sorry, forgot it was a public forum bad to post email addy

https://1drv.ms/x/s!AjoXnVa96mPNmJJClN-u5oCid3B_ig

I believe another poll regarding CRD engine timing belts, rocker arms, and ARP stud upgrades would be redundant and might likely muddy the waters even more than they already are.

I think the narrative on these issues is going the wrong way, as a lot of the discussion regarding valve failures, rocker arm failures and head gasket failures so far has been little more than speculation. Comments like "cheaper by the truckload" torque-to-yield head studs and other complaints regarding both the rocker arms and the valves are indicative that the decision regarding the culprit or culprits for the seemingly over-abundance of head gasket failures and valve train component failures has already been made.

That said, some testing of the valves by a forum member or an associate of a forum member was supposed to have been conducted, but I do not think the results of such testing has been posted as of yet. Perhaps there is no adequate test available to determine exactly why engine valves fail, and that is why nothing has been posted.

Perhaps a better way to go about finding answers would be to have a couple of CRD forum members directly communicate with the actual engineers who designed the R428 engine, and ask them the appropriate questions as to why there seems to be so many problems with the cylinder head and the valve train of the R428 engine. Why were torque-to-yield head bolts used, why are the rocker arms and the valves apparently so weak that they fail often?

I do not believe anyone has tried to contact the V.M. Motori engineers regarding these issues. If I am wrong, and indeed a CRD forum member has contacted the engineers who designed the R428 engine, please post a synopsis of those communications for the benefit of all CRD owners.

I added a column for cooling mod(s). Maybe that info should be organized better? I think the cooling mod that might be telling would be the inline T-stat. I think there were some overheating problems with a few members that put an inline in their upper radiator hose.

Replaced Timing Belt at )cough...cough) 120,000. Nothing else done.

Jim Hulse swung by Texas and we did the whole kaboodle at 192,000 miles...timing belt, water pump, valves and rockers. All valves and rocker were still in good condition. Have had EGR Stealth...then GDE...then Weeks I and II. Probably all helped keeps valves and rockers good.

Pardon my ignorance, but considering new exhaust valves for my liberty and currently ordering parts for my mechanic, I assume their are 8 valves, should I order new seats/springs for those as well? Im also ordering the rocker kit..

they were able to grind my existing seats and we reused the existing springs. you should get the guide seals too (machinist said to change them and they're not very expensive). i changed all of the valves and glad i did. some of the guides and seats were not exactly aligned. could have been defective and like that from new, or maybe the casting distorted from heat and pressure or bad head bolt torques or maybe all of these.

This engine has hydraulic lifters and the springs are very strong, so I don't think it would need shims... but that is a lot more than most people think about. I think the shims would be more important on mechanical lifters rather than this design.

Considering that the springs are compressed more than 3/8" from zero pressure and that even if you somehow installed the seats all the way up in their wells... you still wouldn't have reduced the springs to an uncompressed state.
I do not believe that shims on the springs would be needed in this design if the valve position was altered by grounding. If anything, the preliminary results of the testing suggests that the springs may be too strong if the valves are failing because of cycling fatigue.