2056 Build Options

[SteveNMaine]

I am trying to work out compression ratio of my 2056 build. In calculating head volume my understanding from the forum is that stock 2.0 heads have 57mm and the valve pockets on the pistons I am going to use is 3mm. Do I add these together to use 60mm in my calculations for head volume?

[technicalninja]

You should measure the valve depressions, head CCs and deck height yourself.

Don't EVER trust published data.

Now if the data came from Len Hoffman, LN engineering, or Raby I'd trust it...

Most published data shows the 2.0 head at 60cc and the 1.8 head at 55cc

I'd still check it.

What you need is a clear round piece of Lexan (Plexi-glass) approximately 105 mm in diameter (fits the cylinder register in the head) with two holes in it across the combustion chamber. One of the holes should be large enough to socket a 60cc veterinarian syringe in it and the other hole (completely across from the first but in the chamber depression) is an air bleed hole and can be very small.

A 60cc veterinarian syringe will work fine for anything below 10-1 but if you want to get "technical" a graduated burette is more accurate (and much bitcher to use)

You use a bit of grease/Vaseline to seal the edges of the plate to the flat surfaces in the head and then twist and turn until you can get all of the bubbles on of the air bleed hole. The placement of this hole is critical to reduce the bull shit you will encounter trying to remove the bubbles. I want the air bleed directly next to the edge of the chamber depression so I can tilt the head a little bit and have the critter bleed itself.

I'd LOVE to find a 70 or 80cc syringe but haven't been able too. 60s are super common. Burettes came in 100cc increments and work better with larger combustion chambers.

I'll sometimes use the 60cc syringe and then a 5 or 10cc syringe when I'm messing with things over 60 cc. Most combustion chambers are at 60 or below.

Use the plate directly on the piston to measure valve depression volume.
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