Hello variablevalvessuck
I too am a qualified tool maker for the aviation industry so I know exactly how engines and machinery are manufactured and I fully understand that precision grinding tools will eventually wear to the point that tolerances will be compromised but this will be after many units have been made, the dimensions will be either measured or checked with a go/no go gauge and adjustments made accordingly.
My point is that if the original poster wants to fit new big end bearing shells to his crankshaft then surely he will have to get it re ground, but apparently you cant re grind NC cranks and as it surely is not advisable to to fit new shells to a worn crankshaft then the only option is to source another crankshaft as I originally stated rather than waste time and money trying to get the exact size bearings.

tevie54 wrote:Hello variablevalvessuck
I too am a qualified tool maker for the aviation industry so I know exactly how engines and machinery are manufactured and I fully understand that precision grinding tools will eventually wear to the point that tolerances will be compromised but this will be after many units have been made, the dimensions will be either measured or checked with a go/no go gauge and adjustments made accordingly.
My point is that if the original poster wants to fit new big end bearing shells to his crankshaft then surely he will have to get it re ground, but apparently you cant re grind NC cranks and as it surely is not advisable to to fit new shells to a worn crankshaft then the only option is to source another crankshaft as I originally stated rather than waste time and money trying to get the exact size bearings.

You seem to think there are only two categories of parts in the Honda (or any other, for that matter) production line; inside tolerances and not inside tolerances.

As many have been trying to tell you, this is NOT the case. Finished parts found to be within tolerances are (oftentimes automatically in the grinding machine itself. Marposs anyone?) measured and labelled/coded according to their dimensions.

If you think all produced parts are the same size, you are blatantly ignorant. In fact, NO two parts are the same, only variations within tolerances.

If you cannot understand this, there is nothing more we can do about it.

Good luck in your future engine building adventures

Lasse

I'm sure Mr Honda would be very impressed if his precision grinding department couldn't produce two crankshafts with the same bearing journal diameter haha.

You Sir, are indeed a moron. Only God himself may be able to do what you seem to believe to be common in industrial production lines.

I did the main and big end bearings in my FZR engine.
The original ones were not all the same size / colour code.
The ones I fitted were not all the same size / colour code or even the same as the old ones.
I used plastigage to get the correct size shells.
It's called production tolerances.
Every engine is like that, even Honda ones.
If you asked Tony Scott why he " blue prints" his V4 motors. It's to
reduce production tolerances.

L.Svedberg wrote:You Sir, are indeed a moron. Only God himself may be able to do what you seem to believe to be common in industrial production lines.

Funniest thread in months. You read some shite on the internet at times, but some of his (tevie54) posts are priceless. Almost on a par with xivlia for idiotness. Almost.

Malc wrote:

L.Svedberg wrote:You Sir, are indeed a moron. Only God himself may be able to do what you seem to believe to be common in industrial production lines.

Funniest thread in months. You read some shite on the internet at times, but some of his (tevie54) posts are priceless. Almost on a par with xivlia for idiotness. Almost.

agree

WHY doesn't this forum have a "like" or "thumbs up" button!?

L.Svedberg wrote:You Sir, are indeed a moron. Only God himself may be able to do what you seem to believe to be common in industrial production lines.

That's why i gave up on this thread nearly a week ago.

vfrman wrote:WHY doesn't this forum have a "like" or "thumbs up" button!?

Seems you have got some work to do