Help with pushrod length!
#1
Staging Lane
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Help with pushrod length!
Ok this gets very confusing first time around, just want to make sure its right. I have a bolt-on motor, heads have never been taken off no internal mods UNTIL i got a TSP 228R, i did the swap with dual springs and i am covered that way, but this is where i get confused.
I have seen on ls1 tech that the 228r has a tad bit smaller base circle than the stock ls1 cam, i dont have calipers so sadly i neglected to measure the cams on the swap, i wish i did or this wouldnt be a problem.
Ok so i already purchased some chromoly push rods 7.4 length, had the motor running already but had major sewing machine, however i did the the ls1howto.com way and just torqued them down to 22ft lbs turned the motor over, torqued again and now i realize i need to do them the IC/EO way.
Here is where i am confused. on using my comp cams pushrod length checker i put sharpie on the valve tip set the push rod at 7.425 and checked swipe... my pattern was not centered like i hoped, so i put it back to 7.4 and rotated motor again and my path was nice and centered on valve tip. BUT and i am not an expert but after getting the rocker just hand tight with a 8mm socket( then attaching the torque wrench) i only got a half turn before 22 ft/lbs.
So does this seem right or am i doing something wrong? Could the sewing machine sound of been from torqueing all the rockers wrong initially?
stock rockers too.
I would just re torque them the IC/EO way and each one individual and start the beast up but i had one of my rockers spill needle bearings and am awaiting the comp cams trunnion kit.
I have seen on ls1 tech that the 228r has a tad bit smaller base circle than the stock ls1 cam, i dont have calipers so sadly i neglected to measure the cams on the swap, i wish i did or this wouldnt be a problem.
Ok so i already purchased some chromoly push rods 7.4 length, had the motor running already but had major sewing machine, however i did the the ls1howto.com way and just torqued them down to 22ft lbs turned the motor over, torqued again and now i realize i need to do them the IC/EO way.
Here is where i am confused. on using my comp cams pushrod length checker i put sharpie on the valve tip set the push rod at 7.425 and checked swipe... my pattern was not centered like i hoped, so i put it back to 7.4 and rotated motor again and my path was nice and centered on valve tip. BUT and i am not an expert but after getting the rocker just hand tight with a 8mm socket( then attaching the torque wrench) i only got a half turn before 22 ft/lbs.
So does this seem right or am i doing something wrong? Could the sewing machine sound of been from torqueing all the rockers wrong initially?
stock rockers too.
I would just re torque them the IC/EO way and each one individual and start the beast up but i had one of my rockers spill needle bearings and am awaiting the comp cams trunnion kit.
#2
Staging Lane
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I realized I did something wrong, I need to hand tighten not with a socket, so I got it to 0 lash and I got just a smudge below 1 1/4 turns to 22 ft/lbs. I mean like it's 1 3/16, is that something I need to worry about not getting the full 1 1/4?
#3
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1 1/4 turn should put you at around .062 preload. The 1 3/16 turn is close enough. What type of lifters are you running? I went with .075 on my ls7 lifters and mine sounds like a sewing machine. I'm running the ms4 and from everything I've heard it's hard to get away from the sewing machine noise with the ls1 and an aggressive cam. Also, your pushrod length will not change your swipe pattern. It only changes your preload.
#4
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I just have stock ls1 lifters. Really I thought the pushrods length also determined swipe because the 7.425 wasn't on center when I tried it. But thanks that's why I ask you guys lol. It makes me wonder if I went with a slightly longer pushrod would that give me more preload? And maybe quiet it down some?
#5
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A longer pushrod will definetly give you more preload. TSP told me to set the preload between .050"-.090" for the ls7 lifter. I'd imagine the stock ls1's are the same but hopefully someone else will chime in. If you are getting 1 1/4 turns from zero lash to 22 ft. lbs. you are on the light side. You get .050" preload for every complete turn. Like I said you are at about .060" right now with between 1 1/3-1 1/4 turns. It won't hurt to go with a .025" longer pushrod to get you to maximum preload but I doubt it will be any quieter. You'll find a ton of threads on the sewing machine noise with the aggressively cammed ls1's. I prefer to say it sounds like a solid lift cam.
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A longer pushrod will definetly give you more preload. TSP told me to set the preload between .050"-.090" for the ls7 lifter. I'd imagine the stock ls1's are the same but hopefully someone else will chime in. If you are getting 1 1/4 turns from zero lash to 22 ft. lbs. you are on the light side. You get .050" preload for every complete turn. Like I said you are at about .060" right now with between 1 1/3-1 1/4 turns. It won't hurt to go with a .025" longer pushrod to get you to maximum preload but I doubt it will be any quieter. You'll find a ton of threads on the sewing machine noise with the aggressively cammed ls1's. I prefer to say it sounds like a solid lift cam.
#7
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Two things, first you can't measure the wipe pattern the way you are doing it. Second (as stated), pushrod length with stock rockers will not alter the wipe pattern, only setting the rocker height will do that. The measurements you have taken for the wipe pattern are likely not correct.
As for the noise, an aftermarket cam (especially one with fast ramp rates like XER) will make more noise. Headers will make it louder still and for the ulitmate in noise install a FAST intake because then you hear everything. The question is whether it is just noisier and you are not used to it or whether there is something wrong. I would be less concerned if you aren't hearing metal to metal sound.
As for the noise, an aftermarket cam (especially one with fast ramp rates like XER) will make more noise. Headers will make it louder still and for the ulitmate in noise install a FAST intake because then you hear everything. The question is whether it is just noisier and you are not used to it or whether there is something wrong. I would be less concerned if you aren't hearing metal to metal sound.