454 Piston Questions

[Bow Tie Omega]

I am in the process of puting back together my 454. The pistons are flat tops that were in good shape so I did not replace. My question is this:
There is a hole on the top of each piston, unlike the manual or BBC books state, the holes can go to the top or bottom rather then front or back. Do I point them to the top or bottom. Any help would be appreciated...Joe

[West Coast Dave]

I assume you are talking about the valve relief pockets that are cast into the piston. You do have two per piston for intake and exhaust. Is this correct for your piston????

[Bow Tie Omega]

No, this is not a valve relief pocket. It is a single drilled out hole about 3/16 in diameter on each piston. When the piston is placed with the connecting rod, it can only be placed pointing up or down. According to the manual, their is a single hole on each piston, but they should be pointing forward or back. This is my dilemma, the hole is on the outer top edge of each piston.
[ March 19, 2003, 03:02 PM: Message edited by: Bow Tie Omega ]

[gnarley]

The marks ALLWAYS point forward. These are or should be alignment marks that aid in determining what is top or bottom. They should also coincide with how the connecting rods are hung on the pistons so the bearing tangs all line up to the center of the engine if I remember correctly. If I’m wrong the correction is appreciated.
[ March 19, 2003, 03:19 PM: Message edited by: gnarley ]

[Fiat48]

Holes?

[gnarley]

I think he really means dimples

[Bow Tie Omega]

[ March 19, 2003, 04:22 PM: Message edited by: Bow Tie Omega ]

[shirkey4750]

Just tore down a friends motor, and all the holes were to the bottom or to the outside of the block. First time I had seen this type pioston.

[Bow Tie Omega]

Thanks shirkey. I am having problems posting pics, but I posted the pic on www.havasubarney.com (http://www.havasubarney.com) in the forums in Big Block Performance if anyone cares to take a look and chime in. Thanks..Joe

[wsm9808]

The holes,dimples,marks, or whatever you want to call them go UP, that means, to the lifter valley side. GM used the holes, but several aftermarket pistons that dont have a "front mark" have the word UP inside of an arroww pointing up(at the lifter valley)
[ March 19, 2003, 06:23 PM: Message edited by: wsm9808 ]

[Bow Tie Omega]

Thanks for the heads up all. Infomaniac also posted on Havasu Barney's Site. He also said up. I will give it a shot...Joe

[Oldsquirt]

Here you go BTO
http://www.havasubarney.com/iB_html/uploads/post-25-19977-Piston.JPG

[Bow Tie Omega]

Thanks Oldsquirt, there are 5 stars coming your way wink

[powerplay230]

Ok fact is I like big blocks but don't know very much... What the heck are those holes for, and how deep do they go???? jawdrop

[Eric455]

i dont know a whole lote about them either but i would think that those holes are to lower comression. i'm about 80% sure that i'm wrong but what els would it be their for. lol....
eric"always F^%ked in the head"455
lolll