Small hole in side of piston ?

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duster rege

duster rege

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Im doin 318 build got block back from shop putting stock pistons new rings back in get to n8 piston putting rings in noticed small hole inside of it inside piston looks like 2 little cast mark ciicles that is were hole is now im freaked if any other has hloe cant tell down in cylinder has any one seen this before i did not put it in im gonna pull all others to check for holes.
 
Are we talking about oil holes in the ring lands ? Or what part of the piston ? Also what brand and model # of piston may help.
 
This is not in the compression side of the piston, so tHere technically would be no problem. But 40 year old pistons - would you really trust that they wouldn't screw up your new rebuild? Go get a set of Keith Blacks.
 
yea that what i should do t just re ringed and installed all other pistons ill pull them all outi have lunati 701 eddy dual plane headers 600 carb had 302 heads done block done ready to get back on road ill look into other pistons thanxs!!!!!!!
 

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Better safe than sorry! Now you won't be worried about it every time you rev the engine!:blob::blob::blob:

Yes, use flat top pistons that are flush with the top of the block so you can use "normal" gas in it. Check for valve clearance too.
 
Get all new pistons or just get one to replace the bad one. If I was gonna reuse that piston on say a stock type daily driver I would drill the void out round so it would be less likely to develope stress cracks, if it hasn't already.
 
THanx gonna check mancini for kb flat tops take care 68gtxman better safe iys my first build i guess ill call machine shop ask about valve clearance he asked what cam i was using i told him lunati 701 cam lifters he said he would set heads up to there specs my stock ros ill be ok ddo i need machine work to get old pistons off rods?
 
Yes, better get the rods fitted, mounted and then balance the whole rotating assembly (which is a must for new pistons). Buy the lightest pistons (forged) that You can find.

A balance job will cost about $200 to $250.

To check valve to piston clearance, you must mount the heads on the block with head gaskets. Put clay on the top of the piston and slowly rotate it through one crank shaft circle. Stop if you feel any resistqnce and take the head off - this may mean you are already hitting the piston. Then take off the heads and measure the the thinnest squished part of the clay. Check the factory manual for minimum clearance and remember that valve float will make it easier for the valve to hit the piston at higher RPMs.
 
OMG--that hole has likely been there since new. It is a casting flaw-Run it unless you must have new pistons. JRob
 
I had to lighten a set of pistons and ended up drilling a few holes just like this. Getting 7g out of an AL piston is tough! That MP piston set weight was all over the place.
 
RAMM said:
OMG--that hole has likely been there since new. It is a casting flaw-Run it unless you must have new pistons. JRob
Click to expand...

I'm with you on this one. I don't see any big issue on just a deglaze and rering. looks like a pretty mild combo to me. New pistons can open a can of worms with what it looks like your doing.....If it was mine, i'd just run'um.
 
I don't know if its just my eyes playing tricks on me but it looks like there is a hairline crack coming from the hole and going up towards the ring land. Might be casting flash but why take chances. Melling makes a decent cast piston. (I used the melling 5.2 magnum pistons for a bit more compression)
 
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