Hey guys I've been cleaning up some factory 5.9 magnum pistons with oven cleaner. I've done in the past without any problems but this time I left them a bit long. the oven cleaner discoloured the pistons a little bit. if they coated pistons then I'll replace them but if they're not coated I'll use them. Does anyone know cheers
Are factory 360 Magnum pistons coated
- Thread starter maca
- Start date
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Stock OEM ,not that I have seen maca ..Speed Pro replacement, yes.
I thought that the stock Magnum Pistons were hypereutectic
They are.....
Wyrmrider
Well-Known Member
run em
if they are a little loose knurl the non thrust side
better get some oil on those pins
if they are a little loose knurl the non thrust side
better get some oil on those pins
I read that they are. Does that mean no coating?
pishta
I know I'm right....
none, coated are the ones with the black skirts....like these?
Is there a coating you can spray and bake on them?
pishta
I know I'm right....
Several, but they are thermal barrier coatings, not like the break in coatings that piston manufacturers use. Usually you use a TBC on the crown to keep heat in the chamber.
moper
Well-Known Member
I thought they had a skirt coating on them. But I wouldn't worry about it. Get some penetrating oil on the pins quick though.
Bobzilla
Well-Known Member
Hypereutectic is the process used to cast the piston. It has nothing to do with coatings.
I have not seen evidence of the factory installed pistons having any coatings, but never say never.
Most aftermarket hypereutectic pistons have the skirts coated, like shown in pishta's picture. The Mopar crate engines and short blocks that were Magnum based and were larger than 4" bore did have coatings.
Yours can be run as is, as long as your piston to bore clearance is not excessive (probably fine), and you make sure the round holes inside the ring grooves are not plugged up with carbon. If they are plugged, just clear them out carefully with a fine pointed pick.
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