I have recently completely rebuilt my '97 12 valve. Everything was machined to spec. Ring caps were perfect on all cylinders. Installed stage three cold cam, BD super bee turbo, 3200 rpm goveneror spring installed. Cylinder head completely rebuilt-new guides, new valves, new seals, engine has about 5000 miles on it. Engine was on dyno for break in ... now I have oil showing up at all exhaust ports on manifold. Checked valve seals, everything looks good. Any Ideas why this is happening?????? This is the second engine I've rebuilt and the second time this is happening. Used felpro gaskets and seals...never had a problem with them before. When truck is warm and idles for about 5-10 minutes...when you rev it up - you get a puff of blue smoke.You can smell that it is oil. Very little blow by as engine is new.Manifold looks like a cold running engine in winter time. Could this be from all the modifications? Also , have AFE arcflow elbow and 5" mbrp exhaust.

 

valve guides or shot

 

Maybe Its not all the way broke in. make sure your fluids are ok and hook it up to a trailer and work the engine. There ment to be worked and it might need a good workout to finish breaking it in. idk. maybe im just blowin smoke but thats what i would do. Just keep a good eye on your engine vitals. good luck

 

I have been there on an almost identical build. At first it was the valve seals. So we pulled it apart and put a different style valve seal on it and it still did it. I think it was just from not being broke in all the way.

 

Thanks for the info. I did a little more research and found some of my valve seals had lifted off the stems and found out from other sources in performance engines that with a stage three cam and high rpm and high cylinder pressures this will happen. I was told that in real high hp engines like those in sled pulling and dragracing they normally don't use valve seals on their cylinder heads for that reason. I'm going to try heavier valve springs and hopefully we don't valve float. Also found out you can run what they call a tophat valve seal that the spring holds down in place. They say they are in the newer engines but can be used in the 12 valves but the posts where the seal clips on must be machined. Hopefully this helps someone else out there that is building some hp out of a 5.9l