02-19-2024, 10:41 PM | #1 |
Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016
Location: US
Posts: 1,213
|
Destroyed Cam Motion Cam and Johnson Lifters
So I don't get on the forums much anymore, especially since sadly everything has been taken over and is now controlled by Facebook and Google. But I recently heard a noise so I decided to pull the motor and tear it down.
So I heard what I was hoping was a belt tensioner but after further inspection with a stethoscope, I confirmed it was the classic cam lobe chirp noise. Before I pulled the motor and tore it down, I could tell with the stethoscope it was somewhere around the #4 cylinder. So I got the engine pulled and pulled the passenger side head (I couldn't pull the drivers because I don't have a 13mm hex head socket and didn't want to risk using my 14mm hex head socket for the driver's special head bolt). #4 definitely is the worst, and by a good bit compared to the others although all of them still didn't look great but more ok. So I have only had this Cam Motion cam in for less than 15k miles. Its a 226/238-114-.630/620 (XA226/350-XA238/345-14+3) and I believe it is on a stock/OEM 5150 core. Before I had a TSP with basically the same specs and both have been running on PAC .660 dual springs. I have been through 3 different size pushrods lengths hoping that I could get it more quiet but I was within the recommended preload. I switched from the TSP to Cam Motion cam after my stock valve seats got destroyed. So I kept the same PAC .660 dual springs and Johnson lifters and switched to the Cam Motion cam. The oil had also been loading up with metals as well. Thankfully the rest of the engine appears to be fine. The valvetrain, rocker arms, pushrods, springs all seem ok. I did have a very small piece on the very bottom of my PAC springs break when I had the TSP cam. So at this point I really think I want to just go back to stock. If I could find it, I would get the GMPP cam and not worry about it anymore but you can't find it along with the converter they used to have for the 8L90. I was looking at Katech stuff as well. I know BTR is making a lot of claims about Spintrons and valve bounce, which I am glad they are talking about it at least but not sure if they have really done the testing and development for a stable valvetrain. If I decide not to go back to stock and get another cam, I am going to flycut for more clearance so this at least gives me an opportunity to do that. I just wish it didn't cost so much to tear these things down. You can easily spend almost $500 in gaskets, bolts, and hardware if you want to take the heads off and open it up and rebuild it "right". I am using a Cometic 0.028 gasket to get my compression as high as possible and they alone are almost $250 which I know reusing them is a controversial subject and I almost think it could work, but with the work it takes to pull the engine it probably is worth the extra money to buy new ones. I think after you have torqued it and ran it up to temp and cycle it, the rubber/viton overmold comes off and I would be worried about the seal after that. |
02-19-2024, 11:31 PM | #2 |
Drives: Chevrolet Camaro Join Date: Feb 2020
Location: AL
Posts: 52
|
Geez this is disheartening. You used all the good parts and still ate the cam. It almost looks like you got a bad cam core?
Were these the normal 2110 Johnsons or the short travel? |
02-20-2024, 12:20 AM | #3 |
Drives: 2018 Camaro ZL1 A10 Join Date: Feb 2022
Location: Dubai, UAE
Posts: 68
|
Sorry to hear about your misfortune. I had a similar failure in 2022 with a TSP cam and Morel lifter. I attributed the failure to either inferior component material (lifter & cam), or using oil that is not compatible with E85
What engine oil were you using & how often were you changing it during those 15k miles? |
02-20-2024, 12:42 AM | #4 | |
Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016
Location: US
Posts: 1,213
|
Quote:
I believe the Cam Motion cam used the chromium 5150 core, but yes maybe it was a one-off bad core or something else was off. If I do decide to upgrade and fly cut, I really want to go with an OEM LS7 style lifter. I realize the LS7 are all the same vs LS7 lifters are not all created equal is a very controversial subject probably because lifters are hard to tell apart besides just looking at the visuals. But anyway, BTR keeps saying they have done hundreds of engine dynos tests with their 230 cam using LS7 lifters and I believe conical, non-dual springs as well. Being able to go to an OEM style lifter and a more OEM like valve spring (non-dual spring) with less pressure is really appealing to me if it will work correctly. I am hoping the less spring pressure along with one spring and the OEM style lifter will help with noise so the car doesn't sound so broken. It was getting to where the sewing machine noise was actually louder than the exhaust. Looking at the front of the car, that is all you could hear, the sewing machine/clicking noise was so loud you couldn't even almost hear the exhaust. |
|
02-20-2024, 12:49 AM | #5 | |
Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016
Location: US
Posts: 1,213
|
Quote:
So I do run E85 (usually around 60-70% alcohol content) basically 100% of the time but I never really gave much thought into oil compatibility with alcohol fuels or that it could be causing an issue. Are you concerned about dissolved water in the oil/fuel from alcohol content or what? |
|
02-20-2024, 01:27 AM | #6 | |
Drives: 2018 Camaro ZL1 A10 Join Date: Feb 2022
Location: Dubai, UAE
Posts: 68
|
Quote:
I also started changing my oil every 2-3k miles, which I believe is the general recommendation from various tuners when running E85 |
|
02-20-2024, 01:44 PM | #7 |
Drives: 2016 1SS NFG A8 Join Date: Aug 2017
Location: 46804
Posts: 6,953
|
That is wild..first I have heard of a Cam motion / Johnson lifter combo failure.
__________________
2016 NFG 1SS A8
Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA |
02-20-2024, 02:35 PM | #8 | |
Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016
Location: US
Posts: 1,213
|
Quote:
|
|
02-20-2024, 02:43 PM | #9 | |
Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016
Location: US
Posts: 1,213
|
Quote:
I always felt that my engine was too noisy and after going through the different pushrods lengths I just kind of gave up with the noise. It was bad enough you could clearly hear it driving inside the car with the radio off, even during highway speed. The damage isn't isolated enough on the #4 intake for me to think it was something wrong with that lifter/pushrod/rocker/spring combo, but some of the other lobes don't look that bad, but I am going to get the other head off tonight and get more pictures. I need to also check to see if any of the pushrods are bent and check the springs as well and get them off and I can test them at work to see if anything is off on them. |
|
02-20-2024, 03:41 PM | #10 | |
Snackbar Tuning
Drives: 2023 SGM ZL1 Join Date: Oct 2016
Location: Florida
Posts: 1,288
|
Quote:
__________________
GM Gen V Calibrator
|
|
02-20-2024, 10:07 PM | #11 |
Drives: 2018 Camaro ZL1 A10 Join Date: Feb 2022
Location: Dubai, UAE
Posts: 68
|
You are right that DI40 is the correct oil for LT engines. However when I emailed them and told them about my power level, yearly mileage and type of racing I am doing they recommended DT50 as it can "handle the abuse". I went with DT40 though because my bearing clearances are similar to stock
|
02-21-2024, 12:26 AM | #12 |
Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016
Location: US
Posts: 1,213
|
So I was trying to get the cam out tonight to get a closer look at the lobes, but I can't get the cam retainer plate off, it broke one Torx bit and now I am scared I am going to round it off.
I really hope I didn't use red loctite last time I put my cam in, I am kind of thinking I did for whatever reason or I was out of blue because these bolts are definitely in there and I can't feel any of them budging. I am using a cheap HF Pittsburg T45 3/4 drive socket so I think first thing I am going to go invest in CR-MO impact rated T45 socket first and see if that gets me anywhere first, then think of something else after that. I double checked service info and it definately calls for blue loctite on the cam retainer bolt threads and not red, calls for GM PN: 12345382, which is apparently blue "medium strength". Anyway, some of the lifters definitely have some roller damage as well. Some of them feel very non-smooth and gritty/grindey, and some feel smooth and fine. Seems like the ones that feel gritty/grindey have good looking roller surfaces and corresponding cam lobes and the ones that feel smooth pitting and wear on the rollers and corresponding cam lobes. I also measured the lifter bores and they are fine, actually about .002 lower than the MIN diameter limit but I am measuring with snap gages so I probably aren't getting that accurate measurement to get into the thousands with snap gages and calipers. The lifter trays are also pretty loose and won't hold the lifters anymore, they fall out or turn side to side. |
02-21-2024, 06:43 AM | #13 |
Snackbar Tuning
Drives: 2023 SGM ZL1 Join Date: Oct 2016
Location: Florida
Posts: 1,288
|
Man what a bummer to hear
__________________
GM Gen V Calibrator
|
02-21-2024, 09:38 AM | #14 |
Drives: 17 hyper blue 2SS M6 Join Date: Mar 2018
Location: NorCal
Posts: 653
|
I was just having the same issue, ended up using an impact driver and was able to bust them loose. Didn't feel comfortable using a hammer on an aluminum block but I had to eventually man up and swing it. Immediately ordered a new set of bolts.
|
|
|
Post Reply
|
|
|