stock pistons...

[Shark]

so it seems from the information you guys have gathered that the 91-98 pistons have the greatest amount of material to be removed. how will we figure out what the most safe dish limit is?

[Flash]

so it seems from the information you guys have gathered that the 91-98 pistons have the greatest amount of material to be removed. how will we figure out what the most safe dish limit is?

We can assume that the extra weight is from a thicker deck...............but it could be from a thicker skirt or wrist pin also. thats why we need some numbers on these pistons first.

That is a good question tho...........we know how much KB recommends for a minimum on there pistons.............But ............................


Flash.

[Shark]

so it seems from the information you guys have gathered that the 91-98 pistons have the greatest amount of material to be removed. how will we figure out what the most safe dish limit is?

we know how much KB recommends for a minimum on there pistons.............But ............................

is there recommendation a minimum for cast pistons or all pistons? even if it is just a minimum for cast, could there also be a difference in cast quality? i mean can there be a difference in the strength of one manufacturers casting compared to another given a constant thickness? or is there a standard? make sense?

[John]

"is there recommendation a minimum for cast pistons or all pistons? even if it is just a minimum for cast, could there also be a difference in cast quality? i mean can there be a difference in the strength of one manufacturers casting compared to another given a constant thickness? or is there a standard? make sense?"

Too much variance in casting alloys to disregard the strength differences between mfg.s.
John

[gradon]

It'd be interesting to see how much stronger a hyperteutic(cast w/ silicon) is vs standard cast vs forged. KB/Silvolite vs Federal Mogul.

[John]

Sure would, but they are reluctant to share their particular casting procedures.
John

[SilverXJ]

I have a 2000 stock piston that I can hack apart, but it will be a while before I get to it. I actually have 4 in varying degrees of damage. Mostly damage to the skirts (I forgot to release the caps on my damaged 2000 engine before releasing the crank... crank cam out, pulled pistons down and locked in bottom by rings..oops). If anyone wants one pay shipping and I can have them in my hands to ship in two weeks to ship.

[John]

Got back to our stock piston information.

We have at least three groups of OEM pistons in the 4.0 blocks.
Renix-------510_ 514 grams less pin
91 _98------563_567 grams less pin, .128" depth D shaped dish, of 14CC size, floor thickness is .3" in the very center.
99 _ 04k--- 417_ 429 grams less pin

The 1993 piston thickens quickly from a machine centering depression inside the cavity. You could create a crown top inside the existing dish, just stay outside the very center and there is room to enlarge. I still have the top of the slug, so if anyone wants other measurements, let me know. The piston was of good grain structure and seems a quality casting.
John