed Comp Cams High Energy stamped rockers for our baseline because they’re built much closer to a true 1.52:1 ratio. These rockers surprised us by making over 465 hp.

So now the math (.750/1.6= 0.470) tells us that the pushrod centerline is roughly 0.030 inch closer to the fulcrum pivot. This arrangement does more than just multiply cam lift; it also multiplies the loads on the pushrod and rocker arms, making the proper ratio critical. Too much ratio will open the valves too quickly and can cause valve float at high rpm. It also multiplies the spring pressure seen on the cam lobes, so running too much ratio can wipe out a flat-tappet cam in no time. Thankfully, the cam manufacturers have studied these problems, and most won’t even sell you too much ratio unless they feel you’ve really got your act together. Since an increase in ratio also increases the loads on the rocker and its mounting stud, you should stiffen the whole assembly up in order to keep the rockers from wobbling all over the place.

That’s what stud girdles are for and why shaft rockers are so much better, even yet. A stud girdle ties all rocker arms together, distributing the loads from any one to all eight. Shaft rockers transmit the loads directly to the cylinder head without using any rocker studs at all. That’s why companies like Comp, Crane, Jesel, Crower, and T&D can offer shaft rocker ratios up to 2:1 but won’t go any bigger than about 1.8:1 with normal stud-mounted roller rockers.

Makes Your Cam Bigger, Too!An increase in rocker arm ratio nets more than additional lift. It will also change the cam’s duration characteristics. Because the increased ratio effectively speeds up valve movement, that means the valve will reach any opening height sooner than it would with a lower-ratio rocker arm. Higher ratios open the valves quicker and close the valves a little later. Since the increase is symmetrical on either side of the cam lobe centerline, a higher ratio will lengthen the overall valve timing, making your cam act bigger. The higher ratio also causes valve timing to increase proportionally as the valve opens farther (see chart above).

See all 7 photos See all 7 photos The next logical test was Comp Cams Magnum roller-tip rockers in a 1.52:1 ratio. They add power by eliminating the friction at the valve tip, and since they’re made from chrome-moly steel, they’re much stronger than stamped rockers, so flex is no longer a power limiter.

1.6 TroubleWe know from experience that a higher-ratio rocker makes more power in engines that would normally need a bigger cam. But we weren’t able to prove it this time. After installing the 1.6s, we were shocked to find the engine dropped more than 40 hp! As we explained earlier, rocker arms increase the ratio by moving the pushrod cup closer to the rocker fulcrum pivot point. That’s where our problem was. The pushrod was contacting the top of the clearance hole in the cylinder heads with the 1.6 rockers. So, you can see that swapping rocker arms involves more than just deciding what ratio to run. In fact, this problem is very hard to spot because it’s typically hidden beneath the pushrod guideplate, which is why it took us a while to find it.

Westech came to our rescue, however, and dug up some old dyno tests comparing 1.5s to 1.6s on other small-blocks. Those results found the 1.6 rockers making more than 20 hp over the stock 1.5 rockers. But, that engine was equipped with a smaller cam than this one, and it seemed to really need the additional lift and duration afforded by the higher ratio.

One cool thing we learned from this is that smaller cams really do make more low-end power. The pushrod binding caused by the 1.6 rockers bled the hydraulic lifters down and didn’t offer full lift or duration of the cam. So, in effect, we were running a much smaller cam. How small? We don’t know, but torque at 3,500 rpm with the binding pushrods jumped by almost 30 lb-ft! How can you duplicate this low-end power increase, you ask? If you’re running a very mild engine and are not worried about power above 4,500 rpm, you can reduce the rocker arm ratio instead. That may not sound right to most of you, but it helps low-end power.

You won’t get the same peak power you would with a higher-ratio rocker, but if your engine never sees that rpm, then why bother? This is a great idea for tow vehicles, 4x4s, and boats that never rev very high and need all the bottom end they can get. We know of at least one company making reduced-ratio rockers that we might try. Crower Cams has 1.2:1-small-block and 1.5:1-big-block rockers that they use to “break-in” flat-tappet cams with stiff racing springs. Whichever rocker arms you choose, do a little research before you buy. Maybe you can borrow a higher-ratio set from a friend and try them out to see if they’ll fit and, more importantly, if more ratio will make more power for you.

See all 7 photos See all 7 photos Time was short and we needed to test the full-roller rockers next. But instead of going with an aluminum rocker, we installed Comp’s top-of-the-line Hi Tech stainless rockers with a 1.5 ratio.

More Ratio Also Means More TimingAs rocker ratio is increased, so, too, is valve timing. Note how changing from the stock ratio, which is actually closer to 1.46:1, to a true 1.60:1 will increase your total valve duration by almost 20 degrees! This geometric increase is true for any cam in any engine.

COMP CAMS 292H MAGNUM HYDRAULIC CAM Degrees duration with LOBE LIFT 1.46:1 1.60:1 DIFFERENCE .006 289.5 291.1 +1.6 .020 273.9 276.0 +2.1 .050 253.4 256.2 +2.8 .{{{200}}} 188.1 195.1 +7 .400 98.6 118.1 +19.5 Show All

Rock OnThe power our 383-cid Mouse gained just by bolting on a set of Comp Cams Magnum roller tip rocker arms made this whole thing worth the price of admission. The extra power and reduced heat and friction offered by the full roller Pro Magnum rockers in a 1.5:1 ratio also really makes them an attractive bolt-on.

See all 7 photos See all 7 photos Crower has developed a new rocker arm to cure many ailments, including the one we ran into. By relocating the hole in the rocker trunion (left), Crower eliminated the problem of pushrods hitting the heads. This also moves the rocker away from the retainer and can correct the problems associated with using longer valves and rotated valve angles.

RPM STOCK 1.52 MAGNUM 1.52 PRO MAGNUM TQ HP TQ HP INCREASE TQ HP INCREASE 3600 412 283 421 289 +6 417 286 +3 3800 425 308 431 312 +4 431 312 +4 {{{4000}}} 454 346 450 342 -4 450 343 -3 4200 463 370 466 373 +3 468 374 +4 4400 467 391 474* 397 +6 476 399 +8 4600 470* 411 473 415 +4 478* 419 +8 4800 467 427 470 430 +3 477 435 +8 {{{5000}}} 462 440 460 437 -3 470 448 +8 5200 452 448 454 450 +2 461 456 +8 5400 445 458 448 461 +3 458 467 +9 5600 437 466 440 469 +3 447 477 +11 5800 423 467* 427 471 +4 436 482 +15 {{{6000}}} 408 466 415 474* +8 423 483* +17 Avg. 445 402 449 {{{405}}} +3 453 410 +8 Max* 470 467 474 474 +8 478 483 +17 Show All

Hot RockersThe new kid on the block is definitely Hot Rockers from Everoc Industries. This unique system gives your engine the best of all rocker ratios automatically. By switching ratios as you drive, Hot Rockers gives great low-end grunt and fantastic economy along with a smooth transition to a high top-end ratio for more power. Hot Rockers have basically a full-roller, shaft-mounted design that offers stability and reduced friction at the valve tip, as well. We haven’t had the chance to test Hot Rockers yet, but plan to do so soon. We’ll let you know all about them in an upcoming story. Check out www.hotrocker.com to learn exactly how this ingenious system works.

Things To CheckAnytime you plan to increase the rocker arm ratio, there are several points to check.

See all 7 photos See all 7 photos The Hot Rockers system works by shifting the fulcrum pivot of the rocker arms as you drive. All rockers will shift together, so you cannot run different ratios on the intake and exhaust. The four-position fulcrum provides ratios from 1.1:1 up to 1.75:1 (higher or lower ratios can also be specified). An ECM shifts the ratios at user-defined rpm points via an electric motor mounted on the valve covers.

Piston-To-Valve (Ptv) ClearanceIncreasing the rocker ratio adds lift that could cause the valves to tap the pistons if they were close before. Since an increase from a 1.5- to a 1.6-ratio only nets about 0.030 inch total extra valve lift, and total valve lift is not what you’re checking when you look for PTV clearance, this may not be an issue. A minimum of 0.100-inch-intake and 0.080-inch-exhaust clearance is recommended.

Retainer-To-Seal ClearanceWith your rocker arms properly lashed, check to make sure there’s about 0.030 inch clearance between the spring retainer and valve seal at max lift. This check is easiest to do with checking springs installed. You can also measure the total clearance with the valve closed and subtract your total lift to calculate the clearance. Remember to calculate lift using the new ratio.

Valve Spring Coil BindThis only requires you to find your valve spring installed height and subtract the coil bind height to find out how much lift your springs can take. It’s best to keep a minimum of 0.030 inch between a few coils if you want your springs to live.

Pushrod-To-Head ClearanceIncreasing the ratio of a rocker arm could make the pushrods hit the head or guideplate. There’s really no way to check this without installing the new rocker arms and cycling the engine by hand. Carefully check under and around the guideplate to make sure the pushrod doesn’t hit.

So you have finished reading the how much horsepower do roller rockers add topic article, if you find this article useful, please share it. Thank you very much. See more: do roller tip rockers add horsepower, how much lift does 1.6 rockers add, roller rockers sbc, roller rockers vs standard rockers, small block chevy 16 roller rockers, are roller rockers worth it, best roller rockers for sbc, 1.5 roller rockers sbc