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New cam .lifters.springs. from Texas speed.220/600 ..checked push rods with comp cam rod. It came to 7.38.75 with 75 preload .primed till oil came out rockers .
If I use 085 on preload it's 739.75. I would think stock should be just OK. Just to double check the rocker bolt turns down 1 and3/8 down.. With the stock push rod .
The upper end noise is VERY LOUD. To loud to let it run very long. 50 psi oil on start up. Any thoughts would help. Thanks in advance. Jack
It took mine about a half hour if run time to really quiet down. I have morel 5315's and I am running .050 preload. They are just as quiet as stock now.
How did you measure the pushrod length? Not sure I follow your numbers but the 1-3/8 turns should be around 0.078" preload. If your preload is in that vicinity with stock lifters, and the rockers don't feel overly loose (like a short pushrod), then let it idle for a few minutes to see if the lifters start to quiet down. Mine took several minutes and after the clutch installation it tool longer because I had to rotate the motor numerous times which squeezed the oil out of the lifters.
How did you measure the pushrod length? Not sure I follow your numbers but the 1-3/8 turns should be around 0.078" preload. If your preload is in that vicinity with stock lifters, and the rockers don't feel overly loose (like a short pushrod), then let it idle for a few minutes to see if the lifters start to quiet down. Mine took several minutes and after the clutch installation it tool longer because I had to rotate the motor numerous times which squeezed the oil out of the lifters.
I took the stock push rod out. Tighten the rocker down and put a mark on bolt . Put the comp cam adjustable rod in got
all the play out of it came out with 6.800+10.25×0.050+0.075=7.38.75 I hope that helps! I have let it run around
20 minutes. Still sounds very loud. Just about to pull back down. But I not sure what to look for. That why I am looking for
help. Thanks for your help Jack.
I took the stock push rod out. Tighten the rocker down and put a mark on bolt . Put the comp cam adjustable rod in got
all the play out of it came out with 6.800+10.25×0.050+0.075=7.38.75 I hope that helps! I have let it run around
20 minutes. Still sounds very loud. Just about to pull back down. But I not sure what to look for. That why I am looking for
help. Thanks for your help Jack.
Was the piston at TDC of the firing stroke when you did this? If it wasn't, the lifter may not have been on the base circle and you would get a shorter reading to zero lash. Then, when at TDC you may have slop in the valve train.
So first, make sure the piston is at TDC of the firing stroke.
Was the piston at TDC of the firing stroke when you did this? If it wasn't, the lifter may not have been on the base circle and you would get a shorter reading to zero lash. Then, when at TDC you may have slop in the valve train.
So first, make sure the piston is at TDC of the firing stroke.
To add to this..... After you're at TDC also push down on the lifter to make sure it's not hung up in the lifter tray especially if the trays are new
Was the piston at TDC of the firing stroke when you did this? If it wasn't, the lifter may not have been on the base circle and you would get a shorter reading to zero lash. Then, when at TDC you may have slop in the valve train.
So first, make sure the piston is at TDC of the firing stroke.
OK just got back to it. The first time I did it intake closed exhaust just open. I did with TDC fire stroke and got the same thing on both valves 1 3/8 turns. I put it back to gather.
Ran it for 10 minutes it does sound just a little better .not much. So I have ran it around 30 minutes all together. Ran out of time. i can not drive it .no front end.
Fwiw, I put the exact cam in a 5.3 last year from TSP. I used my stock pushrods, with no issues at all. I asked them about pushrod brands when purchasing the cam (and associated top end stuff), and they told me to not worry about pushrods. Said they sell a "ton" of these cams, and stock pushrods always work fine. Sure enough, they were perfect. It's my nephews truck, and he runs her hard every day.
Fwiw, I put the exact cam in a 5.3 last year from TSP. I used my stock pushrods, with no issues at all. I asked them about pushrod brands when purchasing the cam (and associated top end stuff), and they told me to not worry about pushrods. Said they sell a "ton" of these cams, and stock pushrods always work fine. Sure enough, they were perfect. It's my nephews truck, and he runs her hard every day.
I am back....Just put 7.425 pushrods in just for fun. Seams louder. My next step is to tear in to it.. don't mind tearing it down.
I hope it shows me what is wrong. Thanks for your help.
How did you measure the pushrod length? Not sure I follow your numbers but the 1-3/8 turns should be around 0.078" preload. If your preload is in that vicinity with stock lifters, and the rockers don't feel overly loose (like a short pushrod), then let it idle for a few minutes to see if the lifters start to quiet down. Mine took several minutes and after the clutch installation it tool longer because I had to rotate the motor numerous times which squeezed the oil out of the lifters.
I thought that 1 full turn equals something like .078" or .079" of preload when factoring in the 1.7 ratio rocker arm? Not the .047" per 1 turn that was posted by the guy that worked at Thunder Racing years ago since it does not take the rocker arm ratio into the equation.
I am honestly not sure what is in fact correct and would like to know which is accurate when determining lifter preload and whether or not the ratio of the rocker arm needs to be factored in or not.
Last edited by StealthFormula; 09-14-2017 at 01:46 PM.
If the distance between threads of the bolt is .047 (I don't recall and too lazy to look up), then you add another .047/1.7 to this, which comes out to a total of .075. This gives the distance that the point where the rocker touches the pushrod moves, for one turn of the bolt.
I thought that 1 full turn equals something like .078" or .079" of preload when factoring in the 1.7 ratio rocker arm? Not the .047" per 1 turn that was posted by the guy that worked at Thunder Racing years ago since it does not take the rocker arm ratio into the equation.
I am honestly not sure what is in fact correct and would like to know which is accurate when determining lifter preload and whether or not the ratio of the rocker arm needs to be factored in or not.
The rocker bolt is an 8mmX1.25 thread. So each turn it will move 1.25mm. You divide by 25.4 to get inches. So each turn will advance the bolt 0.049 inches. However, when you tighten the bolt, it will advance then stop but as you continue to tighten until you reach the torque value the bolt isn't actually putting any more preload into the lifter, rather you are stretching the bolt itself. When I played with this method, which isn't very accurate, I found that if it takes one turn to go from zero lash to 22 lb-ft, 1/3 turn is required to reach the torque value and there is no further preload added to the lifter.
So now, one turn to reach 22 lb-ft is really 2/3 turn of bolt advance that is actually preloading the lifter or 0.049 X 2/3 or 0.033 inches. 2 turns to reach 22 lb-ft would actually be 1-2/3 turns or 0.0656 inches.
Now you have to use parallel triangles to figure out how much the bolt advance preloads the lifter. The ratio is 2.7/1.7 or 1.588. So in the case of 1 turn to reach 22 lb-ft, the preload is 0.052" (0.033 X 1.588) which is close to the 0.049" stated based on thread pitch. As you can see, it is a little more complicated than everyone thinks and that isn't even taking into account the fact that stock lifters are not a 1.7 ratio on the seat they are 1.54.
Here is a long thread on the subject, unfortunately the photos are missing due to photobuckets new rules but the test and explanations are still there.
The rocker bolt is an 8mmX1.25 thread. So each turn it will move 1.25mm. You divide by 25.4 to get inches. So each turn will advance the bolt 0.049 inches. However, when you tighten the bolt, it will advance then stop but as you continue to tighten until you reach the torque value the bolt isn't actually putting any more preload into the lifter, rather you are stretching the bolt itself. When I played with this method, which isn't very accurate, I found that if it takes one turn to go from zero lash to 22 lb-ft, 1/3 turn is required to reach the torque value and there is no further preload added to the lifter.
So now, one turn to reach 22 lb-ft is really 2/3 turn of bolt advance that is actually preloading the lifter or 0.049 X 2/3 or 0.033 inches. 2 turns to reach 22 lb-ft would actually be 1-2/3 turns or 0.0656 inches.
Now you have to use parallel triangles to figure out how much the bolt advance preloads the lifter. The ratio is 2.7/1.7 or 1.588. So in the case of 1 turn to reach 22 lb-ft, the preload is 0.052" (0.033 X 1.588) which is close to the 0.049" stated based on thread pitch. As you can see, it is a little more complicated than everyone thinks and that isn't even taking into account the fact that stock lifters are not a 1.7 ratio on the seat they are 1.54.
Here is a long thread on the subject, unfortunately the photos are missing due to photobuckets new rules but the test and explanations are still there.
Thank you for the very detailed explanation. It is certainly more complicated that most think. I think this is good info to have out there because through my searches there is a lot of junk information on this site related to measuring pushrod length and preload, etc.
Between it being a Monday morning and work kicking my *** thus far today my brain is not working 100% so I had to read over your explanation a few times. If I am grasping everything correctly, the following is true as an approximation:
1 full turn on the rocker bolt (that does not include any torqueing) is equal to ~.078" preload on the lifter with a 1.7 ratio rocker.
1 full turn on the rocker bolt (which includes torqueing the bolt so figuring ~.33 of that 1 turn is for torqueing) is equal to approximately .052" (very close to that .049" figure) of preload on the lifter with a 1.7 ratio rocker.
Thank you for the very detailed explanation. It is certainly more complicated that most think. I think this is good info to have out there because through my searches there is a lot of junk information on this site related to measuring pushrod length and preload, etc.
Between it being a Monday morning and work kicking my *** thus far today my brain is not working 100% so I had to read over your explanation a few times. If I am grasping everything correctly, the following is true as an approximation:
1 full turn on the rocker bolt (that does not include any torqueing) is equal to ~.078" preload on the lifter with a 1.7 ratio rocker.
1 full turn on the rocker bolt (which includes torqueing the bolt so figuring ~.33 of that 1 turn is for torqueing) is equal to approximately .052" (very close to that .049" figure) of preload on the lifter with a 1.7 ratio rocker.
Basically, yes. Once the bolt bottoms out it won't apply much more lifter preload. So any turns you are counting must be from zero lash to the bolt bottoming out on the head and shouldn't include any bolt rotation required to reach the torque value.
Per the diagram below, if A=1 and B=1.7, the ratio is 1.7. However, when you tighten the rocker bolt the rocker pivots about the valve stem contact point and not the bolt. So the distance to the pushrod is A+B from the valve stem or 2.7 and the distance to the bolt from the valve stem is B or 1.7. That is where the 2.7/1.7 comes from which is the 1.588. Again, this is an approximation. The best thing is to measure the pushrod at zero lash and then add the preload. The best measurement of preload is with a dial indicator.
Basically, yes. Once the bolt bottoms out it won't apply much more lifter preload. So any turns you are counting must be from zero lash to the bolt bottoming out on the head and shouldn't include any bolt rotation required to reach the torque value.
Per the diagram below, if A=1 and B=1.7, the ratio is 1.7. However, when you tighten the rocker bolt the rocker pivots about the valve stem contact point and not the bolt. So the distance to the pushrod is A+B from the valve stem or 2.7 and the distance to the bolt from the valve stem is B or 1.7. That is where the 2.7/1.7 comes from which is the 1.588. Again, this is an approximation. The best thing is to measure the pushrod at zero lash and then add the preload. The best measurement of preload is with a dial indicator.
I am back again... tore top end apart. The only thing I found so far. I have put 5.7 head gasket on. I have a lq4 6.0
Stupid ME .. I am not sure that would make it sound like upper noise. Not sure if it would make noise. Stupid me.
09-03-2017, 04:37 PM
Upper valve noise very very loud 
