Omega (QED) Pistons

[SpeedModel]

Both QED (SKU: 105003) and Burton have Omega forged pistons for the Twink that look to be the same, but QED says they are 10.5 to 1 compression and Burton says they're standard Elan compression: 9.5 to 1.

It would be appreciated if anyone that has recently used these pistons to share their final compression ratio and chamber CC volume.

Eric

[2cams70]

They are exactly the same. If you look closely at the picture on the Burton website they even have "QED" stamped on the top of them!

[SpeedModel]

They are exactly the same. If you look closely at the picture on the Burton website they even have "QED" stamped on the top of them!

Therein lies the rub. They are the same piston but one seller says they’re 10.5 to 1 compression and the other says 9.5 to 1. Which is correct?

[2cams70]

Therein lies the rub. They are the same piston but one seller says they’re 10.5 to 1 compression and the other says 9.5 to 1. Which is correct?

There's no rub. The Omega pistons are based on the original standard Hepolite 21093 piston. Same crown shape. The CR in that case is determined mostly determined by the combustion chamber and not the piston crown - i.e neither of those figures may be correct for your engine if the head has been resurfaced !

It's exactly the same piston in any case. QED have probably quoted "standard" as the standard Sprint spec and Burton's 9.5:1 based on the "standard" non-Sprint spec. For a standard piston it's the cylinder head that mostly determines the CR.