journal sizes

[amcinstaller]

anyone know what size the main and rod journals are on a bone stock crank (no over or undersize)? got my crank in front of me and i would like to see what im looking at for journal sizes of this one vs stock.

[Sharp Rock]

From my 1995 Factory Service Manual. This would be the same for all years of the 4.0, and the 258 as well, since it uses the same "basic" bearings. But not the same because of block differences.

Main Journals 1-6 are 63.489 to 63.502mm
or 2.4996 to 2.5001 in.
Main Journal 7 is 63.449 to 63.487mm
or 2.4980 to 2.4995 in.

Rod Journals are 53.17 to 53.23mm
or 2.0934 to 2.0955

When my I had my crank reground (12 counter weight) my machinist pointed to some marks made on one of the counter weights. He said, "count the marks, that will be the number of cuts made on the crank". A year and a half later, I don't remember what they looked like, but they were obvious once I looked for them. Mine had 3 cuts. However, always better to measure, as you are doing. The mains and the rods may not always be the same number of cuts.

Jerry

[Alex22]

Also, a lot of shops will just stamp R## M## on the crank to show that it has been ground.

[amcinstaller]

i suppose i maybe should have mentioned, i have an 80, 12 cwt crank. i guess it doesnt matter though. my machinist wrote 10-20-10 on my work order, but im not sure what the numbers mean. im guessing that they mean parts are undersized .010, and another spot .020 undersize, but im not sure which is which. ill measure them in the next day or two and see how i compare to those numbers though, thanks.

ps- no markings made on my crank.

[IH 392]

If the shop is component they give you your crank back marked like this.

[amcinstaller]

just written on the work order. it hasnt been polished yet, only ground, so that may have been included in the polishing