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Yeah on a CAMMED motor. To pick up 13 RWHP on a stock motor is very nice considering they don't change drivability or effect MPG at all.
I agree. That's why I was happy when I picked up 10 rwhp just switching from 1.6 s/a Promags to the 1.7 Scorpion's.
 

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well i was just sayin it was nice to pick that much up lol...so what about going from 1.5's to 1.7's on a stock motor?personally ive never used anything over a 1.6
 

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well i was just sayin it was nice to pick that much up lol...so what about going from 1.5's to 1.7's on a stock motor?personally ive never used anything over a 1.6
I had 1.52's because I did'nt want to change the springs, 1.6's when I changed the springs and now 1.7's just for the gain. I put down 299 rwhp/330 tq with the 1.6's and 309 rwhp/336 tq with 1.7's. Had I known this I would have went from stock to 1.7's and would'nt have 2 sets of Promags in the garage. I run 26918 springs, 787 retainer, stock locks, stock seat and the stock cam.
 

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but if i did go straight to 1.7's...would it be a good to go to 7/16 screw in studs?
 

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yea 11-13 isnt much..on all my gen 1 sbc motors i used cranes gold race 1.6 rr..and picked up anywhere from 20 to 30 at the mid range and top end..on a cammed motor...
That's like saying "I only found a $20 bill on the ground... well I used to find $50 bills..."

For the price, it isn't bad picking up 10 to 15 RWHP
 

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but if i did go straight to 1.7's...would it be a good to go to 7/16 screw in studs?
Yes. ARP 134-7103 7/16 stud, Trickflow TFS-30400623-8 guide plates, TF 7.200 chromoly pushrods and Scorpion scp 1026 rockers is what I used. The guide plates were a littlle close at the bottom of the U so I added about .060 to the depth very carefully with a die grinder.
 

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I read all of this and I wonder did anyone take Math classes ? If you increase the length of the rocker Arms from the 1.5 to 1.6, what ends up happening is from the trunion to the valve tip side of the rocker is longer and therefore rides out on the EDGE OF THE VALVE Stem. Ooops !! Is that new Math ? No, not new Math. That means you have to shorten the Pushrod length to get the Rocker Tip back onto the Center of the Valve Stem. Then the Valve side of the rocker is more nose up and the angle of attack on the valve stem is towards the inside of the valve or I should say closer to the middle again.
What happens when you ride out on the edge of a valve stem using a 1.6 Rocker on an Engine designed for 1.5 ? You can get away with this on a Quarter mile engine because they overhaul them every few runs, however on a daily driver, you can bend the valves, wear out the valve stem in very short time probably 20k miles or less.
The Rocker is designed by the Engineering of the Valve Degree angle. On an LS motor it's 13 Degrees and on an LT1 Motor is 23 Degrees. By Shortening the pushrod to get the valve stem into the middle you're losing lift on a 1.6 Rocker arm and therefore you're just spending money on nothing.
Your using a longer pushrod on a 1.5 for the same valve angle and increasing the valve life because of the design and the rocker tip is riding on the center of the Valve stem based on the Engineered Geometry by the Head Design.
If you buy pushrods they come in .050 lengths. Depending on your Lifter Pre-Load length you can buy .050 length longer and have the same effect as adding 1.6 rockers without spending all that money. Yes you will gain horsepower simply by adding length to your pushrod which won't affect much on your valve train because you have a safety margin in the Hydraulic Pre-Load .030 - .060.
I wish someone would have explained it to me because I had to gain this knowledge later then sooner.
Engineers get paid to design this at the time of building of the engine. You want to go outside the parameters because you're thinking your getting more horsepower, an engineer would laugh at this blog trail that's probably why many don't come here to impart wisdom because they shake their heads and ask themselves where to start explaining or even why bother ??
So just a note for all you young kids spending money for the sake of a horsepower or 2. Increase your Push rods by .050, and lower the pre-load to 1/2 a turn instead of 1 full turn. You get a safety margin that you don't get with changing Rocker Arms to 1.6.
 

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I went with 1.6 Lunati Long-Slot roller tip rocker which are NSA, so you add GM guide plates. And springs. I don’t like full roller too many needle bearings for me. This way if you ever want to do a cam swap? (I did mine while the engine was in the car.) My big “Honken” cam started to where the cam lobes out a lil. Now I’ve been running a badass baby cam with great results for like ten years no problems....
 

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I read all of this and I wonder did anyone take Math classes ? If you increase the length of the rocker Arms from the 1.5 to 1.6, what ends up happening is from the trunion to the valve tip side of the rocker is longer and therefore rides out on the EDGE OF THE VALVE Stem. Ooops !! Is that new Math ? No, not new Math. That means you have to shorten the Pushrod length to get the Rocker Tip back onto the Center of the Valve Stem. Then the Valve side of the rocker is more nose up and the angle of attack on the valve stem is towards the inside of the valve or I should say closer to the middle again.
What happens when you ride out on the edge of a valve stem using a 1.6 Rocker on an Engine designed for 1.5 ? You can get away with this on a Quarter mile engine because they overhaul them every few runs, however on a daily driver, you can bend the valves, wear out the valve stem in very short time probably 20k miles or less.
The Rocker is designed by the Engineering of the Valve Degree angle. On an LS motor it's 13 Degrees and on an LT1 Motor is 23 Degrees. By Shortening the pushrod to get the valve stem into the middle you're losing lift on a 1.6 Rocker arm and therefore you're just spending money on nothing.
Your using a longer pushrod on a 1.5 for the same valve angle and increasing the valve life because of the design and the rocker tip is riding on the center of the Valve stem based on the Engineered Geometry by the Head Design.
If you buy pushrods they come in .050 lengths. Depending on your Lifter Pre-Load length you can buy .050 length longer and have the same effect as adding 1.6 rockers without spending all that money. Yes you will gain horsepower simply by adding length to your pushrod which won't affect much on your valve train because you have a safety margin in the Hydraulic Pre-Load .030 - .060.
I wish someone would have explained it to me because I had to gain this knowledge later then sooner.
Engineers get paid to design this at the time of building of the engine. You want to go outside the parameters because you're thinking your getting more horsepower, an engineer would laugh at this blog trail that's probably why many don't come here to impart wisdom because they shake their heads and ask themselves where to start explaining or even why bother ??
So just a note for all you young kids spending money for the sake of a horsepower or 2. Increase your Push rods by .050, and lower the pre-load to 1/2 a turn instead of 1 full turn. You get a safety margin that you don't get with changing Rocker Arms to 1.6.


i believe the pushrod side is adjusted too , as to keep the valve side of the rocker acceptably over the valve, i don't think it's as important to have the tip centered on the valve as it is to have the geometry correct , incorrect geometry is whats going to cause wear.
 

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I read all of this and I wonder did anyone take Math classes ? If you increase the length of the rocker Arms from the 1.5 to 1.6, what ends up happening is from the trunion to the valve tip side of the rocker is longer and therefore rides out on the EDGE OF THE VALVE Stem. Ooops !! Is that new Math ? No, not new Math. That means you have to shorten the Pushrod length to get the Rocker Tip back onto the Center of the Valve Stem. Then the Valve side of the rocker is more nose up and the angle of attack on the valve stem is towards the inside of the valve or I should say closer to the middle again.
What happens when you ride out on the edge of a valve stem using a 1.6 Rocker on an Engine designed for 1.5 ? You can get away with this on a Quarter mile engine because they overhaul them every few runs, however on a daily driver, you can bend the valves, wear out the valve stem in very short time probably 20k miles or less.
The Rocker is designed by the Engineering of the Valve Degree angle. On an LS motor it's 13 Degrees and on an LT1 Motor is 23 Degrees. By Shortening the pushrod to get the valve stem into the middle you're losing lift on a 1.6 Rocker arm and therefore you're just spending money on nothing.
Your using a longer pushrod on a 1.5 for the same valve angle and increasing the valve life because of the design and the rocker tip is riding on the center of the Valve stem based on the Engineered Geometry by the Head Design.
If you buy pushrods they come in .050 lengths. Depending on your Lifter Pre-Load length you can buy .050 length longer and have the same effect as adding 1.6 rockers without spending all that money. Yes you will gain horsepower simply by adding length to your pushrod which won't affect much on your valve train because you have a safety margin in the Hydraulic Pre-Load .030 - .060.
I wish someone would have explained it to me because I had to gain this knowledge later then sooner.
Engineers get paid to design this at the time of building of the engine. You want to go outside the parameters because you're thinking your getting more horsepower, an engineer would laugh at this blog trail that's probably why many don't come here to impart wisdom because they shake their heads and ask themselves where to start explaining or even why bother ??
So just a note for all you young kids spending money for the sake of a horsepower or 2. Increase your Push rods by .050, and lower the pre-load to 1/2 a turn instead of 1 full turn. You get a safety margin that you don't get with changing Rocker Arms to 1.6.


i believe the pushrod side is adjusted too , as to keep the valve side of the rocker acceptably over the valve, i don't think it's as important to have the tip centered on the valve as it is to have the geometry correct , incorrect geometry is whats going to cause wear.
 

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PSA for the reply to an old post-
Pushrod cup is moved closer to the rocker fulcrum to increase lift.
The LT4 comes stock with 1.6 roller rockers.
LS is 15* valve angle.
Push rod length is altered for proper geometry.
Lifter preload does not change lift on hydraulic lifters
 

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I read all of this and I wonder did anyone take Math classes ? If you increase the length of the rocker Arms from the 1.5 to 1.6, what ends up happening is from the trunion to the valve tip side of the rocker is longer and therefore rides out on the EDGE OF THE VALVE Stem. Ooops !! Is that new Math ? No, not new Math. That means you have to shorten the Pushrod length to get the Rocker Tip back onto the Center of the Valve Stem. Then the Valve side of the rocker is more nose up and the angle of attack on the valve stem is towards the inside of the valve or I should say closer to the middle again.
What happens when you ride out on the edge of a valve stem using a 1.6 Rocker on an Engine designed for 1.5 ? You can get away with this on a Quarter mile engine because they overhaul them every few runs, however on a daily driver, you can bend the valves, wear out the valve stem in very short time probably 20k miles or less.
The Rocker is designed by the Engineering of the Valve Degree angle. On an LS motor it's 13 Degrees and on an LT1 Motor is 23 Degrees. By Shortening the pushrod to get the valve stem into the middle you're losing lift on a 1.6 Rocker arm and therefore you're just spending money on nothing.
Your using a longer pushrod on a 1.5 for the same valve angle and increasing the valve life because of the design and the rocker tip is riding on the center of the Valve stem based on the Engineered Geometry by the Head Design.
If you buy pushrods they come in .050 lengths. Depending on your Lifter Pre-Load length you can buy .050 length longer and have the same effect as adding 1.6 rockers without spending all that money. Yes you will gain horsepower simply by adding length to your pushrod which won't affect much on your valve train because you have a safety margin in the Hydraulic Pre-Load .030 - .060.
I wish someone would have explained it to me because I had to gain this knowledge later then sooner.
Engineers get paid to design this at the time of building of the engine. You want to go outside the parameters because you're thinking your getting more horsepower, an engineer would laugh at this blog trail that's probably why many don't come here to impart wisdom because they shake their heads and ask themselves where to start explaining or even why bother ??
So just a note for all you young kids spending money for the sake of a horsepower or 2. Increase your Push rods by .050, and lower the pre-load to 1/2 a turn instead of 1 full turn. You get a safety margin that you don't get with changing Rocker Arms to 1.6.
Well said
 
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