Last time i Had a full rebuild done and upgraded my cam to a 224/228 .581 .588 110lsa with a 3800 circle D stall. Only about 1700 miles on it since all that was done and it started making a loud knocking noise about 3000+ rpms under normal driving, and on the highway with cruise on about 60 the oil pressure would fluctuate from about 25-45 psi. And ideas? And Yes there was metal shavings in the oil. She shop said it was under warranty. I took it to them and they started tearing it down. They are a very reputable shop in this area. At first they blamed it on detonation. I think they have ruled that out after going over there and speaking to them. They said they were going to tear the rest of the motor down, heads, cam, pistons ect. It seems they are looking for anything thats not their fault so they don't have to eat the price of the rebuild. The original build had brand new everything, bearings, lifters, oil pump. Any Ideas on what could cause this? Bad oiling?(oil pressure was good until the pinging started about 1650 miles) Trash from the spun cam bearing that happend before I took it for a rebuild?

Here are some pics

Spend a few hours doing this



Lower Rod bearing on cylinder 1


Upper rod bearing on cylinder 1


Another one that is starting to show some signs of wear


4 or 5 of the bearings looked like the 2nd picture, the rest of them looked to be ok.

Thanks and look forward to y'alls input.

 

sounds like bad machine work or incorrect clearances (redundant lol). i dont even understand how they can say that detonation would spin your bearings.

 

Thats what they originally said but since have changed their mind to trying to find something else that would have cause it.

 

Little easier to see them on the laptop than on my cell phone. I still say dirty build and bad job putting it together seeing how all the copper is showing. No way it should be like that with less than 2K on the motor.

 

Im with the other guys, improper assembly, dirt, improper torque specs, improper bearing clearance. Dirt wil leave the groves as in pic 3, I would bet there was improper torque specs or clearance between the bearings and journals.

 

Do you know why the cam bearing spun in the first place? Maybe bad oil flow due to the bearing being installed improperly. Could be bad clearance for the bearings. I would guess it was a problem with the clearances in the rods or mains before anything else.

 

No. Don't know why the cam bearing messed up in the first place. Cody (1slow01z71) seems to know my motor better than anyone. He's been there for everything we've done.

 

About 4 years ago I installed a cam in his truck, and ran great for what 30-40K? As far as I know there werent any signs of oil pressure problems. He wanted a bigger cam and I had one so I sold it to him and helped him install it. When I went to pull the cam, it wouldnt come out. I finally was able to get two journals out and it was stuck. Daniel said screw it and told me to go ahead and yank it out. I got it out and the center journal was BLACK, obviously had some oiling issues. No idea what caused it, I installed it like every other cam Ive ever done but obviously something wasnt right whether the cam blank was bad or the bearing was knicked. I tend to subscribe to a bad cam blank as a couple of the lobes were eaten up and after further research it was from about the time Comp sent out all those bad cam blanks.

The way the bearings are worn, either the journals were out of alignment or wrong size bearings were used(improper oil tolerance) and like Rhino said the scratches show a dirty build also.

With this build I had nothing to do with, I wish I wouldve had time to build the shortblock for Daniel but I just didnt have the time when he needed it done by

Daniel if you get a chance post up those pics of the cam. Once you get the motor lined out we'll get the tune running good, Im interested to see how your truck runs compared to mine once theyre both running good.

 

I've got pics of the old cam on my computer at work. I'll post them tomorrow. And there was no oil pressure problem except once before it fluctuated and I put a new oil pump on and it fixed it and it ran fine for another 15k miles or so. Then we went to put the bigger cam on and well it all went to hell.

 

Cody here are the pics from the old cam. This is the 216/220 that I ran for seemed like 3 years.