squish band

[Guest callithrix]

I know Harley sporsters have a reccomended squish band setting ( deck height) for pistons, but does anyone know if there is one for V11's? I'm getting ready to install my FBF pistons and would like to reduce any potential sources of pinging.

I know if I really wanted to eliminate potential pinging I woudn't install the pistons at all! But where is the fun in that

[Guest Fonzarelli]

Ideally, you want the minimum amount of squish possible without any mechanical interference. This applies to all internal combustion engines.

 

A zero deck is usually sought after for maximum performance and efficiency. The head gasket thickness will add a small amount of deck height to allow for rod stretch (very minimal) at higher RPM. It is also advisable to check your piston to valve clearance 20 degrees before through 20 degrees after TDC at overlap in 2-5 degree increments. This is where the piston is most likely to "kiss" the valves.

 

You will need a dial indicator and a degree wheel to check these specs.

 

While you have everthing apart, I would CC the heads and measure the crevice volumes to calculate a REAL static compression ratio. There are too many variables for FBF to call these 11:1 pistons.

 

Even with higher compression pistons, a minimum piston to head distance will actually LOWER your chance of detonation. The higher compression will run more efficiently with less timing.

 

 

I'd convert!

[emry]

Guzzi Tech

 

In other small bore low rpm

[Guest callithrix]

Thanks! Those parameters confirm my suspicions. They are almost identical to those prescribed for my Sportster ( safe ideal is 0.030") although I've heard of some sporty engines running as low as 0.025" with no adverse effects.Now all I need to find out is the crush measurement on the stock head and base gaskets.

Once I get the pistons installed I'm gonna get the engine broken in on the Dyno, see how that works.