notched pistons questions

[green]

hey, hows it going, i have a 1985 mustang gt 302 h.o roller engine, im thinking on new heads (edelbrock performer) but i had my engine rebuilt a few years ago and the builder put in just flat tops with no valve relifs. i know my engine did come with forged notched pistons but i dont know what specs are on them.

how many cc's cut into the piston do u use on a set of aluminum heads? also my engine is now a 306ci, so now i need to know a whole bunch of things. like how many mm is a .30over piston? also what is the bore and stroke of my engine now? feel free to add to these questions cause im totally lost when it comes to this. thanks alot.

 

[88mouse]

3inch stroke and a 4.030 bore not sure what it is in mm. Are you sure that the pistons aren't notched? Don't see to many aftermarket piston that aren't. Probably not going to have enough relifs for the 2.02 that the heads are going to have anyway.

 

[green]

so the 3 inch stroke would stay the same no matter what u did to the engine with the stock crank and rods?

is the the stock (standard) bore of a 5.0, 4.030?

with my 5.0 bored .30 over, would the bore be larger than 4.030?

nope, pistons are just flat tops, no valve relifs in them.

the heads are 1.90 / 1.60 valves.

also wondering is why ford put in valve relif pistons because i guess there not needed cause the engine builder put in just plain flat tops, and put in a bigger cam (dont know the specs) and did a 3 angle valve job to the heads. thanks alot.

 

[BlownFiveLiter]

The stock standard bore is 4.00 inches. The factory 85 HO pistons were flat tops, so it's possible that the engine builder used a stock style piston for the year, which didn't have valve reliefs.

 

[88mouse]

Need to find out what cam is in it. If its much bigger than stock i don't see how the valves aren't hiting the pistons. Because a 1.90 intake valve is the biggest that you can run on an ho motor. Yeah the standard bore is 4.000 and yours is now 4.030 boreing it didn't change the stroke.