Hey, Im having trouble with my build hoping I can get some insight. I got my block back from the machine shop after being bored/line honed etc. The #1 journal was measuring in at .0035 ish with plastigage. I ordered new bearings .001 undersize and it was no different. Then I decided to actually measure the bore size for out of round etc. Turns out #1 measured (with no bearing) 2.6437 top to bottom and 2.6406 (measured 3 oclock to 9). Thats basically .003 out of round. The machinist said it would be fine and to run it but that he would re hone that one if I want. He said as long as its out of round top to bottom its ok. I need some advise on this. Thanks!

The other bores are better with between .001 and less out of round.

 

So I put in the bearing and now it seems to be more round. not sure whats going on here...

 

When a block is align bored, the caps are ground a few thou and then torqued in place. Then a long honing bar is run through all 5 main bores at the same time. Unless the block has warped in some way over time, no, or very little material should be removed from the sides of the bores (3 to 9 o'clock). From your numbers you are .0031" out of round. To me, this is unacceptable and is definitely going to affect the bearing crush. In other words, chances are really good for a spun bearing. This cannot be corrected by just honing the 1 bore. Plastigage is not a measuring tool, only an indicator. Did you measure with a dial bore gauge, or a caliper?

 

Well I can say that these caps have not been ground down. Dont have a nice machined bottom to them. I was using a bar guage (or whatever they are called) with a micrometer. I just checked with my calipers and (with the bearing) i am getting roughly 2.453 top to bottom and 2.4525 side to side. The crank journal is 2.4485. I guess its within spec at this point as far as being round. Im thinking I was using my 1st set of instruments badly. Caliper shows a different story. Now on to the bearing being too large, This means I am getting .0045 clearance. No wonder the plastiguage was barely squishing. I guess I should be at 2.451 to be at a oil clearance of .0025.... Should I use .002 oversize bearing? I dont even know if that exists.... I know they are mostly undersize..

 

Like to see .001" clearance per 1 inch of diameter, you're almost double that. I'd really look close at the parting line surfaces on the block and cap, make certain you have a clean metal to metal seating. There are .002 OS bearings but hard to find - that I've seen.

 

I have checked everything I can multiple times. Engine is super clean. Im going to take it back to the machine shop that did the work. Seems like it should be on them to make it right considering I paid for a line bore and bearings 1+2 are not in spec. They should have called me and told me they were going .010 over or something like that.
I have searchd for .002 oversize bearings and cant find any for SBC.

 

Bearing size is dependent on the finished size of the crank. If they only align honed the block, they might not have cut the caps. It needs to be align bored now... then you need to check your timing chain tension as you might need a special set that compensates for the amount of material taken off the block.

 

Were the caps torqued when measurements were taken?