Moparts
piston cleaning blues
Posted By: Moparnut426
piston cleaning blues - 01/05/09 04:25 AM
Well Im rebuilding a 360 magnum for one of my customers, and the block Im using for him is my dad old van engine. It has 250K+ miles on it, but I knew it was well taken care of. Anyways, Im cleaning pistons now, and Im getting all the carbon buildup behind the rings off and it sucks. The magnum rings are very thin, and my ring groove cleaner wont work on the top 2 grooves. Im using a broken ring and chisling away. They have been soaking for days, but still comes off like it part of the piston. Anyone know of a chemical that eats the carbon off pistons??
Also are the magnum 360's and the LA 360 balenced the same. I need a flywheel for a 360, and dont have one for a magnum.
Kasey
brake cleaner will remove that krap. ps, no chiseling! the rings have to seal against the sides of the ring grooves, and the fit and finish must be preserved. save the seal!
Posted By: Moparnut426
Re: piston cleaning blues - 01/05/09 04:32 AM
I know, Im not really chisling, Im being patient, but my wore out fingers are taking a beating, but thanks for the heads up though.
Posted By: dOrk !
Re: piston cleaning blues - 01/05/09 04:34 AM
Are you sure the pistons are worth saving? ...check the ring groove clearance to be sure.
I hear that that high-dollar one-gallon-can of carb-cleaner works great.
spray or soak in brake cleaner, and a toofbrush work great! in the olden days we had carb cleaner that would make los pistones look brand new, but i'm afraid those days are gone. i got the latest, greatest carb cleaner, and it didn't work worth didly.
Posted By: Moparnut426
Re: piston cleaning blues - 01/05/09 04:43 AM
I was just going to ask if that stuff would work.
I used that stuff before, the good stuff, it damn near cut through the aluminum base plate, I left it in too long.
Posted By: Cab_Burge
Re: piston cleaning blues - 01/05/09 04:44 AM
Have you tried soaking them overnight in soapy water? That really softens the carbon up to almost like putty. I'm sure you check the block for taper befroe starting to make sure that motor will seal with the old pistons and a news set of rings, right? 250,000 miles without a bore job is a really good motor
Posted By: Moparnut426
Re: piston cleaning blues - 01/05/09 04:54 AM
It honestly is in GREAT shape, Its got some taper, but nothing that wont seal. The thing still had a good cross hatch in it. Almost nothing for a ring lip. I could barely feel anything, and the pistons came out with even resistance all the way out, never got cought at all. Its a budjet build, and my customer will barely put any miles, or hours on it, it going in his combine.
I forgot to mention its a 98 magnum 360 that was fuel injected.
Posted By: Anonymous
Re: piston cleaning blues - 01/05/09 04:17 PM
I scraped the carbon off the tops of mine with a broken piston ring and then threw the rod/piston combo in the dishwasher when the wife was at work. Came out lookin' like new!
SHHHHHH!
Posted By: Thumperdart
Re: piston cleaning blues - 01/05/09 05:31 PM
We just did a freshen up a few months back on a local bracket racers motor and good ol fashoned laquor thinner works awesome then attack the tops only w/a soft wire wheel and your good to go.
Posted By: TS3303
Re: piston cleaning blues - 01/05/09 06:03 PM
cheap table top ultrasonic cleaner with a little simple green works good, unfortunately you can only fit two at a time. I use mine for everything, car parts, nuts & bolts, jewelry, printer heads, etc. When done throw the SS tank in the dishwasher and clean as new.
Posted By: Monte_Smith
Re: piston cleaning blues - 01/05/09 06:18 PM
Its got 250,000 miles, "some taper and a lip you can barely feel"...it's wore out brother. Save your time cleaning those pistons, toss them in the trash, buy some new ones and bore the block.
Monte
Posted By: Moparnut426
Re: piston cleaning blues - 01/05/09 06:21 PM
Its really not wore out, I know a shot block when I see one. Its gonna be fine for what its gonna do. The customer just wants it for a few thrashers bees, and that it, so It might get 10 hr on it a year. then it going to be in his shop with all his other restored farm equipment.
I have rebuilt was worse engines and had no problems. I just wanted a faster way to clean pistons.
This guy doesnt have a very deep pocketbook.
Kasey
Posted By: Challenger 1
Re: piston cleaning blues - 01/05/09 06:23 PM
Quote:
Its got 250,000 miles, "some taper and a lip you can barely feel"...it's wore out brother. Save your time cleaning those pistons, toss them in the trash, buy some new ones and bore the block.
Monte
I'm thinking the same thing. 
Posted By: Monte_Smith
Re: piston cleaning blues - 01/05/09 06:34 PM
Combine or not, you are going to have to hone the step and the taper out for it to seal. How big will it be then?
Monte
Posted By: Moparnut426
Re: piston cleaning blues - 01/05/09 07:13 PM
Again, its gonna be fine, Its not perfect, the customer knows that hes fine with it.
Posted By: DaytonaTurbo
Re: piston cleaning blues - 01/05/09 07:29 PM
Quote:
Combine or not, you are going to have to hone the step and the taper out for it to seal. How big will it be then?
Monte
Thousands of engines have been "rebuilt" like this and run just fine. Deglaze, new set of cheapo cast rings and go. No one's claiming it's as good as new but it'll be a definite improvement.
Posted By: Bob_Coomer
Re: piston cleaning blues - 01/05/09 08:01 PM
A easy way to see the taper is to put a used ring in the cylinder up at the top square it up, measure the gap, then push it to the bottom of the bore and remeasure. Im betting .008+
But should probably last 100K anyways, might start using oil pretty fast though
Posted By: dOrk !
Re: piston cleaning blues - 01/05/09 08:06 PM
LOTS of bore taper will make the rings wear-out the ring grooves in the pistons. And with lots of clearance there .... the rings will never seal correctly or even in some cases -- seat.
Posted By: Moparnut426
Re: piston cleaning blues - 01/05/09 08:12 PM
You guys are killing me!!
If it doesnt seat, Ill just dump some AjAx down its throught!! LOL, just kidding.
comet is better. not too much. maybe a cup or so. coffee grounds mixed with cinder will do in a pinch. iron filings are also excellent.
Posted By: TX91971
Re: piston cleaning blues - 01/05/09 10:18 PM
Hey guys he is probably right I worked with this bracket racer he would take his 100,000 mile 340 motor out every year and hone the cyl with a ball hone and put used rings back in the motor not the ones that came off the pistons because they were all broken and run most of the year consitent car 13.30's and when it would slow down he would take it out and replace the broken rings with other used rings. He also put cam bearings in with a long extension and hammer and it ran fine. I talked him into letting me put electronic ignition in his car in 1992. Dual points before that. When your on a budget that's the way it is. This guy was Heavy eleminator champ at a local pa track for many years in a row.
Posted By: Monte_Smith
Re: piston cleaning blues - 01/05/09 10:29 PM
Will it run, sure. Will it be right, no. I understand all about budget and doing something cheap, but I still think it should be done right. Cast pistons are dirt cheap and a bore hone is not expensive. The whole process could likely be done for 150 bucks, with pistons. IMO, if you could not afford that, he should of just left the 250k shortblock assembled and went as is.....but I do realize that he was not asking for opinions, he only wanted to know how to get the carbon off. Seeing as that is the case, I am removing my
from this discussion and should not have commented in the first place.
Monte
Posted By: Moparnut426
Re: piston cleaning blues - 01/05/09 10:51 PM
Monte,
I totally understand where you are coming from, but in this case, The customer only has about X amount of $$$ and our machine shop charges about 350 to bore the block, and pistons cost 150ish, and then you have to press the old ones off, and press the new ones on, all costs money the customer just didnt have.
We will be fine.
Thanks and If it was mine, and I had the cash it would get bored, Never said it was a perfect world.
Not disagreeing with you at all, but certain things just have to work on a budjet.
Kasey
Posted By: thecarfarmer
Re: piston cleaning blues - 01/06/09 12:00 AM
Yeah, it'd be better to replace the pistons, but... I'd try some aircraft paint stripper if I was going to try and reuse 'em.
Aircraft stripper is formulated to not eat aluminum. Seems to me I put some on some carbon and it chewed through it like Rosanne Barr on a chunk of roast beef
-bill
Posted By: dOrk !
Re: piston cleaning blues - 01/06/09 09:06 AM
Quote:
Will it run, sure. Will it be right, no. I understand all about budget and doing something cheap, but I still think it should be done right. Cast pistons are dirt cheap and a bore hone is not expensive. The whole process could likely be done for 150 bucks, with pistons. IMO, if you could not afford that, he should of just left the 250k shortblock assembled and went as is.....but I do realize that he was not asking for opinions, he only wanted to know how to get the carbon off. Seeing as that is the case, I am removing my from this discussion and should not have commented in the first place.
Monte
150$ for a bore and hone WITH pistons?
Have I got some work for that shop you deal with !!!
Posted By: Moparnut426
Re: piston cleaning blues - 01/12/09 02:07 AM
Well I used paint stripper paist, and It wouked GREAT!! Thanks for the help, and I got 4 done in no time flat, I have 4 left, and 1 is soaking.
I appreciate the help guys
Kasey
Posted By: hemi-itis
Re: piston cleaning blues - 01/12/09 03:21 AM
Quote:
Will it run, sure. Will it be right, no. I understand all about budget and doing something cheap, but I still think it should be done right. Cast pistons are dirt cheap and a bore hone is not expensive. The whole process could likely be done for 150 bucks, with pistons. IMO, if you could not afford that, he should of just left the 250k shortblock assembled and went as is.....but I do realize that he was not asking for opinions, he only wanted to know how to get the carbon off. Seeing as that is the case, I am removing my from this discussion and should not have commented in the first place.
Monte
Good thang ya dudn't sugjezt a cam change Her's yer change 
Posted By: 2boltmain
Re: piston cleaning blues - 01/12/09 05:26 AM
When I was a kid a local snowmobile racer would glass bead blast his pistons. Said it cleaned em up real nice but didnt effect the material.????? High school auto shop teacher would soak them in chem dip carb cleaner. (The shop had a 30 gallon drum) That was 20 years ago. I think the formula now is different and hard on metal?
Posted By: 1_WILD_RT
Re: piston cleaning blues - 01/12/09 06:02 AM
Quote:
When I was a kid a local snowmobile racer would glass bead blast his pistons. Said it cleaned em up real nice but didnt effect the material.????? High school auto shop teacher would soak them in chem dip carb cleaner. (The shop had a 30 gallon drum) That was 20 years ago. I think the formula now is different and hard on metal?
It's different but it's not that it's hard on metal...It's ineffective or carbon... EPA approved...