wr1970

Did oldsmobile send motors out with cranks that had been turned? I tore down a 455 had one gm rod and the rest were xc. The rods had no numbers and the crank was 0/10 in very large letters. This engine looked like it had never been apart.The rods were .010 mains were standard size. The gm rod was dark steel the xc rods were gold tinted metal!

rob1960

I looked through the '70 engine section of the service manual & while they do show the factory using things like .010" o/s lifters(try to find a set of those today!!) & valves with .010" o/s stems being used,the section on cranks makes no mention of using cranks with undersized journals. All they show are special small increment 1/2 thou or so oversize bearings to obtain correct bearing clearances. The parts books do list o/s bearings up to .020"

Magna86

Post some pics.

wr1970

Of what a empty block the crank or the rods and piston This is basic stuff i was just wondering if any motors went out the door with a 0 mains and .010 Rods.

BlackGold

The 1970 Engine Assembly Manual shows that crank bearings were hand-selected for each position based on both the block/cap bore and crank diameter.

The manual also shows that pistons were hand-selected for each position based on cylinder bore. Actually, the pistons were already assembled with the rod and pin as a shop assembly. No selection was made for the rod bearings with respect to the rods or crank.

There is no mention anywhere in the manual about .010" undersize when it comes to the crank. There is mention of .010" oversize lifters to be used as needed with oversize lifter bores.

wr1970

Okay i was sure not done at any machine shop because no numbers on the rods.There is now because i always stamp them when i tear a motor apart.Thanks for reply's.

cherokeepeople

back in the late 80's i had a 74 455 that ran good.pulled it out of the 98 to use in a 67 toro.pulled the pan and checked the bearings.checked the center main and it was standard.so just got a set of standard bearings and buttoned it up and put it in.got it running and had about 10 lbs of oil pressure thought wth.so pulled it out and pulled the crank and remic'ed all the mains.turns out the one i checked was the only standard one of the bunch had 2 .005 under,2 .010 under and the one standard.went to the local olds dealer and got the bearings to work and afterwards had 50-60 lbs.

66 POST

I've had hundreds of Oldsmobile motors apart and had only one with a .010 lifter . While working at Stohlman Olds around 1978 the shop foreman pulled what I thought was a new diesel into my stall right off the truck. Opened the hood and it was a 403 . It had a .010 overbore and standard pistons.