I am looking to rebuild my engine for the first time and curious about what I should do. I'm fairly sure that I need to replace the main bearings and/or oil pump. What I am wanting to know is whether I should do a master or re-ring kit?

When I had the heads off a few months ago I didn't notice any significant damage or signs of wearing from the pistons, at least on the surface. Anyone that's rebuilt an engine, what would you recommend? I want to be as lite on my wallet as possible but I also don't want to be in the same situation in a few months or years for that matter.

 

well, if i was rebuilding a motor it would get:

-block and head sent to machine shop to have heads checked for straightness, valve seats checked out and everything cleaned.
-Have cylinders measured for evenness, get appropriate sized pistons and have it bored to the size of the pistons
-new bearings and bushings of any kind (main, rod, cam, balance shaft, piston rings)
-have cam checked out but it will probably be ok
-new valve springs and seals
-new valves if it seems needed, have valve seats done to new valves

However if you want to be cheap just be smart, you may not need to have it bored over and leave the pistons, but if you go through the trouble of getting it out may as well do what you can. If it burnt ANY oil dont go cheap on the valve and piston/cylinder wall work. DON'T run a new motor hard untill its have at least 5,000 miles on it. Change oil after running for 1000 miles after rebuild. First time you get it together make sure its running good and not leaking everywhere, have a nice long drive with it (long enough to get everything up to temp). Put Lock-tite on the flex plate bolts.

 

How would I go about checking everything? I know that there are some obvious signs if the pistons and walls are needing a honing or to be bored out. To really determine I know that a measuring needs to take place but not sure exactly what the measurements should be for it to be within spec.

What I am going to do first before anything is pull my block and give it a good look over to determine exactly what needs to be replaced. I do plan on running at the very least a ring and valve job due to a limited budget and as needed I will invest in the other work that may be needed like being bored out.

Any suggestions on how I can take measurements or find what the measurements should be? I do have a chiltons book so I will begin there and see what I can find.

Also are there any posts here that cover rebuilding the motor?

 

If you can get ahold of a telescoping gauge to check the roundness of the bore. They tend to oval out. I would say a .010 difference would warrent machine work. If your engine didnt smoke or consume much oil it may be good. Just remember torque specs!

 

I've been trying to find a rebuild kit but not finding what I'm looking for so to speak. The best one I have been able to find is the MKP6020C that is on Summit Racings website or the DNJ kit listed on autopartswarehouse.com which does not include an oil pump. I've been trying to find a kit that includes all the bearings and gaskets that I'll need plus the oil pump but I don't necessarily need the pistons. If I do a rebuild is it best to do it with new pistons? Or should the ones already in the block suffice?

I also found the list below that looks like it includes everything needed. Now if I were to get all that, minus the pistons and add the oil pump, that should be everything that I am looking for right?

Has anyone had any bad experiences with DNJ parts? Are they fairly reputable, or would I be better off going with the Felpro kit through summit?

2000 Chevrolet S10, Engine: V6 4.3L 262cid OHV Engine Master Rebuild Kit
Part# Click to buy DNJ EK3129 (VIEW IMAGE)
Your Price: $276.11
Engine Kit Includes the following parts:
MAIN BEARING SET STD (MB3125)
PISTON SET STD (P3127)
CAM BEARING SET (CB3125)
PISTON RING SET STD (PR3127)
ROD BEARING SET STD (RB3125)
LOWER GASKET SET (LGS3129)
FREEZE PLUG SET (FPS3125)
HEAD GASKET SET (HGS3129)

 

Like AndrewO said, best to have block and heads taken to a (reputable) machine shop to be checked out. The can even sonic check for cracks, in addition to just measuring. Having it hot-tanked is nice for cleaning out all the little passages, also.

If no overbore is needed, the stock pistons will be fine with new rings.

Also, don't have it overbored more than necessary. If it will clean up at 0.010" over, no need to go 30 or 40 over. A lot of guys (with small blocks, anyway) bore it as much as possible to get more displacement (like the extra 4 inches will do anything...). You are limiting the number of future rebuilds on that block by doing that.

The most expensive part of any rebuild is machine work. But there's no sense in putting a worn out, out of spec motor back together.

I have to ask, though. If the engine wasn't burning oil, and assuming it ran before, why are you rebuilding it? It's only 13 years old. Heck, I've got 252K on mine, and it is nowhere near needing a rebuild!

 

While mine is no has no where near as many miles as yours does I can definitely understand where you're coming from here. I was hoping I wasn't going to have to go through a process like this for many years to come. A few months ago I started to have low oil pressure, at least according to the gauge, I did not check it with a manual gauge to see if it was just yanking my chain or not so I kept driving. Not so long later I started hearing a knocking come from the engine. I checked my oil level and that was fine, couldn't think of any other reason why it might be doing what its doing. I did a bunch of research and discussed it with my dad, who has done his fair share of work on cars (not a mechanic by any means but he's rebuilt a block or two) and determined that it sounds like either the bearings are shot (if I remember reading it correctly when I did) or the oil pump is on its way out and he agreed that I should probably sideline the Blazer until further notice.

I've been hoping for a long time that maybe its something else, who knows, maybe when I go to pull the block out its something completely different is wrong. Shortly before I sidelined it I did replace the head gaskets and now I noticed that there is a puddle of oil under my engine, so Im not sure if its maybe because of the oil leak that might have been the cause of my issue the whole time or what. Im looking to start stripping parts soon to see if I can find the root cause.

Any ideas that you guys might think of?

 

Yeah, with no oil pressure, and a knock, it's definitely time to start tearing it down! Sorry about your luck!

 

my boss runs a motor shop and helping him out from time to time i would say what you need to do is the following.
get the motor tore down
have the heads resurfaced. they wont need to take much off so long as they are still flat.
GET A VALVE JOB-even with a few miles on the car, carbon builds up and the seats get a little beat up. all you need is whats called a 3-angle valve job and have the valves faced. and all the springs should be checked as well.
as far as the block goes-
you have to have it HONED. you dont need to get it bored unless its fairly oval-ed out. MOST of the time getting it honed is all you need.
you will need all new compression, wiper, and oil rings for the pistons.
new bearings all around INCLUDING the cam bearings.
and then of course a gasket kit for everything.
the head gasket kit should include lower intake, head, valve cover and exhaust gaskets.
then you need oil pan and timing cover gaskets.

i hope that i didnt miss anything.

i know its a lot, but if you go cheap on it, you are going to regret it later on. but you need to buy some good parts and gaskets so you dont have to worry about it later on and then spend more and more money.
good luck with everything. and if you can, take plenty of pictures.

 

A tip to help you keep track of things. Take pictures as you remove each piece. This will be helpful if you cannot remember things. When you get to removing the rod caps. What I do is I use an engraver (from harbor freight) to etch the cylinder number on the caps and the rods ( on the side that faces out. This keeps helps keep track of which cap goes on each rod and also I know that the piston is pointed in the right direction when I am building back up.