Bad piston!

[ejreams]

It depends how early you've caught it and considering you have issues, not early enough lol

 

[kacevedo3217]

Okay well thanks for all the help I just had a conversation with my father and he said he knew we had to do all the honing and balancing I just didnt know And my new struts and coilover sleeves should be here next week so ill have some pics up!

 

[x5carl3tMurd3rx]

I'm confused, your father is a certified mechanic and he didn't tell you all that you need. Also you paid 50 dollars for how many pistons? If a set of four, I seriously doubt the car will last through the break in period. Furthermore, you cannot just drop in new pistons drop the head back on and do so timing stuff then turn the key.

If you have a "bad piston" then the bore will need honing and AFAIK all the cylinders have to be symmetrical, so all four will have to be honed/resized. Then you'll need to rebalance the crank since the entire weight of the rotating assembly has changed. You've got a lot of work to do, assuming it can be done cheaper than the purchase of a used long block you should proceed, otherwise find a used F23 at a salvage yard.

^this...has alot of misinformation. you dont need to rebalance it, its not a race engine. honing is as easy as buying a hone you can put in a drill and running it up and down each cylinder a few times. rod bearings and main bearings should be replaced while the motor is apart. also the head studs are torque to yield so theyll need to be replaced. I personally would not put used pistons and rods in. they won't be clearanced properly for your cylinders and for all you know they aren't any good to begin with. you can buy a re-ring kit for pretty cheap and get a ring filer and file fit the new rings on your original pistons. arp headstuds aren't much more expensive then the stock head bolts so I would recommend them incase you have to pull the head again since they are reusable. only downside is you'll have to pull the upper IM off in order to drop the head back onto the block once its studded if your leaving the block in the car. Personally I'd pull the whole motor and rebuild it on an engine stand but thats just my preference. If you do everything properly and your diagnosis was correct the car should run perfectly fine and it won't cost you anywhere close to the price of a used engine with low miles.

 

[F23A1AT]

You'd run an unbalanced engine assembly even as a daily driver? Good luck getting it to last long it would shake itself to pieces. What am I misinformed about? I didn't tell him how to rebuild to engine, I just told him it wouldn't be the cake walk he seemed to think it was going to be.

You pretty much said the same thing I did with more words and few extra bits of ARP stuff.

 

[ejreams]

You both posted good info, just some difference in opinion

 

[98ExAccordwv]

I'm confused, your father is a certified mechanic and he didn't tell you all that you need. Also you paid 50 dollars for how many pistons? If a set of four, I seriously doubt the car will last through the break in period. Furthermore, you cannot just drop in new pistons drop the head back on and do so timing stuff then turn the key.

If you have a "bad piston" then the bore will need honing and AFAIK all the cylinders have to be symmetrical, so all four will have to be honed/resized. Then you'll need to rebalance the crank since the entire weight of the rotating assembly has changed. You've got a lot of work to do, assuming it can be done cheaper than the purchase of a used long block you should proceed, otherwise find a used F23 at a salvage yard.

My only problem with this is, when honing you should not be removing enough material to cause the cylinders to be non-symmetrical, Plus cylinders are going to wear at different rates, so the motor isn't perfectly symmetrical anyway. All you should be doing is creating a scratch in a cross hatch pattern.

Also, I've rebuilt several motors and re-balancing the crank is not necessary.

OP you can replace just the piston rings without doing anything else except honing the cylinder walls. This is what a reputable shop would do if you were to take it there and all that it needed the piston rings replaced. I would recommend replacing the rings on all the pistons as well as the rod bearings. It really won't add that much time to your job.

 

[F23A1AT]

What I meant by having to overbore was if the cylinder was damaged enough simple honing wouldn't suffice to fix the scratches. I know that I made a leap by assuming that, and posting what I posted was a bad idea in hindsight. I assumed deep scratching to the bore. You guys are saying that if the pistons were swapped for a completely different set that balancing the crank to the new weight of the pistons isn't necessary? That seems weird to me, but you learn things everyday.

 

[98ExAccordwv]

I understand your reasoning behind thinking the crank needs to be re-balanced, but think of it this way. These cranks are produced in mass and are never balanced to specific pistons that are attached. If you replace a piston with a "direct replacement" that is close to the original weight of the factory pistons (which they should be if they're direct replacement), then why would you need to re-balance? The piston should have no wear, they only change in weight would be from any carbon build up which should be negligible.

 

[x5carl3tMurd3rx]

my engine wasn't balanced in any way shape or form. boosted for a year and a hlaf with no issues and no paint shaker motor. When we replace rings on a motor at work we do it exactly the way I described. Thats the way my boss did my fathers toyota pickup's engine when I was like 13. That was using at least one new rod that was cracked somehow. even though he no longer owns the truck we know the guy it was sold to and to this day it still gets the guy to and from work everyday without anything other then general maintenance being done to it over the years. I'm now 22 incase your wondering how long ago this was. I wasn't trying to say your methods were wrong I was just saying that in order to keep costs and downtime to a minimum alot of it was unneeded. "misinformation" was probably a poor word choice haha.

 

[98ExAccordwv]

^basically the steps I provided him, no? I'm somewhat intoxicated, so reading your description right now and making coherent sense of it may not work out for me. Obviously I was not super detailed, but overall covered most of the main points.