Loud Knocking/rebuild?

[macawlover70]

Hey all. I was driving home on Friday doing about 80mph when my engine started making what sounded like light lifter noise. I let off the gas and it went away so I accelerated and it came back . I slowed to 70 and it got alot louder really fast and I let off the gas and it died. i coasted to a stop and tried to start it and it started and even ideled but souned like someone was taking a hammer to the inside of my block. I 'm no expert at all when it comes to bottom end work but I think maybe I spun a bearing. Talk about depressed. I just spent a year redoing the top end (it took me that long because I could only afford one or two parts a paycheck) and now this. #%^#
A couple of questions though for those that have rebuilt or replaced rods, bearings, or pistons. If it is a rod or main bearing is it a good idea to just replace the bearings after checking the crank and fixing it if needed or would metal shavings in the engine be a problem? If I wanted to put new hi-pro oversized pistons for higher compression would I need to have the cylinders honed if the cylinders are ckecked out and are good or do I need to have the block bored? If I decide to go with the stock pistons can I just put new rings on the pistons that are in there now? My compression was 80 all the way across so my compression was very low. But, when I had the head off the cylinder walls were still crosshatched and looked awesome. Maybe I had worn rings. I was burning about a quart of oil in the month I drove it but it didn't smoke and I had NO leaks so maybe bad rings? Can I just replace the rings and bearings?
Second, lets say it's a broken rod. Can I just replace the rod and put it back together with all the other parts or should I have the crank checked and bearings replaced no matter what's wrong?
Third, if it's a spun bearing would you guys replace all the rods, pistons, bearings and have the crack done to tolerences anyway to avoid the same problem while the motor is out? Would you go with stock parts or hi-pro, new cam, new bearings etc, etc.
Any input will be appreciated since this is really my first time doing the bottom of a motor. I took one apart twice so I know where everything is but I don't know much else.
If I need to rebuild it from scratch and bore it and everything then I will let it sit for as long as it takes to get the money to do it but I want to do it right. But if I can just replace this or that and have a good dependable motor that's fine too.
Let me know and thanks again for your support guys and girls.

[majicwrench]

In a nutshell, if you have a spun bearing engine needs to come out and will need to be repaired. Crank turned or replace, connecting rod re-sized or replace. Needs to get cleaned out too.
If rod is broke (not likely, but possible) much worse, maybe damaged block, damaged crank, engine got to come out.

Replacing pistons, not neccessarily required when repairing the crank, bearing and rod issues. If pistons are ok, certainly you can just put rings on them. Cut ridge out of cylinder before removing pistons. If you are going to go to a higher compression piston, might as well bore block too.

You cannot just replace this or that and have a good dependable motor under the circumstances.Yank it out, tear it down and inspect.
Keith

[So Cal Mark]

if you only had 80lbs of compression in all cylinders, I doubt the motor would make much power. Cam timing comes into question when all cylinders are low. How is the oil pressure?

[majicwrench]

I wasn't too worried about that compression reading....his initial post said he was going 80mph, he would never get going that fast with 80lbs compression per cylinder!

[spidergirl]

Hi When I rebuilt my engine last winter I had a loud ticking noise. The good news for me was that onr the phenolic camshaft gears was loose on the metal hub. Thank goodness it didn't come completely loose or there would be parts mating together the shouldn't have. If your lucky that might be your problem.

Cheers Spidergirl