Ls1 cam bearings mods#

Ls1 cam bearings mods#

We inspect the cam bores for size and alignment, and cam straightness on every LS we do, we are looking at and experimenting with oiling mods to the cam bearings and block. Cams used in failed motors range from stone stock, to every common reliable manufacturer we have ever used. I have seen about fifteen LS motors in the last few years with cam bearing issues. In the past prior to the LS motors, I have only seen two or three motors with cam bearing issues in 40 years.

Most LS engines we see have much more cam bearing wear than expected for the mileage run. The LSX blocks are supplied with the cheaper bearings, but we toss them out, we have an LSX in here right now that ran for a short time with those rolled bearings and needs the block repaired. The one piece tubing style are much better, as they have more 'crush' and no ends to scrape oil from the bearing, but we have seen failures in them also. Do not use the cheap 'rolled' bearings, these are rolled from flat stock and have an interlocking part on the ends. Other blocks will simply 'walk' the bearing out of its bore until it contacts a cam lobe, the side of the lobe shaves metal into the oil until it catches the bearing hard enough to pull it out. The cam bearings will weld themselves to the cam and spin, requiring an oversize bearing to be installed after the block is bored for it. Failures are found with completely stock engines, and with rebuilt Hi-Po units also. We have been seeing cam bearing failures at an alarming rate with these engines, not with just the aluminum blocks, but the iron truck blocks and even the LSX blocks. Here's the one post that really worries me: Trying to educate myself before having another motor built. I'm looking for knowledge on the issue, and whether anyone has solved the problems I've read about. But, now I'm scared shitless about this happening again. I'm committed to an LS turbo due to all the fabrication labour and cost is already done/spent. My first build goes horribly, and expensively wrong. Now I see hundreds of LS builds making great power. I've read posts from engine builders with 40 years experience that, as of yet, haven't been able to pin the issue down. I had my doubts, but now I am reading that these LS motors do have issues with cam bearings. He says he had no issues with the bearing install, and the cam went in fine and spun freely. It did fire right back up after this incident, but the very next time heat was put in the motor, the block grabbed the bearing that was now welded to the cam, and stopped it dead, breaking the timing change, and making a mess of the valves. The motor came to a screeching halt within about 5 minutes of first firing.

He installed new coated cam bearings and a new Lil Johns stg 2 turbo cam. He noticed cam bearing wear that was severe, especially considering it was a 20,000 mile motor. This was a low mileage LM7 cast block truck motor that an engine builder went through. I lost a freshly built LS turbo motor in about 5 minutes.