No he does not "have" to coat them at all. He asked if he could. Thermal barrier coating is a nice addition that can actually show power on the dyno if you have the extra money to spend on it.
Piston dome question?
- Thread starter Captainkirk
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He could also coat the heads chambers and back side of the exhaust valve.
I am not arguing the point, because Lord knows I am out of my element discussing this. But, I have read where coating both the head and chamber cancels out any benefit. I have not spent a ton of time readin up on it, but that is one point I remember. That of course could be completely wrong, consult your closest thermal coater for correct information. lol
Captainkirk
Old School Mopar Warrior
...I think it came out pretty decent.
Hell yeah.
Damn! You could almost use that as a mirror. Pretty decent? At least, LOL.
W2-1969Dart
Well-Known Member
These guys are pretty good at coatings. I have used them lots.
http://swaintech.com/race-coatings/
http://swaintech.com/race-coatings/
Captainkirk
Old School Mopar Warrior
.....we ain't outta the woods yet, Georgie.
While my recent posts have solved several questions regarding these pistons, specifically the forging flaw on the dome (and whether it could be polished out; indeed it could and was) and the resulting weight difference (I've been assured it's okey-dokey to match them all to the lightest piston...have grinder, will travel!) there is still a burning question gnawing at my guts...I've got some pitting and corrosion in several of the ring grooves and on the lands and skirts that I've found since disassembling and cleaning.
Can it be polished out? I dunno....part of me is screaming "Chuck these things in the trash, dammit!"...yeah the same part that screamed the same thing when I found the forging flaw. And look how that turned out!
I guess there's nothing left to do besides give it the old college try and see what happens.
I guess ring grooves are a bit more critical than the domes.
Am I nuts to try to clean this up? (even though I'm gonna try?)
While my recent posts have solved several questions regarding these pistons, specifically the forging flaw on the dome (and whether it could be polished out; indeed it could and was) and the resulting weight difference (I've been assured it's okey-dokey to match them all to the lightest piston...have grinder, will travel!) there is still a burning question gnawing at my guts...I've got some pitting and corrosion in several of the ring grooves and on the lands and skirts that I've found since disassembling and cleaning.
Can it be polished out? I dunno....part of me is screaming "Chuck these things in the trash, dammit!"...yeah the same part that screamed the same thing when I found the forging flaw. And look how that turned out!
I guess there's nothing left to do besides give it the old college try and see what happens.
I guess ring grooves are a bit more critical than the domes.
Am I nuts to try to clean this up? (even though I'm gonna try?)
MAN!!! those are the prettiest piston tops I've ever seen..ever
....before you make those grooves just as clean and spend a truly dedicated
effort on them(with excellent results I must add)
please take a measurement of the piston skirt. If that number is (whatever)
If it's good, clean the groves....everything was OK until the pic of the side.
Did you keep them in the block or disassembled. Did they come out easy or did you have to whack them a bit harder to get them started??
That favors dissimilar metal corrosion, like steel and aluminum?
PM me your email and I'll send you pics from a couple sets-used and unused and a set
with the tops cut off (my original set).
If you want to have some fun clean them up, 0 deck, some ol style steel rings and
decent set of 202s (63-65cc)for about 13.5-1 which will require big octane and
have the blast of a lifetime just like was done like it was "yesterday"..........
....before you make those grooves just as clean and spend a truly dedicated
effort on them(with excellent results I must add)
please take a measurement of the piston skirt. If that number is (whatever)
If it's good, clean the groves....everything was OK until the pic of the side.
Did you keep them in the block or disassembled. Did they come out easy or did you have to whack them a bit harder to get them started??
That favors dissimilar metal corrosion, like steel and aluminum?
PM me your email and I'll send you pics from a couple sets-used and unused and a set
with the tops cut off (my original set).
If you want to have some fun clean them up, 0 deck, some ol style steel rings and
decent set of 202s (63-65cc)for about 13.5-1 which will require big octane and
have the blast of a lifetime just like was done like it was "yesterday"..........
Captainkirk
Old School Mopar Warrior
I'm ashamed to say they've been in a box on the floor of my garage for longer than I care to admit.
When I disassembled the motor and had the block work and balancing done, the shop mic'd the cylinder bores and pistons at the time and said they were good to go. I will mic them myself but the wear appears minimal. I think the pitting was due to sitting in an unheated garage unprotected....my own damn fault.
Still, I think they *might* clean up.
I will PM my addy. I'd like to see some pix of these with milled domes.
When I disassembled the motor and had the block work and balancing done, the shop mic'd the cylinder bores and pistons at the time and said they were good to go. I will mic them myself but the wear appears minimal. I think the pitting was due to sitting in an unheated garage unprotected....my own damn fault.
Still, I think they *might* clean up.
I will PM my addy. I'd like to see some pix of these with milled domes.
ALL the piston can be bead blasted except the skirts. Glass bead blasting will take care of that problem in the last picture.
Captainkirk
Old School Mopar Warrior
Actually, I think Scotch Brite and a ride on the polishing wheel will cut most of that off there without removing any metal. More worried about pitting damage than anything.
Not critical at all.
Captainkirk
Old School Mopar Warrior
Cool. You have a way of making my day sometimes!:burnout:
If it was on the skirt area then we'd be a little concerned. Just polish it up good and it will be fine.
moper
Well-Known Member
I'm much more concerned about the condition of the inside surfaces of the ring lands. The perimeter of any piston where the ring grooves are never comes near the cylinder walls and could look like a golf ball and have no issues. But - the top ring particularly HAS to seal against the top and bottom of its groove (at different times during a 4 cycle period) and if that doesn't work well, the rest is all moot. Do those pits go into the ring grooves at all? BTW - do NOT blast the ring grooves. Use a wire wheel or scotchbrite by hand. The only areas of a piston that can be safely media blasted is the top of the dome. Which in your case looks like a very pretty ash tray 
.
.
I've blasted ring lands by the hundreds and never had issues. You don't want to do it with anything anymore course than glass bead though. Walnut shells are even better if you are a novice to blasting.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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A buddy and I found a 340 in a junkyard once( thats what they were called back then) that had been sitting there with no weather protection. He bought it for the heads and intake. It had at one time sat with water on top of the pistons. Well I got the short block for payment for doing the swaperoo onto his 318. I was 18 or 19, or maybe 20.
Well I had this blown up 318 laying around, and now this fugly pistoned 340. Well now, you can guess the rest. One bank of pistons had pits the size of half-BBs.I spent some hours on it (hey I was still living at home and unemployed) And put that teener top end on that junkyard 340, with nothing more than a set of 340 springs, and dont you know that conglomeration ran gangbusters.Well at least in my mind.I think I might still have that beast around here somewhere.
Just reminiscing. I wonder if you arent worrying a bit overly.If youre gonna run 10/10ths, Stuff gets real important. For street motors not so much.
My brother told me a good story. Seems he and some rascally buddies were out bush-partying this one time and got a bit crazy. They had this beater 74 Duster that body-wise was done. Well they fired it up and bricked the gas pedal wide open. After about a half hour of that( not my story) they got tired of the screaming teener.Well one brave young boy figured out how to get it shut off. Well of course it didnt run after that so they gave it to me. So now I had this yellow tank. what to do? Well I had this kinda business where I bought neighborhood beaters cheap, fixed them and resold them to all my brothers myriad of friends.So I dug into it. I found every single valve had kissed the pistons. Can you imagine? Out came a pair of heads from the stash, and a few hours later we had a fine running teener. And lots of eager buyers. Well I figured a road test was in order. Well the first set of tracks I crossed and the car was headed for the ditch. I managed to save it and nursed it home, where I immediately put it up on jackstands for an inspection.What I found was rotten frame rails and rusted off inner fender aprons. Since I had no welding experience (this was about 1980) nor friends who did, this body was scrap metal. I stripped out the good stuff and made the call. Im sure I still have that motor around here somewhere too. Or maybe I put it into this old Demon I once had. Yeah I think thats where it went.
There might be a point here somewhere. I think Mopars take all kinds of abuse and shrug it off.If they keep all their fluids in the right places, theyre like the Eveready Bunny. Sorry to clutter up your thread. May the Force be with you.
Well I had this blown up 318 laying around, and now this fugly pistoned 340. Well now, you can guess the rest. One bank of pistons had pits the size of half-BBs.I spent some hours on it (hey I was still living at home and unemployed) And put that teener top end on that junkyard 340, with nothing more than a set of 340 springs, and dont you know that conglomeration ran gangbusters.Well at least in my mind.I think I might still have that beast around here somewhere.
Just reminiscing. I wonder if you arent worrying a bit overly.If youre gonna run 10/10ths, Stuff gets real important. For street motors not so much.
My brother told me a good story. Seems he and some rascally buddies were out bush-partying this one time and got a bit crazy. They had this beater 74 Duster that body-wise was done. Well they fired it up and bricked the gas pedal wide open. After about a half hour of that( not my story) they got tired of the screaming teener.Well one brave young boy figured out how to get it shut off. Well of course it didnt run after that so they gave it to me. So now I had this yellow tank. what to do? Well I had this kinda business where I bought neighborhood beaters cheap, fixed them and resold them to all my brothers myriad of friends.So I dug into it. I found every single valve had kissed the pistons. Can you imagine? Out came a pair of heads from the stash, and a few hours later we had a fine running teener. And lots of eager buyers. Well I figured a road test was in order. Well the first set of tracks I crossed and the car was headed for the ditch. I managed to save it and nursed it home, where I immediately put it up on jackstands for an inspection.What I found was rotten frame rails and rusted off inner fender aprons. Since I had no welding experience (this was about 1980) nor friends who did, this body was scrap metal. I stripped out the good stuff and made the call. Im sure I still have that motor around here somewhere too. Or maybe I put it into this old Demon I once had. Yeah I think thats where it went.
There might be a point here somewhere. I think Mopars take all kinds of abuse and shrug it off.If they keep all their fluids in the right places, theyre like the Eveready Bunny. Sorry to clutter up your thread. May the Force be with you.
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