Anyone ever seen this?

[BHPSteel]

This thread is better than a Russian novel.

Dunno about *better*. Longer, maybe.

 

[mikey357]

Ouch... Kicked in the feels again...

All this talk about "Tolerance", and here we are, STILL assailing each other's feelings...

 

[Dan Muk]

This is exactly what tolerance stacking is and can go wrong in an engine. If a crankshaft is growned and Polished and each Journal is at a different spec. When you install the crankshaft bearings and the tolerances are as you say all over the map this can be disastrous to an engine. It can lead to low oil pressure If close attention is not paid to the specs on the crankshaft when machined. That's why when I install a crankshaft I use a dial indicator and measure each Journal before the installation process begins. If the crankshaft range is erratic then I have it redone to a closer spec.Then measure the Journals again and average the measurements. I also install the bearings after torqueing the caps without the crankshaft and then using inside micrometer to measure the spec of each each Journal bearing and rod bearing. Then I Average the measurements all out together and find the middle of the road of all the measurements. Then I rearrange bearing halves until I get all the bearings as close to that average measurement as possible. If this is not done that's what leads to low oil pressure and that is tolerance stacking when you just throw everything together and don't use a micrometer or dial indicator on each measurement and pay close attention to what bearing goes to what main Journal or Rod Journal. Some journals at high end and some at low end equals low oil pressure on a HP engine. Same can be seen with installation of piston rings in a high HP application of nitrous.

Lotsa trouble if you ask me.. Plastigauge that bitch and hit the bricks!

 

[Psilloh1]

All this talk about "Tolerance", and here we are, STILL assailing each other's feelings...

Really? This is the one..? This is the post that pushed it over the top?
GTFO….