Brad_and_the_AC

Ok first off, this board is VERY friendly and helpfull. I have had quite good experiences with this forum so far.

I have been having problems with my car (97 Honda Accord lx, 4dr *turbo*) for a few months now. First the car was acting weird, like bogging down before the turbo would "spool". Then the timing belt broke while I was on the highway. Had some head work done, mild P&P. Replaplaced bent valves, and yada yada yada. So the head was back on and still having some problems, but now my problems where from when I was "in" boost. So my buddies looked around and discovered an exhaust leak, you could actually hear it so it wasnt like we had to look hard for it. Welded up the exhaust mani, and I also had a wastegate problem and fixed that aswell. The car was STILL not running right. Checked compression, Good. So the night before last I decided it could be a fuel problem. So I changed the fuel filter, that was a BEECH btw, the incredible hulk put that thing on, lol.
So this is where the story gets sheetie.
On my way home from my dads backyard shop (about 10 miles away) I started to hear a knocking . So I get home and sure enough #3 has a bad knock. . A ringland or a rod.
I have been looking at used motors, but I JUST rebuilt the head 2 weeks ago so a high milage motor is out of the question. You know I just dont want to spend 700 on a new-used motor and strap my turbo up to it and blow it up before I get off the block. The motor I have now I have "babyed" to the fullest, even though its been turbo for almost 50,XXX miles now. I have pampered that thing like crazy. So Im just going to do a "short block rebuild".
So I went back to the shop and talk to the mechanic.
The machine shop guy said we should "bore" the block. I am just not understanding why. He says anything else would just be a "bandaid". I figured It would just be a "hone" and "ring" job
So my question is if I just did a "standard" bore would I need to upgrade the ECU and FUEL delivery? Or is it going to be so close to the same it doesnt matter?
I am kinda stumped on the whole thing. I am going to be the one pulling the motor, and I am pretty tech inclined just am unsure and I have spent ALOT of money on the car and want it to go GOOD from here on out.

As you can tell I have never had to do a full rebuild. Even though It sux that I have to do it, Im actually looking forward to doing it. Just for the knowledge.

Sorry for the wall-o txt its just I wanted you to understand what I have went through in the past few weeks.
Thanks in advance!

Brad_and_the_AC

Bump....
summary
*would I need to to upgrade fuel delivery after rebuilding my motor with a "standard" bore?

Brad_and_the_AC

BUMP....
Nothing?

Volt-Schwibe

I can't precisely say why your machinist thinks anything short of a bore job would be a band-aid. Perhaps he is just talking about reaming the ridge down, and putting a nice cross hatch on the cylinders, but if he's not, then you should ask specifically why. If he's talking about getting more power out of it, then you should have the choice to do it or not do it. If there's something he knows that i don't, i'd love to hear it, but from all my experiences, people don't just bore cylinders out for fun, there's usually some good firm logic behind it. So, i'd suggest asking him to explain why reaming and honing isn't sufficient, and hopefully it makes sense. Sometimes, after an engine has ran for a long time, the cylinders all end up different exact sizes, and here's where alot of mechanics decide to bore it out, so that they all end up the same, and then you'd order a new matching set of rings, and pistons if the difference is past a certain threshhold. So, there could be good logic in what he's saying, because this is a turbocharged high output engine, balance is more critical, and having all different size rings could wear it out prematurely.

Alot of people are quick to assume a mechanic doesn't know what he's talking about, or are just looking to sell you parts, but i try to look at it objectively, and see why he's recommending what he is. Your machinist might be completely right, or he might just be wanting to boost your power.

As far as changing your intake to match it, that's not as critical as you'd think. The auto industry has always used the intake to control the "working volume" of the engine, so if you bore your cylinders larger, the intake will still make the motor perform like before, unless your intake was already higher volume than your engine could use, and then you willl see a power increase. With the turbo, this might be the case here, so in short, i don't think you'd have to replace your intake.

The ECU computer won't know the difference, but that won't matter anyhow.

I hope all that helps.

majorahole

yup, it won't make a difference.
but if it did, you do have a wideband right??
all non-factory turbo cars should.

Brad_and_the_AC

yes I do have a wideband that controlls/monitors a/f r.

majorahole

then you can tell if it will make a difference, as it shouldn't mess up your timing