What is the cubic inch displacement?

[Pat's 52]

What is the cubic inch displacement of an 8BA block with a 4" stroke and .060 bore increase? Thank you, Pat

 

[Ross F-1]

Approximately 261.8

 

[Kahuna]

264.92 ci, I think

 

[Ross F-1]

Oops, I skipped a line in the chart, 265.1, close enough to Kahuna's. Sorry!

 

[scrapiron]

BORE X BORE X STROKE X .7854 x How many holes

 

[Elmo Rodge]

I came up with 265.057 but I'm funny like that. Wayno

 

[bobH]

Elmo has it... pi/4 x D x D x S x #
265 +

 

[Kahuna]

It's Pi R squared X H X 8
It's 264.92
SO there

 

[bobH]

It's Pi R squared X H X 8
It's 264.92
SO there

3.14159 x (3 3/16+.060) sqd ÷ 4 x 4.000 x 8 = 265.0567, according to my cheapo calculator

 

[Mart]

265.090697

based on bore = 3.2475
pi = 3.142 (commonly used value)

workings:
Std Bore = 3.1875
+.060 = 3.2475
bore / 2 = 1.62375
1.62375 * 1.62375 = 2.636564062
*3.142 = 8.284084283
*4 = 33.13633713
*8 = 265.090697

Using the pi button on the calculator the answer comes out to 265.0563292.

Call it 265.1 or 265 for easy reference.

Mart.

 

[bobH]

265.090697

based on bore = 3.2475
pi = 3.142 (commonly used value)

workings:
Std Bore = 3.1875
+.060 = 3.2475
bore / 2 = 1.62375
1.62375 * 1.62375 = 2.636564062
*3.142 = 8.284084283
*4 = 33.13633713
*8 = 265.090697

Using the pi button on the calculator the answer comes out to 265.0563292.

Call it 265.1 or 265 for easy reference.

Mart.

It all comes down to abiding by the 'rules' for significant digits. All the input numbers are exact, except for pi. Mart used the pi button, which provides 'boo-coo' significant digits, so he can quote the result shown, with 10 (or whatever) significant digits.
If a person uses 3.14 for pi, then the calculated result can only have 3 significant digits. Any digits quoted beyond 3 are useless irrelevant nonsense. All of the above results round off to 265 for 3 significant digits, or 265.1, for 4 significant digits.

 

[Kahuna]

I'm with BobH

 

[r_reed]

since people state them to the nearest cubic inch anyway, let's just call it 265 and call it a day. i have a 0.60 overbore with a 4" crank, also. i did the calc a long time ago and got 265 as well. i have to remember not to say 239 or 255, keep those cubes up. dick r.