Best piston choice for Vortec Bowtie heads

[clark]

I am looking into running the vortec bowtie heads. What is the best piston choice for these heads to keep the compression up? Or do we need to just have the head cut to smaller chambers?

Thanks

[stockcar5]

I am looking into running the vortec bowtie heads. What is the best piston choice for these heads to keep the compression up? Or do we need to just have the head cut to smaller chambers?

Thanks

i run a standard flat top piston. i had mine welded and milled to 47cc. if you go with a dome to do it right you will need a custom dome. i like the flat top option better.

[fast_crew]

What size engine you running and how much compression do you want? I have read that there are a few 18* style pistons that fit the chamber with alittle modification, and Icon I believe may have made a piston to fit. Other wise a nice -5cc 2vr flat top, .035" piston to head clearance, and if need be send the heads to Brezinski for an Angle mill and chamber welding.

[dynoman14]

I personally use a complete flat top with custom eyebrows in them for valve size and angle, as well as valve clearance.
Josh is right about 18* stuff, although the dish stuff takes away from the CR but still makes great power. You need to make sure the fuel you are running with the engine combination has the right distillation and burn curve to make power with your engine.
Swirl port heads don't need much timing to light the charge and therefore like some specific fuel conditions to make good power.
I don't weld on the head to get the cc's down, I re-locate intake seats to allow additioianl angle milling to about 35-40ccs. I don't use a real big valve on the intake as the port does not need it to flow close to 300 cfms. The seat re-location and angle milling improve port entry angle quite a bit. I also reposition the spark plug hole and run a smaller diameter iridium NGK plug. I have some cast iron threaded plug sleeves made the can be milled into without a problem. I also think the small runner heads will make more power than the big runner for 358 engines. If you are running larger inch I would go with the big runner.
I have used a number of stock steel vortecs to make good power on Sportsman and Limited engines in the 500HP range.

[stockcar5]

Clark,
just some fyi so dynoman doesnt get you confused, the chamber DOES NOT need to be welded on the vortec bowties to get the chamber way down. what needs to be welded is the spark plug cooling passage. the area there is about 1/2 as thin as the deck and by the time you are done milling there will be nothing left to hold the head gasket.

[StuckInReverse]

I re-locate intake seats to allow additioianl angle milling

Do what???

[perfconn]

Dumba$$ way of saying he sinks the intake valve.

[Egoracing]

Dumba$$ way of saying he sinks the intake valve.

Nothing like hurting flow to raise compression!