alyak
Active Member
Can anybody tell me if these are performance pistons in my 360? Or how can I tell? Do I have to remove them?
Mopar 360 piston identification
- Thread starter alyak
- Start date
-
Nope. Stock style dished pistons. They COULD be old forged TRW or Sealed power. Even so, stock style and compression. Scrape all that crap off and there may possibly be a part number on top.
Projectile Dart
Well-Known Member
I opened up a spare 360 I have to see what was inside a couple weeks ago. I confirmed it has stock bore size and stock stroke. Everything else on the motor has been bone stock so I can only assume these are stock pistons. Mine seem to be sitting a little in the hole just like yours are. Your pistons look slightly different with the locating hole in the middle but otherwise look like stock replacement pistons to my eye.
Take a wire wheel or brush (carefully) to the top of the piston to see if it has any numbers on it
Take a wire wheel or brush (carefully) to the top of the piston to see if it has any numbers on it
alyak
Active Member
Thank you, I will clean them off and see if I get a number
Brake clean and a scrub brush! Work wonders. I also use WD-40 to help collect the crud up with some shop towels. The oil helps the crud to stick together and on the walls for the towel to sweep up. Just keep rotating the assembly around to get it all out.
Those pistons posted by the OP do have the lathe center center point in the crown like the aftermarket forged stock replacement pistons. If they are, they’re a really good strong piston for boost or nitrous use with usually at least .300 crown thickness. Also thick enough to safely mill for at least a 3.79 inch stroke and valve reliefs as well.
alyak
Active Member
If they are aftermarket forged will the engine be the same compression? I am guessing so since you said stock replacement. Also, do I have to remove the cam to be able to tell if it is aftermarket or stock?
alyak
Active Member
I’ll scrape them off after work today and post my findings here
Projectile Dart
Well-Known Member
We can only guess from pictures. If you want to know your compression for sure is to measure what you have. These engines are old and have likely gone through many owners in the years. If they are aftermarket pistons then it's possible they sit a little higher to get more compression. It's also possible that they sit at the same height as stock pistons but the block deck was milled down some. The only way to know for sure is to measure exactly what you have, at least to get a rough estimate. You can use a tape measure your stroke to determine stock stroke (3.58") vs stroker kit (typically 4.00")
You should use calipers to confirm the rest such as bore and how far it sits in the hole at the top of the stroke.
If you plan on taking to a machine shop they can do all this for you.
You should use calipers to confirm the rest such as bore and how far it sits in the hole at the top of the stroke.
If you plan on taking to a machine shop they can do all this for you.
READ my response above. If they are forged, they are stock replacement. I don't know what's unclear.
This is what I’m expecting you’ll find stamped on top. Stock replacement forging.
L2405F .030 OVER TRW FORGED PISTON SINGLE 360 CHRYSLER | eBay
As far as camshaft goes, measure the lift with a dial indicator from the top of the lifter without the pushrod in place and report back. Keep in mind that the lobe arrangement front to rear is Exh. Exh. Int. Int. Int. Int. Exh. Exh. Exh. Exh. Int. Int. Int. Int. Exh. Exh. when positioning the indicator.
L2405F .030 OVER TRW FORGED PISTON SINGLE 360 CHRYSLER | eBay
As far as camshaft goes, measure the lift with a dial indicator from the top of the lifter without the pushrod in place and report back. Keep in mind that the lobe arrangement front to rear is Exh. Exh. Int. Int. Int. Int. Exh. Exh. Exh. Exh. Int. Int. Int. Int. Exh. Exh. when positioning the indicator.
alyak
Active Member
Ok, you are right. That’s exactly what is stamped on them. They are TRW forged .030 over
If you’re up for it, the best way to I.D. the cam is with a dial indicator and a degree wheel. I would expect an engine with pistons that old to have a grind in it that either hasn’t been produced in some time or has an out dated part number on it. Oftentimes, the only way to identify it is to get a cam degree wheel and degree out the opening and closing events at .006 and .050. The lifter bank angle in an LA can be difficult to set an indicator up on to read the actual lifter body perpendicular to the lifter bore can be difficult, but setup works fairly well.
Clamping Dial Indicator
Clamping Dial Indicator
Stock replacement forged. Those are nice. They are heavy compared to what's available today, but they are darn near indestructible. I'd clean them up and run hell out of them unless the block needs boring.
And if the block does need bored but the pistons aren’t scuffed up or badly worn, it’s usually not hard to find a buyer for them, either.
Unless it had .010" wear, I'd get file fit rings and run it anyway. It'll rev like a ***** in church.
Absolutely!
They gotta be swappin holes before I'll bore it. LOL
-
