milling a forged dome

[71chargerse]

im probably going with some trw forged pistons for my 440 build but i want to use the milled heads i have now on my 383 . the pistons are # 2295 and will be 10.3 compression with the stock head. i m thinking i could mill the domes to get my compression right. has any one done this and what do you think you could safely take off. a buddy at work says theres not enuff meat there to mill with out causing it to be too thin. i was under the impression that the dome is cast solid and not hollowwed out under neath . anyone have any experience douing this?

[John Kunkel]

Turn the piston upside down and see if the underside of the dome has a depression that corresponds to the location of the dome. If so, it's a hollow dome but it still might be pretty thick.

Using the bottom of the skirt as a reference, lay a straight edge across the bottom of the skirts and measure to the underside depression then measure outside from the skirt bottom to the top of the dome. Subtract the underside measurement from the outside measurement to get the dome thickness.

[ohioDemon]

you could try enlarging your chambers to lower your compression.
do you know what your comp. will be with current setup ??

[71chargerse]

thanks john and ohio d for responding, i dont have the pistons yet , so this is still up in the air. i dont want to buy them tho and find out they are way too hi a compression for street use. so i wouldnt be able to measure them before i buy. right now the 346 heads i have are 76cc. so that puts me up to 11.2 or so with these pistons.

[23T]

What about your head gaskets? but that may interfere wtih the quinch

[John Kunkel]

I've played with numbers on the 2295 piston and, with any combination, they just make too much compression for pump gas.
The 2355 is a better choice with stock chambers and the 2266 would probably work best with the milled heads.

[d.friction]

If you haven't bought the pistons don't worry. You don't need to run those 2295 domes in a 76cc head. Run a flat top the 2355 will give you around 10.25 and the 2266 will give you around 9.40. Plus you will get better flame travel.

[71chargerse]

thanks, ill probably go for the 2266s then.

[satelliteply65]

For what every it's worth, I bought the flat top 6 pack pistons. With 915 unmilled heads the comp measured 10.25.

After buying the pistons, many people told me that they are very heavy which made me to think that I should have done some more research. On the good side they said the weight would not hurt as long as I stay under 6500 RPM.

I be curious what some of the moparchat team thinks about the sixpack pistions.

[duetz]

The 2366 give you 8.66 compression with 88cc heads .The 2355 should give you 933 compression.Ihad a set of the 2366 in my 440.It was kind of a pooch at first.I milled the heads .060 and it woke it up big time.

[djswwg]

For what it's worth, if you haven't spent money on pistons yet, don't buy old technology FM pistons. Although they work ok, (I have them in my 440), they are way to heavy and cost more than other brands. At least in Canada! Do some homework. Figure out what compression height you need, then check out other manufacturers like Ross, Diamond, Probe,SRP, etc..........djs