DL: LOL it's no secret and I'm happy to outline how I build but it goes against the "conventional wisdom" in many ways and while it works for me MANY will disagree! ;)
Really depends on your block if it's going to work out within spec (this is why the give you plastigauge in the kit so you can check but if it's NOT in spec what do you do?)
A shop will fit the bearings to the block measure it then grind the crank to suit so you can use ALL the same size...
There's enough room to get a direct reading off the bucket but you need an extended probe on the indicator to do it.
I use a magnetic base and a piece of 3mmx50mm flat that bolts onto the Cam Cover bolt holes.
"Valve Lift" is generic in nature and refers to the Valve coming off the seat...
Plastigauge is a rough and ready way to check the final Oil Clearence NOT a substitute for precision measurements.....
Our motors use a select fit bearing system from new, on the production line the measure everything then stamp the block with a series of numbers to indicate bore and main...
I indicate off the back of the bucket so 50 thou valve but I can't see that there's any difference as we don't have a rocker arm or anything that changes the ratio from Cam to Valve..
The idea of the 50 thou is to get the cams off the base circle and to remove the ramps so you get a consistant reading without having to add/subtract anything ;) (cams can have very different ramps and this will affect the reading and this is how/why you can have 2 "272" cams that are quite...
As we've discussed I have some very specific ideas on this subject that come from a lot of "testing to destruction" after following the conventional wisdom on 7M rebuilds and seeing multiple failures.
Maybe it's just my particular driving style and car use that's the cause but how I now build...
I'm "special" ;)
I broke a Ferrea......
In my case I think it was a tight shimless bucket in combination of holding it above 8000 for prolonged periods that killed it.
I had to discard 3 other springs that had lost 10 psi seat pressure, since having them Cryo treated and the buckets...
Greg: LOL correct (been a long time since I've played with a stock head)
Just went out and popped a valve out of a junk head to check (not that I didn't believe you ;) )
2nd pic left bearing is the start of fatigue/delamination
The backs of the bearings look like the rods have a very rough surface finish in the bores so they're not getting full contact and are moving around.
Either that or the rods are undersize so again the shell doesn't make full contact...
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