Renewing my cylinder head

[RobE30]

A few years ago, I rebuilt the bottom end of my m20 after hitting a rock w/ the oil pain. I had the head checked over @ a machine shop and it got a clean bill of health. It's about time to do my timing belt and with just about 200k on the stock valvetrain, I figured it'd be good to install some new hardware up top. When I rebuilt the bottom end, I also installed a Schrick 284/272 cam and have been running that combo for about 20k without issue.

I plan on replacing the rocker arms, rocker arm hardware, eccentrics and valve springs etc. I'd like to go with IE HD rocker arms, OE valve springs and regular eccentrics. Should I replace the rocker shaft as well? Anything else I should do while I'm in there?

[MR 325]

Really no need to replace the rocker shafts is they're in good shape.

Sounds like you've got the right idea to me!

[jeffnhiscars]

Since the goal here is to freshen the head so it plays well (Nd for many miles) with your reasonably fresh block, you really ought to do the valve guides as well. My barn find had a broken timing belt when I bought it so even though the head was scrap there was noticeably more wear in the exhaust guides than the intakes...and that was a 98k engine.

I see lots of posts about cams etc but not nearly enough talk about valve guides. They matter

[jlevie]

A head for a race engine (a more demanding use) gets new valve guides and exhaust valves. Intake valves only get replaced if worn. Rockers only get replaced if they show wear, but they do get polished and dye penetrant checked in the area of the eccentrics. Each spring is tested and replace any weak ones replaced. Rocker shafts only need to be replaced if worn. The cam is checked with a Cam Doctor scan and blue printed or replaced as indicated.

[RobE30]

I forgot about the valve guides.... I wonder if it'd be worth it, from a cost point of view, to have the new guides pressed in, buy all the new parts or just buy a higher flow head from BimmerHeads?

After reading Jim's post, guess I should go over everything thoroughly before I put out too much $$