.100+ lifter preload on lifters?
Thread Starter
Melting Slicks
Joined: Nov 2011
Posts: 3,187
Likes: 266
From: Virginia
When the duration over 224 or lift above .600 the aftermarket cam is ground with a smaller base circle usually .060 smaller than stock. Which in turn requires a slightly longer pushrod. Ls7 lifters are forgiving and typically can take a 7.400 pushrod with aftermarket cams. I have a BTR stage 2 v1 with 7.425 pushrods and Che Trunnion kit. Car has 20k miles and has that typical sewing machine sound.
Instructor
Joined: Aug 2021
Posts: 140
Likes: 11
From: Chicago
We have the exact same setup. Does yours sound anything like mine? The motor sounds good except for a consistent pecking noise on drivers side coming from either cylinder 1 or 3
https://youtu.be/yNZ9rWtaR5s
https://youtu.be/yNZ9rWtaR5s
looks like you have kooks. Did they give you the stage 8 locking bolts?
Thread Starter
Melting Slicks
Joined: Nov 2011
Posts: 3,187
Likes: 266
From: Virginia
When my car was bone stock I had this same loud tick at the same location. When the cam was done the motor was pulled and got all new bearings plus the heads needed a valve job for some reason.
I cannot figure out for the life of me what is causing this tick. Lifters and trays were changed, cam, springs, pushrods and rocker trunnions… only things left would be the rockers themselves, bad valve or lifter bore issue… so aggravating.
what it sounds like is the same sound if a pushrod was too short but I’ve checked and that’s not the case.
Instructor
Joined: Aug 2021
Posts: 140
Likes: 11
From: Chicago
I wish that’s all it was but it’s 100% not exhaust related… and yea I have the stage 8 bolts on.
When my car was bone stock I had this same loud tick at the same location. When the cam was done the motor was pulled and got all new bearings plus the heads needed a valve job for some reason.
I cannot figure out for the life of me what is causing this tick. Lifters and trays were changed, cam, springs, pushrods and rocker trunnions… only things left would be the rockers themselves, bad valve or lifter bore issue… so aggravating.
what it sounds like is the same sound if a pushrod was too short but I’ve checked and that’s not the case.
When my car was bone stock I had this same loud tick at the same location. When the cam was done the motor was pulled and got all new bearings plus the heads needed a valve job for some reason.
I cannot figure out for the life of me what is causing this tick. Lifters and trays were changed, cam, springs, pushrods and rocker trunnions… only things left would be the rockers themselves, bad valve or lifter bore issue… so aggravating.
what it sounds like is the same sound if a pushrod was too short but I’ve checked and that’s not the case.
Thread Starter
Melting Slicks
Joined: Nov 2011
Posts: 3,187
Likes: 266
From: Virginia
Instructor
Joined: Aug 2021
Posts: 140
Likes: 11
From: Chicago
how’s the car drive? Seems to idle ok
Thread Starter
Melting Slicks
Joined: Nov 2011
Posts: 3,187
Likes: 266
From: Virginia
Car drives great. It pulls hard, no misfires or idle issues. The street manners of that cam are really impressive as well
Instructor
Joined: Aug 2021
Posts: 140
Likes: 11
From: Chicago
I put a stethoscope on the injector, isn’t coming from there. It most likely is lifter related but it’s just really odd that it’s in the same spot as when it was stock…
Car drives great. It pulls hard, no misfires or idle issues. The street manners of that cam are really impressive as well
Car drives great. It pulls hard, no misfires or idle issues. The street manners of that cam are really impressive as well
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Thread Starter
Melting Slicks
Joined: Nov 2011
Posts: 3,187
Likes: 266
From: Virginia
I wouldn’t stress then too much. That’s how my car drives. I was worried with it being 5 degrees positive overlap but it drives so close to stock it’s crazy. I wish I went with a higher stall than the 2800-3000 circle d but aside from that the car is a great daily driver.
I’m trying not to stress too hard about the ticking noise however it’s hard not too because it’s all I hear when I drive. With the windows up and radio low/off it’s quiet noticeable. I’ve been either turning up the music or trying to keep my rpm’s higher because it sounds better above 3k rpm’s.
Lol
Instructor
Joined: Mar 2019
Posts: 174
Likes: 18
From: Sacramento
I have the BTR stage 2 for my LS2. The 7.4 pushrods that came with the kit were too short and noisy. I measured 7.45 for the low end of preload on a LS7 lifter. I'm at about 0.75-.080 preload now with a 7.45 push rod. No more noise.
You need to count the turns from zero lash till with the rocker arm bottoms out on the head. DO NOT TORQUE the bolt down when you are doing this.
I use 0.0189 preload per 1/4 turn.
You need to count the turns from zero lash till with the rocker arm bottoms out on the head. DO NOT TORQUE the bolt down when you are doing this.
I use 0.0189 preload per 1/4 turn.
Thread Starter
Melting Slicks
Joined: Nov 2011
Posts: 3,187
Likes: 266
From: Virginia
I have the BTR stage 2 for my LS2. The 7.4 pushrods that came with the kit were too short and noisy. I measured 7.45 for the low end of preload on a LS7 lifter. I'm at about 0.75-.080 preload now with a 7.45 push rod. No more noise.
You need to count the turns from zero lash till with the rocker arm bottoms out on the head. DO NOT TORQUE the bolt down when you are doing this.
I use 0.0189 preload per 1/4 turn.
You need to count the turns from zero lash till with the rocker arm bottoms out on the head. DO NOT TORQUE the bolt down when you are doing this.
I use 0.0189 preload per 1/4 turn.
and you lost me there on that second part. Don’t you hand tighten the rocker bolt until you reach 0 lash then count the turns from there to reach 22ft lbs?! Also did your cam sound anything like mine in the video?
Instructor
Joined: Mar 2019
Posts: 174
Likes: 18
From: Sacramento
Stock heads? If so that’s really surprising that it took a 7.450 to get you to .075-.080 preload.
and you lost me there on that second part. Don’t you hand tighten the rocker bolt until you reach 0 lash then count the turns from there to reach 22ft lbs?! Also did your cam sound anything like mine in the video?
and you lost me there on that second part. Don’t you hand tighten the rocker bolt until you reach 0 lash then count the turns from there to reach 22ft lbs?! Also did your cam sound anything like mine in the video?
From zero lash I got about a little over four, 1/4 turns. I say about 4.25. So 4.25 x .0189 = .080
You hand tighten the rocker to zero lash (use the two-finger method. You Tube) then count the turns after zero lash until the rocker arms bottoms out. That is your preload. DO NOT TORQUE to 22ft lbs yet. Stop after the rocker arm bottoms out. If you count the turns it takes to torque the rocker arm down, your preload measurement will be off because you are only stretching the bolt after it bottoms out. You are no longer adding preload to the lifter after that point. Torque to 22ft lbs on final assembly after you have the correct preload.
I asked my machine guy and he says off the shelf parts only get you in the ballpark range. You have to measure in order to get the correct preload because of manufacturing tolerances in the parts my not be the same as the next part.
Race Director
Joined: Mar 2011
Posts: 13,262
Likes: 3,151
From: SW Florida
2021 C6 of the Year Finalist - Modified
Just my opinion, but at 22 ft/lb of torque, I don't think there is very much actual bolt stretch at all. 22 ft/lb is not alot of pressure.
I guess if you wanted to get real **** about it, you could count the amount of bolt turns at 10 ft/lb, and then continue torqueing the bolt to the required 22 ft/lb.
I guess if you wanted to get real **** about it, you could count the amount of bolt turns at 10 ft/lb, and then continue torqueing the bolt to the required 22 ft/lb.
Thread Starter
Melting Slicks
Joined: Nov 2011
Posts: 3,187
Likes: 266
From: Virginia
Yup, my engine sounded just like yours. I contacted BTR about the noise because it was their kit. No response. I knew the noise was because my pushrods were too short so I measured about 8 times using a set 7.375 and 7.425 + the 7.400 pushrods plus a push rod length checker. I came to 7.450. I have stock 243 heads.
From zero lash I got about a little over four, 1/4 turns. I say about 4.25. So 4.25 x .0189 = .080
You hand tighten the rocker to zero lash (use the two-finger method. You Tube) then count the turns after zero lash until the rocker arms bottoms out. That is your preload. DO NOT TORQUE to 22ft lbs yet. Stop after the rocker arm bottoms out. If you count the turns it takes to torque the rocker arm down, your preload measurement will be off because you are only stretching the bolt after it bottoms out. You are no longer adding preload to the lifter after that point. Torque to 22ft lbs on final assembly after you have the correct preload.
I asked my machine guy and he says off the shelf parts only get you in the ballpark range. You have to measure in order to get the correct preload because of manufacturing tolerances in the parts my not be the same as the next part.
From zero lash I got about a little over four, 1/4 turns. I say about 4.25. So 4.25 x .0189 = .080
You hand tighten the rocker to zero lash (use the two-finger method. You Tube) then count the turns after zero lash until the rocker arms bottoms out. That is your preload. DO NOT TORQUE to 22ft lbs yet. Stop after the rocker arm bottoms out. If you count the turns it takes to torque the rocker arm down, your preload measurement will be off because you are only stretching the bolt after it bottoms out. You are no longer adding preload to the lifter after that point. Torque to 22ft lbs on final assembly after you have the correct preload.
I asked my machine guy and he says off the shelf parts only get you in the ballpark range. You have to measure in order to get the correct preload because of manufacturing tolerances in the parts my not be the same as the next part.
Thread Starter
Melting Slicks
Joined: Nov 2011
Posts: 3,187
Likes: 266
From: Virginia
When I had my cam put in I had them pull the motor and send it off to a machine shop to get checked and have all the bearings replaced because I had some metal shavings in my oil. The machine shop ended up doing a valve job, I don’t know the exact reason why. My guess is there was too much movement in the valves and damaged the seats. So it would make sense that maybe I have a worn valve guide. I hope that’s not the case but that would be my guess…
Melting Slicks
Joined: Jun 2014
Posts: 2,236
Likes: 498
From: NJ
Sorry Turbo6TA, you are correct. I understand now. 3/4 of a turn will not allow enough preload; so increasing pushrod length will bring the rocker arm further away from the pedestal thereby increasing the preload when torqued to spec.
Thread Starter
Melting Slicks
Joined: Nov 2011
Posts: 3,187
Likes: 266
From: Virginia
So guys what would you do if you were in my situation?
I took the car back to the shop that did the install and they are gonna pull the head back off and check things out but my guess is they prob won’t find any obvious issues… So where do I go from here? Get a different set of lifters? I was thinking maybe try to Morel drop-ins. Heck I even thought about just buying a brand new bare head along with the lifters.
I just want the motor to sound normal but that’s been a ghost I’ve been chasing since the day I bought this car. So frustrating
I took the car back to the shop that did the install and they are gonna pull the head back off and check things out but my guess is they prob won’t find any obvious issues… So where do I go from here? Get a different set of lifters? I was thinking maybe try to Morel drop-ins. Heck I even thought about just buying a brand new bare head along with the lifters.
I just want the motor to sound normal but that’s been a ghost I’ve been chasing since the day I bought this car. So frustrating
Race Director
Joined: Oct 2004
Posts: 12,864
Likes: 4,668
I wouldn’t stress then too much. That’s how my car drives. I was worried with it being 5 degrees positive overlap but it drives so close to stock it’s crazy. I wish I went with a higher stall than the 2800-3000 circle d but aside from that the car is a great daily driver.