Did I?

JosieGallows · Apr 21, 2014

Did I take too much material off the skirts of the pistons when resurfacing the skirts using scotchbrite? I tried to get the scuff marks smooth so it wouldn't jam in the block.

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Too much or too little?

fordf350man · Apr 21, 2014

pretty sure there is a coating on the pistons, i was always taught to never touch the skirts of a piston, only the tops of them, i think you can have them re coated though, others will chime in that have more experience with this but you can do a search on here, should come up

JosieGallows · Apr 21, 2014

fordf350man said:
pretty sure there is a coating on the pistons, i was always taught to never touch the skirts of a piston, only the tops of them, i think you can have them re coated though, others will chime in that have more experience with this but you can do a search on here, should come up

They were uncoated.. I surfaced them with Green scotch brite.. Grey is to fine and Red is to coarse. So Green seemed to work ok.

They were heavily scuffed so I really had no choice, I was told to do so by a mechanic.

fordf350man · Apr 21, 2014

im not sure, i have always replaced a piston if they seemed to be scratched up, but that is me there will be some more on here when they wake up to help you out, my opinion for what its worth is looks good to me

OLDBULL8 · Apr 21, 2014

OEM pistons go thru a wash just before the weighing, that wash contains Zink phosphate to coat the pistons just for Hot Test break in, been a long time ago but IIRC.
It would take a lot of scrubbing with Scotch Brite to take 0.0005 off a piston.

Edit correction: The pistons are washed then go thru a dip tank with the Zink Phosphate in it.

icanfixall · Apr 21, 2014

Pistons being the softer material will scratch quicker than the cylinders but.. Why are the pistons geeting this scaring on them is the real question here. As posted. You really can't remove enough to ruin a piston but measuring it is a good idea. Replacing them is really the best option. That will require boring the block too. I personally have never heard of cleaning off the scratches like you have been told. I would do it if these were the last pistons on earth and I wanted to repair and run an engine. How many miles were on the engine is a good question too. What care was taken too. I think the worst thing that can happen if you took off too much is the pistons will slap the cylinders as its running. That will make a piston slap noise that might be offensive to you. It wont harm the running engine.

JosieGallows · Apr 21, 2014

icanfixall said:
Pistons being the softer material will scratch quicker than the cylinders but.. Why are the pistons geeting this scaring on them is the real question here. As posted. You really can't remove enough to ruin a piston but measuring it is a good idea. Replacing them is really the best option. That will require boring the block too. I personally have never heard of cleaning off the scratches like you have been told. I would do it if these were the last pistons on earth and I wanted to repair and run an engine. How many miles were on the engine is a good question too. What care was taken too. I think the worst thing that can happen if you took off too much is the pistons will slap the cylinders as its running. That will make a piston slap noise that might be offensive to you. It wont harm the running engine.

139,000 miles, pistons removed due to cavitation damage, resleeving block should be done by Friday.

The thing is, the oil retaining lines are still there, you can rub your fingers on them and feel them. So I don't think I took too much off, just enough to smooth the scoring.

icanfixall · Apr 21, 2014

My thoughts are if you sleeved all 8 cylinders then please replace all the pistons. If you sleeved only the cavitated cylinder then replace that piston and rings along with the rod bearing.

JosieGallows · Apr 21, 2014

icanfixall said:
My thoughts are if you sleeved all 8 cylinders then please replace all the pistons. If you sleeved only the cavitated cylinder then replace that piston and rings along with the rod bearing.

I can't afford it. I just turned 17 a few days ago and I am broke now. New pistons cost $670 on eBay ceramic coated from Mahle. They come with rings and pins too.

I'd buy them if I had $670 to lay out man.

Now I want a honest answer, do you think these pistons will make it to 100,000 miles?

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I mean I suppose I could save for new pistons, but the truck needs tranny work too and I figure I could put the $600 into that.

riotwarrior · Apr 21, 2014

Wow, seems like such a waste, those pistons will work however not well like a new set.

If you have been told this by a mechanic why not ask him? Why come here after the fact and propose this question?

You may feel the grooves but in comparison to new pistons they are well worn, not only that now the skirt won't hold the oil as well as it can with the grooves. That wear is from the piston rocking in the bore some and lack of oil. Now you are going to put worn out pistons into practically a new block?

Why did you not try to find a good running engine instead of doing this level of machine work, sleeving the block and then using old worn pistons?

May as well wear a ****** and then rinse and use it again to save money too!

As I said in PM before we here know what it's like to be young, however we are also aged and have enough experience doing this stuff to really offer solid advice.

Seriously get new pistons, if they /hone/bore those sleeves to match the used pistons I'll be amazed, as the sleeves need honing to match the pistons that are going in.

Good luck with this however you choose to do it.

K-nite · Apr 21, 2014

That piston looks fine cleaned up. Use new rings. Clean off all the carbon. Check the pistons for cracks around the ricardo cup, recess. Clean out the ring grooves real well, check for any abnormal wear in the grooves, ring clearance in the groove. Check for clean smooth pin bore and free pin movement. Smooth out any dings from disassembly and handling. You should be good to go.

JosieGallows · Apr 22, 2014

riotwarrior said:
Wow, seems like such a waste, those pistons will work however not well like a new set.

If you have been told this by a mechanic why not ask him? Why come here after the fact and propose this question?

You may feel the grooves but in comparison to new pistons they are well worn, not only that now the skirt won't hold the oil as well as it can with the grooves. That wear is from the piston rocking in the bore some and lack of oil. Now you are going to put worn out pistons into practically a new block?

Why did you not try to find a good running engine instead of doing this level of machine work, sleeving the block and then using old worn pistons?

May as well wear a ****** and then rinse and use it again to save money too!

As I said in PM before we here know what it's like to be young, however we are also aged and have enough experience doing this stuff to really offer solid advice.

Seriously get new pistons, if they /hone/bore those sleeves to match the used pistons I'll be amazed, as the sleeves need honing to match the pistons that are going in.

Good luck with this however you choose to do it.

Hard to get a 7.3 IDI Turbo that doesn't have cavitation damage.

The mechanic who's sleeving the block told me to resurface the skirts.. I made it clear the truck needs a trans rebuild, a new front-end, and lots more. Can't spend $600 on pistons when I can reuse these.. I'm going to put new rings and bearings in them anyways.. Do you have any idea how much $600 is?

Sure I spent $800 on the block sleeving, buuuut that was because you cannot reuse a cavitated block, but you can reuse pistons... The new cylinders would mean a very tight fit right?

I don't plan on towing, just everyday driving. Not to mention I'm going to be using 6.9 cups instead of the 7.3 ones.

To sum it up, I spent all my money on the machine work. What could happen at the worst reusing them?

riotwarrior · Apr 22, 2014

JosieGallows said:
.. Do you have any idea how much $600 is? .............what could happen at the worst reusing them?

YES,

Enough that if it does go sour you will be out a lot of cash....Lets just hope this turns out well and runs strong

JosieGallows · Apr 22, 2014

riotwarrior said:
YES,

Enough that if it does go sour you will be out a lot of cash....Lets just hope this turns out well and runs strong

I'm f*****g with you on that one brother 110%. Sorry for swearing but, I sure hope it does turn out good and runs strong. I gotta take this thing from Memphis,TN to Tampa,FL!!

The 6.9 cups should make the engine sound louder and give me some better MPGs. The only reason the 7.3 cups came into existence was for emissions. The smaller displacement 6.9 cup would mean more fuel gets burned in the main chamber.

So I hope it gets me to Florida and back and forth to work and whatever else I need to do

Knuckledragger · Apr 23, 2014

The question that needed to be answered first is why the piston got scored like that? If the engine is still apart a little bit, make sure all of the oil squirters are clean. They were removed for sleeving, so I hope they were examined at that time.

I have no particular problem reusing pistons, especially since you can make the cylinders fit with the new sleeves. It is the rings that might be a problem if the ring grooves have any excess wear.

Did I?

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