If you are taking apart a 4.3L engine, getting it cleaned, honed (still same diameter), crank turned, new cam, new roller rockers, do you need to keep the pistons etc, and push rods ordered or will it matter?

thanks

i do for all motors (it cant hurt to anyways)

it isn't really ever necessary to keep the pushrods in order. Some people say to, but I don't know any auto tech, including myself, that do. And have never had a problem. The pistons if being honed can go back anywhere. Since you are replacing the bearings and having the crank turned the rods can go back anywhere as well.

that is what I thought.. I am having a beast of a time getting this thing back together. I am just at the #1 piston.. I got it in fine..got the rod down to the crank and put the cap on (with the bearings), but after I put the cap on I cannot spin the crank to get the crank ready for #2..it feels like it is bound. It is driving me crazy.

it isn't really ever necessary to keep the pushrods in order. Some people say to, but I don't know any auto tech, including myself, that do. And have never had a problem. The pistons if being honed can go back anywhere. Since you are replacing the bearings and having the crank turned the rods can go back anywhere as well.

it dont exactly apply here but on some other engines the pushrods are different sizes. my buddys dad was rebuilding his late 90s malibu engine and put the rods in wherever and crewed up a bunch of rocker arms. so for some engines might be a good idea to keep them in order

turn the rod cap around

I tried that. I was going to take the piston out, but I am too scared to do that. Plus, the piston will move in the cylinder, but I think the bearing are the problem. I will have to check them tomorrow

One side of the rod bearing will be chamfered, and needs to face the outside of the rod journal.

topless is right.. but theres more.

did you even check to see if the rings needed to be filed?

check the ring end gap.

to do this.... boy, if you dont know how to do this, take the engine back to the machine shop.

if you think you can do this... well, listen up.

put a piston ring (*the top one first, on #1 piston) into the bore. push it down one inch all the way around. use a piston, its easier.

take a feeler guage, and see if you can get a .018 feeler guage minimum in between the ends of the ring. *(im presuming that you arent going to run nitrous here)

If it wont fit, remove the ring and file the end of the ring till it does. reinsert/remove/file until you get the gap right. move to the next ring, and repeat. this applies to the top rings in the engine. the oil rings probably have enough clearance. check them as well to make sure.they can have less clearance, but you dont want the rings to butt up against each other.

a rule of thumb is to use .0045 gap between the ends of the ring PER INCH of bore if you DONT use nitrous. if you use nitrous, the gap goes up to .005 per INCH of bore.

Theories vary on the installation of rings. My way may not work for every engine builder.

your mileage may vary.

another reason to use a piston is it helps keep the ring square to the bore when checking the ring end gap. which is important.

did you even check to see if the rings needed to be filed?


Would that really be the problem? He said the piston moves fine in the cylinder when the rod isn't attached to the crank. So how would the pressure created by the rings change when he bolts the rod "to" the crank? I'm not trying to correct you, but I can't seem to understand this so I'm hoping to learn. :D

I am beginning to think that the bearings might be the wrong size.

Did you plastiguage them?

You do realize that you have to mark the caps of the rods & main caps before disasembly. They are machined together as a set so you can't swap caps or flip caps the opposite direction.

Each time you put a rod on the crank it should increse the turning resistance a certain amount. You should have the numbers and be checking this as you go.

If you didn't do this stop right now. Eather buy a book on rebuilding your motor, find a buddy to help you or bring it to the machine shop and ask them to help you.

There is alot more to building a motor than just bolting everything together......

I am beginning to think that the bearings might be the wrong size.

Did you mike the crank to make sure the machine shop turned it down to the size they said they did?

edit: you did use setup lube...right?

im wondering if the guy knows what a torque wrench looks like... or if he goes on the "500 ftlbs and half a turn" methodology.