machine crank or rods?

[dave186]

im helping my boss set up a motor for one of his trucks. its a fairly mild 460 for towing. not towing like campers and stuff, he always has a backhoe or tractor or something hooked up to this thing. so on to the point, he got some H beam rods that are some sort of chineese brand or something but i forget the name off hand. the crank is cut .10/.10 and we went to slap it together and have very very little clearance on the rod bearings, .001 (or less) on the bottom and about the same on the sides. these are brand new rods so i dont know what is going on here, but its wayyyyy to tight. what do you guys recomend?

[Oldsquirt]

Have the journals of the crank re-checked.
More importantly have those rods thoroughly inspected, big end, small end, weight. You name it, it needs checking. There's a reason those things are cheap....errr, I mean inexpensive. :)

[LakesOnly]

Dave,
Just because the rods are brand new does not mean that they are within spec. As noted above, check every machined dimension on the rods and all mating parts.
LO

[dave186]

thats what i was afraid you guys would say. i have a t gauge but no micrometer that big, so off to the machine shop i guess. at least this time its not my money, just my time.

[Moneypitt]

You didn't mention the bearing size or brand........The crank is 10-10, what are the bearings? Did they come with the crank? Also, you should be able to get a good idea about the crank with dial calipers, what you're getting for clearance, (how are you measuring clearance??) says the crank is too big, an error that should show with calipers, if that is the case. Measuring the inside of the torqued rods accurately is a little tougher, but if the crank shows big with calipers, then its off to the grinder/polisher, and the rods are probably OK........MP

[dave186]

the bearings are clevite 77, and they came from the machine shop that did the crank, yes they are .10 as well. im measuring clearance with plastigauge. we have some nice digital calipers at work, i will steal them and see what i come up with.