SVTeeshirt

Do you only need dished pistons with aftermarket cams?

Im staying stock cams for a while but do plan to go aftermarket blower cams down the road. My heads are staying stock besides springs and retainers... possibly valves.

Oh btw i bought an injen stand yesterday as my friend gave mine away

should be underway this week.

whats pricing like now a days on .020?

TheMustang

Dished pistons are meant to lower compression..depending on how huge of cams you get they might need flycut? Maybe somebody else will chime in.

TheMustang

And where i'm at the labor for boring a block out .020" is only $200 and another $200 to assemble the shortblock.

SVTeeshirt

i don't need any help assembling, i know dished pistons lower compression which is making me think i may need 18cc over 22cc, but i thought these would help avoid PTV contact as they are concave at the top. wouldn't flycutting also decrease compression?

Xemeth

Flycutting will decrease it, but less than a completely dished piston.

The 4v's don't use as much lift as the 2v's. I actually haven't seen many aftermarket 4v cams over .500" lift. Most are in the .475 range.

My cams are a custom grind, .478" lift I think, which is pretty huge for a 4v. However, I have stock 2v pistons, so they're dished and there's plenty of room.

You should be able to degree your cams to work with your stock pistons, however.

And as far as compression goes, they actually make high compression pistons that bubble at the top (like the opposite of a dish) with cutouts for the valves. The pistons you get should depend on what you're doing. Aren't you boosting it?

Oh, and why on earth would you want to replace the springs, retainers, and valves with stock heads and cams. You might as well at least port the heads if you're gonna have the valves out.

SVTeeshirt

yes im boosting, thus low compression, yeah i've seen domed pistons flycut, the reason im leaving stock cams and heads is $, i need valvesprings and retainers to throw alot of boost at it, we'll see how much $ i have when i have the heads apart... i'll do that part last.

edit: i was considering porting my heads myself but it seems risque with the 01 cobra heads, seems they are easy to mess up porting... "C heads feature a small exhaust port much like Ford’s earlier swirl port heads, but unlike in B heads, both the intake (throat region) and exhaust ports can see extensive porting work. However, removing too much material from the intake port (mouth region) of a tumble port head will kill velocity very quickly, so make sure your head porter knows what they are doing! "

Fobra

you dont want fly-cut with boost...

SVTeeshirt

care to elaborate? Dished better?

stock pistons fine with say stg 2.5 blower cams? there a year or 2 away but they will go in eventually.