Valve stem wear pattern

[Tyler J]

Just wondering what you guys think of these wear patterns. All the valves are similar to these two.

Motor is a 383, hydraulic flat tappet with roller rockers and guide plates.

Also wondering if there are any tricks to setting up guide plates correctly so the roller tip is centered on the valve stem. There are a few that were off centered.

*Side note, I'm hoping this is just the assembly grease in the oil? I Did the break in, changed the oil, then ran the motor for another 30 mins or so.

 

[ldr]

I'm not a engine builder by trade, but the rocker looks pretty good where its sitting on the valve. T&D recommends their rocker sit .025 past center so it will roll to the middle when the valve is open. They claim this helps guide wear. Just my 2 cents.

 

[vanrah]

Greetings TylerJ & all; Maybe I can help, I had the same problem. Wrote a letter to Comp Cams & the VP ( Mr Sparkes) called me! We spoke 6 times for about 4 hours, not kidding. We were similar age & had some similar (we both had L-78 Rats) experiences growing up. Anyway he educated me about the latest cam, valve train & oil tech 2013. I can't say Enough Good about him & that company, Comp Cams. What you have is loading a rate that is high enough to start the surface of the stem tip to start breaking down. You may notice that the rollers on your arms are starting to dis color? I also had this symptom. The fix is, first the oil (do NOT use street oil in hot rod.) something with a good dose of ZDDP. Second the load has to be spread out over an larger area, lash caps will accomplish this task. They are Harder then valve stem tips & ten to float a smitch correcting any minute angle mismatch between roller & stem tip. This wear pattern also indicates possible valve train harmonics that are above the tolerance of the materials interfacing. He sent me a hi-speed video of a SB Chevy 3/8" studded rocker at 7000 RPM. I now have 7/16" studs & new rockers. If you have the Ultra's I think you can send them in & have new bearings, pivot shafts & rollers installed? And last check your valve springs, make sure that they match your cam, are installed at the correct hight & still have the seat pressure that's required for your cam? Somewhere between 10% -15% under spec makes them ready for the recycle bucket! Hope I helped, Ol'e Bob.

 

[64nailhead]

Being centered on the valve stems is unimportant. What is important is to make sure that the entire roller is contacting the valve and that the wear pattern is as narrow as possible - somewhere between .060"-.070".