Hey guys....Recently I rebuilt heads cause I had a couple burnt valves and I wanted to get it up and running so I could continue to diagnose the truck. I realized the other day after it was overheating only when the oil pressure dropped to near nothing that the bearings are probably shot. This brings me to my questions.....

How do I know what size bearings to buy as well as pistin rings? I can get standard or oversize .010, .020, .030. Is there markings on parts when I remove them? Do I have to use micrometer on bore? Is it wise to just replace entire crankshaft with bearings already installed? Can I leave the cam alone? The lifters looked fine when I did the heads. I cleaned them and they were ok. Need to get this RIGHT the FIRST TIME ONLY!!!!!! Please be sure with the answers!!! THANKS.

EDIT- Oil pump and pickup is brand new so you know...

 

What I did was take my crank to a machine shop and they turned it .010 over and got the .010 over bearings from Northern Auto parts. You really ought to have it done by somebody who can put the bare block in a hot tank and really make sure all the oil passages are clean. You can only get it so clean with cans of carb cleaner. Also you should have the tools to check the cylinders and head mounting surface and hone the cylinders if they check out ok. You need a telescoping thing I can't remember the name of and a micrometer to check the cylinder in a while bunch of places to make sure it's symmetrical. And a straight edge and feeler gauge to check the deck to make sure it's level. Basically unless you have access to all that crap it's easier to get someone to do it.

 

As for the cam you need to check the lobes and make sure they're not all worn down and if it's like a 3.8L you have cam bearings you have to replace as well.

 

1985 f150 302 FI 5.0 AOD


Thanks for the response. I got to do this on the cheap so I have to do it myself mostly. What I can do is take the block to a machine shop and tell them to clean it and check it and get dimensions from them. Then I can buy what I need correctly and do the rebuild myself. If they say the cylinders check out and they are xxx then I am good. I can hone them myself or if it is cheap have them do it. I may just get a new crank w/ bearings as if I remember it was like $150 at Rockauto. That leaves rings (which I will ask them what size I need, and rod bearings. I'll check the cam, but I am of the opinion its ok.

So:

Take block to machine shop.
Have them tell me info on cylinders and give me dimensions to buy proper rings.
Have them clean block and rebore/ hone if necessary.
Get new crank w/ bearings
Get rod bearings/ piston rings.
Bring block home and finish rebuild at home.
Already have rebuilt heads with less than 100 miles- will reuse and change gasket.

Sound ok??? I have dumped enough money and now I need to finish on the cheap. I know what I'm doing for the most part, but this is my first COMPLETE rebuild. Any pointers?

EDIT: Also, if having the crank turned is way cheaper I will have them do it too. I can at that point like you say get the right bearings.

 

150 for a crank and bearings is cheap, I had mine machined for $125 and paid around $100 for the bearings. Definitely get plastigage to use for when you torque down the bearings so you know everything is good with your rebuild. What you said is really what I meant for you to do, have them check everything and give you specs so you can assemble. As long as you have a manual, good torque wrench and plastigage you'll be fine. Honeing is easy, you just need a ball hone and a drill, but my guess is it'll be cheaper and easier to have them do it while they've got the block.