Valve work

Lassie · Dec 5, 2012

Was just curious about what valve work you guys that are studded got done on your heads when they were off. It looks like in most threads, the heads were cleaned, fluxed and decked and slapped back on.

Do these heads rarely need valve seats and valve grinds? Are the valves typically really clean? Any valve guides wear? Springs?

What do the valves and train typically look like at 100K miles? 200K?

Cr500 · Dec 7, 2012

I have been working on these engines since they came out, have repaired too many to count. But when it comes to head issues, 3 things are always constant regardless of anything else. Valve seat wear, guide wear, deck warpage. On a stock engine, the blow by mixed with the soot builds up and eats at the seat. Once the seat wears then the guide and or stem wears. There is a correct number clearances wise for the valve to piston. The people that simply mill a head flat and don't recess valve x amount are asking for it.
The oem valve guide seals are crazy tight on these, so I was thinking for a while that was part of stem/ guide issue. I started using a different brand for seals and are set up tad loose now.
On average I'd say if it has over 50k there will be some issues. If you did a leak down before tear down you would find leakage all over the intake valves. Out of 16 intakes I'm usually trashing 4 or 5 valves due to problems.

Mdub707 · Dec 9, 2012

When I brought my heads in, they were cleaned, pressure checked, magnafluxed, decked, and had a valve job done. I also had all new valve seals put in.

04stroker · Dec 9, 2012

I rarely see any valve seals work very bad in these. But we have to do a lot of valve refacing and seat grinding as well. Plus the valves should always be recessed anyway when the heads are milled.