Fwd: [Harp-L] Double Reed Plate Harmonicas

[Joseph Leone <3n037@xxxxxxxxxxx>]

> 
> Vern, if you bore out cylinders and DON"T increase the stroke ..to make up for the enlarged VOLUME, the compression ratio will go DOWN not up.  
> 
> Ok, You have a 4" bore and a 4" stroke and the cylinder has a volume of 25.132736 cubic inches with a compression ratio of 10 to one
> In other words the cylinder head space is 2.513736 cubic inches when the fuel detonates. 
> 
> So, you increase the bore to 4 1/16" and STAY with a stroke of 4". You now have a volume of 25.525434 cubic inches in the cylinder
> and with that figure your compression is NOW 9.846154 to one. And 9.84...is lower than 10. 
> 
> So, to keep the compression at 10 you would have to INCREASE the stroke in order to DECREASE the cylinder's HEAD volume at time of detonation.
> ( Btw, This is usually done with offset bushings on the big end of the piston.)(Btw, milling the piston to clear the valves is sometimes necessary) :)  
> 
> Conclusion: Giving something greater volume does NOT increase compression. I find your formula faulty.  
> 
> Love ya hero...... Jo-zeppi
> 
> On Apr 10, 2016, at 4:26 AM, Vern wrote:
> 
>> Joe,
>> 
>> I’m with Halchak on this one.
>> 
>> Let P =  volume swept by the moving Piston. 
>>     H =  Head volume at the top of the stroke.
>>     R = compression Ratio.
>> 
>> (H + P) is the  total volume at the bottom of the stroke
>> R = vol at bottom of stroke / vol at top of stroke,  or  R = (H + P) / H
>> If P is bored larger, then R is also larger….assuming that you don’t mess with the head volume H.
>> 
>> Vern
>> 
>> 
>>> On Apr 9, 2016, at 6:12 PM, Joseph Leone <3n037@xxxxxxxxxxx> wrote:
>>> 
>>> 
>>> 
>>> Begin forwarded message:
>>> 
>>>> From: Joseph Leone <3n037@xxxxxxxxxxx>
>>>> Date: April 9, 2016 9:11:31 PM EDT
>>>> To: Vern <jevern@xxxxxxx>
>>>> Subject: Re: [Harp-L] Double Reed Plate Harmonicas
>>>> 
>>>> 
>>>> 
>>>>> 
>>>>>> ….If you bore out the cylinders on an engine to make them larger, it increases the displacement and raises compression.
>>>> 
>>>> If you bore out a cylinder and make the volume of the cylinder larger, you reduce the compression. 
>>>> 
>>>> smo-joe
>>> 
>> 
>> 
>