another piston ring question

[1930artdeco]

Hi all,

I am thinking of installing EGGE pistons in this next rebuild. Should I go with the original thick rings or the newer thin rings?

Mike

 

[Aerocraft]

In the past three years, I have overhauled two of my "drivers" engines. In both cases, I used Egge's pistons that feature the thinner, small block, rings. In both cases the engines broke in quickly and the oil has stayed cleaner between changes than with the original 1/8" rings. Hopefully, that means less cylinder wear. I have 5 K miles on the Coupe engine and 3.5K on the Roadster. As a sidebar, I switched to Rich Falluca's inserted rods at the same time. With the balanced pistons and rods, both engines are smoother than before the overhaul. Gar Williams

 

[Jim Brierley]

Definitely use the thin rings as they will seal better, thus less blow-by and probably less leakage.

 

[Special Coupe Frank]

You will probably see increased bore wear, as a result of increased pressure at the point of contact between the ring & cylinder wall, due to the decreased surface area of the narrower ring.

Maybe not enough to be an isuue...

Are the Egge pistons cast or forged ?

 

[Dave in MN]

My two cents on the rings

I suggest the thin rings....I have 49,000+ miles on mine and like Aerocraft states, the oil remains clear for most of the oil change interval.
Good Day!
Dave in MN

 

[Flathead]

Is it because they are thin? Or because they may be better quality, molly top ring for example. I don't see why a thinner ring would necessarily benefit a low compression, low RPM engine like the Model A.

 

[MikeK]

You will probably see increased bore wear, as a result of increased pressure at the point of contact between the ring & cylinder wall, due to the decreased surface area of the narrower ring.

Maybe not enough to be an isuue...

Are the Egge pistons cast or forged ?

Egge pistons are cast, which is a major advantage. Forged aluminum has a much greater coefficient of expansion and requires more cold clearance. The result is an engine that will rattle a lot from piston rock until hot. Forged pistons are also significantly heavier than the same style cast piston.

The picture below compares the Egge "A" pistons with narrow (modern) ring grooves with 283 SBC pistons which I am running in one of my A's. The full-skirt Egge Model A style pistons are over 100g heavier. Out of the box they were all within a 1.5g range. Superior machine work. The SBC pistons had a 10g spread and I had to take some off the skirts to weight match them. Very good machine work, but more unfinished than the Egge pistons.

Below are the longer press-pin insert rods (AER, Rich Falluca) for SBC pistons.
You need to heat the small end to about 400F, then press in the ice cold pins.
The inserts are drilled for dipper oiling.