Sharp edges on JE pistons

[jimbauman]

The area of these JE pistons that the arrows point to is a very very sharp edge - a couple of mm above the top land at the edge of the indent. Should this be so sharp? The thin metal might create hot spots or even melt?



Should this be left alone or machined to a smoother edge?
JB

[kenikh]

It is standard practice to smooth these over. A light grit sandpaper works well.

[304065]

Jim,

I did exactly that, here are the pictures in my "Jugs and Slugs" thread.

http://forums.pelicanparts.com/showthread.php?t=368320&page=3&highlight=jugs+slugs

[jpnovak]

I did the same using a fine roloc scotch brite pad in my angle die-grinder. Provide a good radius there. You can also round over the sharp edge where the valve pocket hits the center of the piston crown. John has some great pictures in his thread.

[jimbauman]

Thanks for the replies - and those are some excellent pix in the slugs thread!
JB

[cgarr]

So what are you building??

[jimbauman]

..helping a friend rebuild a stock 3.2 into a 3.4. Old cylinders were alusils so he decided to upgrade rather than have them reworked.

JB

[cgarr]

Nice: Those looked a lot like the pistons I used in my 3.4 build: Going 10.5/1? twinplug?

[jimbauman]

Unfortunately not! :-( It has to remain smoggable for California emissions, so the only other mods he can really get away with are 964 cams, SSIs (replaceable at smog time), and a Wong chip.
JB