My engine needs rebuilding, is there any reason why...

[syclone98]

I can't pull it and replace just the parts that are needed?

I know some people might accuse me of trying to be cheap, but since I've got two engines that need to be done, I wanted to do a basic rebuild on what will be the daily driver and then splurge on what will eventually become the track car.

I've been researching various different options and found myself curious as to whether or not it's feasible to replace only the worn parts. My thinking was that I'd take it into the machine shop to have them examine everything and do the standard stuff (bore and clean, hone, new cam bearings and freeze plugs etc) and then figure out which parts could be reused before putting everything back together again.

The engine appears to be an unopened block with 106K miles that currently suffers from low oil pressure and what sounds like a rod knock. It still runs very well despite all this.

So...good idea or bad?

 

[84BuickGNYorkPA]

Of course that would seem to make the most sence, but... My personal opinion is that if you go through the trouble to take the motor out and disassemble it, which = lot's of wrenching time, you might as well take it to the machinist and tell him to do it right and be done with it. What I am trying to say is, it's already apart, do you really want to take the motor back out again before you have to?

Chuck

 

[syclone98]

I agree with what you're saying but I guess my question is this:

If a given part in the existing motor (crank, pistons, rods etc) checks out fine and it's the machinist who makes that determination (as opposed to me just installing some new bearings and blindly throwing the rest of the parts back together) is there any great advantage over using the existing parts as compared to installing brand new ones?

 

[turbot990]

do it right

just do what the machine shop tells you to do save your self alot of work and money put the new parts in spend the money and fix it perfect and enjoy what you installed its to much work not to do it right the first time and have fun . good luck

 

[84BuickGNYorkPA]

I agree with what you're saying but I guess my question is this:

If a given part in the existing motor (crank, pistons, rods etc) checks out fine and it's the machinist who makes that determination (as opposed to me just installing some new bearings and blindly throwing the rest of the parts back together) is there any great advantage over using the existing parts as compared to installing brand new ones?

Yes, listen to the priest, I mean the machinist, if your crank is good then that would be a waste of money... Oh I should back track for a minute, write your goals for the motor down and make sure you are up front with your engine builder/parts supplier. If you want big horsepower then maybe a forge crank is in order, but for the 85% of us the factory crank will meet our goals. The pistons are up for negotation, again depends on your goals, same with the cam, but as far as the rest goes, figure new rings at the minimum, all the bearings replaced, bores at least honed, oil pump, water pump(depending on age). Ect.

Chuck

 

[chopped39]

I take it is a 4.3. for what it is going to cost through a machine shop . Should be able to find a reman motor. unless you just hone the cylinders yourself and just rering it and throw a crank kit in it and recondition the rods. If it is knocking i would take the entire engine apart have block prepped and have all freeze plugs and cam bearings replaced. buy a complete rebuild kit from summit or jegs or call frank at gofaststuff.com .He can get eagle rotating assemblies for a pretty good price . Good luck

 

[syclone98]

No, it's a 3.8 liter.