is machining needed or can i get by without .

[COOCHaDAMus]

i'm kinda light in the pockets can't do a full rebuild. my question is can simple ring & bearing replace go without machining the block, crank, cam.? oh car is 1980 210 with 280.XXX on the bottom end. heads have already been done over.

[bonvo]

it depends on the condition of the block but at the very least the block needs to be honed you can buy a ball hone for about 50 bucks 

[Draker]

You can rent a ball hone from a parts store. But yeah, hone. Remove ring ridge.

[datzenmike]

 

 

Run your fingernail over the ridge. If it catches it should be lightly and carefully reamed to remove it. Preferably before forcing the pistons out from below. If they are out, it should be removed so the new rings don't hit it on the up swing when running.

 

Yes you can hone and ring any old motor but the results are directly related to how worn the cylinders are now. Honing will not correct taper or oval-ing of a worn cylinder nor will it remove the ridge. If you have a ridge that catches your nail it should be bored.

 

I did my old 521's L16 for about $100 back in the 70s. It was very worn and with a ridge that I left alone. Added new valve seals, rings, rod and main bearings allowed it to run for another year or two. A big mistake I made was running chrome rings. Never on a quick hone only on perfectly round straight re-bored cylinders. Chrome rings are too hard to seal an old bore. Get cheaper cast iron rings that seat and wear in faster.

[ggzilla]

An engine overhaul means new rings & bearings, but no machining. Rings only need honing.

 

A-series blocks rarely need machining. Camshaft bearings  never need replacement and Nissan does not recommend replacing them.

[DAT510]

Check head and block straightness, if they check out you're good for machining. All you'd need at that point is a hone and re ringing. You could even get away with using the same bearings, but with 280k miles id replace them.

 

If the head has been done over by  machine shop or something its likely they already checked for head straightness. 

get a micrometer and check the diameter of the cylinders, make sure they are round and not oblong. If they are the latter, a simple hone wont do. 
Rarely do you ever need to machine a crank. Maybe polish the journals.

[Dawa]

the machine shop SHOULD be able to mic EVERYTHING for free, if theyre nice.

and with that information, you can decide how cheap (but efficient enough) you can go

[COOCHaDAMus]

kool my fellow datsunites, honing is something i can do thanks ya'll.