Well, that arguement does make sense, but that is my recollection of the
info in the article I read. It was in the tech section of a R&T about 7
or 8 years ago.
Or perhaps, my OF memory has given up the ghost.
Larry
>>>>On 11/11/00 4:17 PM so and so (Ulix Goettsch) said. (And I quote:)
>I'm sorry Larry, but that can't be it. Just the volume in one combustion
>chamber is in the 20s of cc. Mine (increased a bit) are 24cc. On 4
>cylinders, that would add up to almost 100cc, not the 1.7cc that Toby is
>missing. My personal guess is that one of the stated numbers in his manual
>is incorrect.
>
>Ulix (currently about 1390cc + 100cc = almost a Big Healey :-)
> <hopefully back down to 1380cc soon :->
>
>on 11/11/00 11:21, Larry Macy at macy@bblmail.psycha.upenn.edu wrote:
>
>> Well his calculations are correct for the displacement/swept volume,
>> whatever.
>>
>> However, the capacity of the engine, here 1274.8, is not the same thing.
>> The capacity is measured as total volume, not the displacement.
>>
>> I used to think that was the right way too. I read a tech article a
>> couple years ago, where the exact same question was asked. Only on a
>> different engine. Where the calculated displacement was less than the
>> stated size.
>>
>> The answer is, that the manufactor states CC in total volume, not
>> displacement. If you do this calculation on any number of engines you
>> will find the same dicrepency.
>>
>> Larry
>>
>>>>> On 11/11/00 12:36 PM so and so (Guy Weller) said. (And I quote:)
>>
>>> But Larry, he is calculating swept volume.
>>> The volume of the combustion chamber, dished pistons and gasket
>>> thickness etc, will effect CR but not swept volume; shouldn't make any
>>> difference should it?
>>>
>>> ----- Original Message -----
>>> From: "Larry Macy" <macy@bblmail.psycha.upenn.edu>
>>> To: "Toby Atwater" <Toby@intri-plex.com>; "Spridgets@Autox. Team. Net
>>> (E-mail)" <spridgets@autox.team.net>
>>> Sent: 11 November 2000 04:18
>>> Subject: Re: British Pie!
>>>
>>>
>>>> You are also assuming that the head is exactly flat across the top
>>> of the
>>>> cylinder.
>>>>
>>>> It ain't.
>>>>
>>>> Larry
>>>>
>>>>> On 11/10/00 8:39 PM so and so (Toby Atwater) said. (And I
>>> quote:)
>>>>
>>>>> Hey, Im tripping over here.
>>>>>
>>>>> From Haynes & Workshop manual:
>>>>> "
>>>>> Bore 70.61mm
>>>>> Stroke 81.28mm
>>>>> Capacity: 1274.8 cc
>>>>> "
>>>>> everytime I calculate it I get 1273.1 ccs.
>>>>>
>>>>> Are the british using some kind of different Pi? (3.14159265358979)
>>>>>
>>>>> (Bore/2)squared X PI X stroke X 4 = displacement right?
>>>>>
>>>>>
>>>>> (70.61/2)=35.305
>>>>> 35.305 squared = 1246.443025
>>>>> 1246.443025 X PI = 3915.81625
>>>>> 3915.81625 X 82.28 = 318277.5448372
>>>>> 318277.5448372 X 4 = 1273110.17934
>>>>> 1273110.17934 /1000 (convert to cc) = 1273.1101793 !!!
>>>>>
>>>>> Dude... what am I doing wrong? am I incorrect in asuming that all 4
>>> cly are
>>>>> the same? or what?
>>>>>
>>>>> Thanks
>>>>>
>>>>> Toby
>>>>>
>>>>> trying to calculate his CR.
>>>>
>>>>
>>>> Larry Macy
>>>> 78 Midget
>>>>
>>>> Keep your top down and your chin up.
>>>>
>>>> Larry B. Macy, Ph.D.
>>>> macy@bblmail.psycha.upenn.edu
>>>> System Manager/Administrator
>>>> Neuropsychiatry Section
>>>> Department of Psychiatry
>>>> University of Pennsylvania
>>>> 3400 Spruce St. - 10 Gates
>>>> Philadelphia, PA 19104
>>>>
>>>> Ask a question and you're a fool for three minutes; do not ask a
>>>> question and you're a fool for the rest of your life.
>>
>>
>> Larry Macy
>> 78 Midget
>>
>> Keep your top down and your chin up.
>>
>> Larry B. Macy, Ph.D.
>> macy@bblmail.psycha.upenn.edu
>> System Manager/Administrator
>> Neuropsychiatry Section
>> Department of Psychiatry
>> University of Pennsylvania
>> 3400 Spruce St. - 10 Gates
>> Philadelphia, PA 19104
>>
>> Ask a question and you're a fool for three minutes; do not ask a
>> question and you're a fool for the rest of your life.
>>
>
> Ulix __/__,__ ___/__|\__
>..............................................(_o____o_)....<_O_____O_/...
>http://www.mirafiori.com/~ulix/ '67 Sprite '74 X1/9
>
Larry Macy
78 Midget
Keep your top down and your chin up.
Larry B. Macy, Ph.D.
macy@bblmail.psycha.upenn.edu
System Manager/Administrator
Neuropsychiatry Section
Department of Psychiatry
University of Pennsylvania
3400 Spruce St. - 10 Gates
Philadelphia, PA 19104
Ask a question and you're a fool for three minutes; do not ask a
question and you're a fool for the rest of your life.
|