4200 Vortec cam wear pattern

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363
Location
Va
I replaced all the lash adjusters as I had an occasional cold start tick. The tick is now gone, but I wanted to ask I about the cam wear pattern and is this a normal pattern for this engine? This is my first OHC motor and have owned since new....mileage is 287K. The lobes feel perfectly smooth, only have that narrow wear mark.

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i6pwr

Thread starter
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363
Location
Va
Thanks.. I used M1 5W-30 from about the 3rd OC up to about 200K. Around that time I had an occasional lash adjuster tick and opened it up, cleaned some of the adjusters and replaced a weak one. All was good until last winter and started a tick on a single adjuster. I tried a few other brands around 200K, some PWB, M1 HM, Syntec, and Rotella. I used some T6 for about 40-50K miles with good results and have recently changed over to PP 5W-30. Brief history... I installed an oil catch can at about 240K. This worked fine for a few OC's...was catching maybe 6oz per 5K miles, then I was catching less and less. I started hearing other valvetrain noises and when I plugged the large port on the valve cover to test.. which seems to quiet the tick, I didnt have any vacuum. The catch can was clean, but there was a fine filter in the lid that was restricted so that seemed to plug my PCV system. I have since remedied that, I did see some carbon on the piston crown, trying to clean that over time. So I replaced all the lash adjusters which cured the cold start tick, now looking to use top tier gas and either PP, PUP, or Amsoil and try to keep all the parts free of any build up. Yes, that is the original head gasket.....now you kinda have me worried....lol. Looking at the cam lobes, was curious about the progressive wear pattern towards the middle of the wear pattern. Looks somewhat normal, but curious nonetheless. Motor is a 2002 model year.
 
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8,048
Location
Michigan
The lobes look great for 287k miles! The Atlas engine family has never gotten a lot of attention from the performance aftermarket, but I talked to a drag racer in Kalamazoo, Michigan once that modified a 4200 for his dragster. He destroked it to 3.8 liters, ported the head, raised the compression, got long duration cams, and put 3 2-barrel carbs on it. He ended up running in the 8's at 170+mph with the engine buzzing 10k rpm in the lights.
 
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Messages
1,401
Location
Sask, Canada
Looks good!! I don't recall Atlas motors having issues with cams or head gaskets. Check out Gmtnation for more info on the 360 platform and its variants. I am still quite happy with my 4,2 and do not plan on retiring it any time soon.
 

i6pwr

Thread starter
Messages
363
Location
Va
Thanks again for the good words.
Originally Posted by A_Harman
He destroked it to 3.8 liters, ported the head, raised the compression, got long duration cams, and put 3 2-barrel carbs on it. He ended up running in the 8's at 170+mph with the engine buzzing 10k rpm in the lights.
Daggone....10K is impressive for sure!
Originally Posted by bullwinkle
Looks like GM cams have a come a long way, baby! That looks unbelievably good for that many miles.
That makes me feel better. I figured they were somewhat good, but unsure if the pattern showed signs of any abnormal wear. There's definitely a lot of people here who know their stuff when it comes to oil related wear issues.... among many other areas...cheers @BrianF Thanks for that....I do try to frequent there...I agree, a ton of info.
 
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4,564
Location
Kuwait
I love this motor, and that certainly looks good to me. I've been running ACEA A3/B4 oil in it ever since I got it and already put 100,000 miles on it - truck's at 126,000 miles. I follow the OLM, although I do a simple drain/refill at the 50% mark. I'm curious, do you happen to have a picture of your PCV catch can set up? I've been contemplating doing this, but never really got around to it. There's been a mist of oil in the breather tube on top of the engine, but I don't have any issues with oil consumption.
 

i6pwr

Thread starter
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363
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Va
Originally Posted by Falcon_LS
I'm curious, do you happen to have a picture of your PCV catch can set up?
Yes I do....will include some pics. I will say this, if I could do it all over again, knowing how long these motors can go, I would have used Amsoil Sig Series the whole time along with their fuel treatment. The motor is in good shape, but the Amsoil just has a better track record. There are some small passages in this motor including the cam phaser so high quality synthetic oil at regular changes is paramount. I did use 44K regularly and has worked fantastic, but the restricted PCV system caused me some issues....but again, not the fault of the catch can, I just didn't notice the smaller filter in the lid. This is what I was using, I will likely use it again but need to get other issues fixed first. I had an angle bracket and attached the can to the bracket, then fastened to the brake booster bolt. The hose was from McMaster Carr, metal reinforced so I could get a good radius without kinking.

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JTK

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13,363
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Buffalo, NY
Wow! Looks great for the age and mileage. You kept this engine well SIr! 2002 was the first year for the 4.2 inline 6 too.
 
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4,564
Location
Kuwait
Originally Posted by i6pwr
Yes I do....will include some pics. I will say this, if I could do it all over again, knowing how long these motors can go, I would have used Amsoil Sig Series the whole time along with their fuel treatment. The motor is in good shape, but the Amsoil just has a better track record. There are some small passages in this motor including the cam phaser so high quality synthetic oil at regular changes is paramount. I did use 44K regularly and has worked fantastic, but the restricted PCV system caused me some issues....but again, not the fault of the catch can, I just didn't notice the smaller filter in the lid. This is what I was using, I will likely use it again but need to get other issues fixed first. I had an angle bracket and attached the can to the bracket, then fastened to the brake booster bolt. The hose was from McMaster Carr, metal reinforced so I could get a good radius without kinking.
Thank you very much for sharing! I'm looking to do this soon, and the pictures help greatly. thumbsup For Export, these vehicles required ACEA A3 rated oil and the OLM seems to be configured as such - it tends to go off around the 15,000 km/9,380 mile mark for me. Despite this, the previous owner was using Kendall GT-1 Synthetic Blend 10W-30, but he was also religious about changing it out every 5,000 km/3,000 miles with an ACDelco PF-61E. I follow the OLM, and have a habit of doing a simple drain and refill whenever it hits the 50% mark. When it hits 1%, it gets a new oil filter, air filter and an oil change. The throttle body also comes off at this point for cleaning. I went with MB Sheet 229.5 rated oil since I took over, starting with Kendall GT-1 5W-40 Euro, but also used Mobil 1 0W-40, Castrol Edge 0W-40 (both German and Belgian versions), and Mobil 1 Formula M 5W-40. I also used Mobil 1 5W-30 ESP, but recently switched to Petro-Canada Duron HP 15W-40 CK-4/SN, since this is what I started using across my fleet. I wasn't a fan of the ACDelco Ecore filters, which the previous owner used, and used Wix 51522XP filters until my stash ran out and Wix was bought over by Mann+Hummel. Since I have switched to a Fram UltraXG9837. While I haven't ever pulled the valve cover off, looking down the fill hole, it's clean, shiny metal. Fuel system wise, my '05 does not have a fuel filter. I believe MY04 was the last year before GM decided to do away with it. Trav hooked me up with a set of flow matched Bosch/Delphi injectors and have two sets of injectors. I do a tune up (injectors, plugs, coil boots, PCV hoses, oxygen sensors) every 50,000 km/31,250 miles and although I use Euro V spec gas, once of the issues I face is the injector on #6. Although there are no noticeable performance symptoms, the disc tends to have a noticeable amount of build up on it when compared to the others, which are clean and shiny metal. Perhaps #6 runs hotter, I do not know. I started run two bottles of Techron every 10,000 km/6,250 miles, will see if that makes any difference when I do another tune up in 50,000 km time.
 
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