Stan,
Thank you. Well said.
Guy
67.5 Stroker in progress
Tempe, AZ
Stan Chernoff wrote:
>Pistons made in China and expected to operate at 2000 rpm in engines with
>an 8:1, or lower, compression ratio are not necessarily designed for
>operation at 6000+ rpm with 10:1 compression ratios. There is more to
>consider than looks. Material selection, casting density and autothermic
>strut design along with other factors must be considered when making or
>selecting performance pistons. The Nissan flat top pistons made for the
>U-20 will take the kinds of stresses that will be generated by a stroker R
>type engine or the U type.
>
>People in the manufacturing business must be cost competitive and focus on
>the market that is buying their products and on the application. Good
>business people make products that meet their customers requirements but
>not exceed them to a ridiculous degree. Economies of scale are significant
>in product cost especially when the product design is focused on the end
>use requirements. Even Nissan designed components for their specific use.
>An example is the 3-main crankshaft for the H-19 engine since some were
>castings and some were steel forgings depending on their application. The
>steel forgings were made for the higher performance applications and can
>make a 3-main R engine into one with the same displacement as a U-20
>(Stroker). Compare an H-20 crank to a
>U-20 crank and you will see many differences that have an effect on their
>respective performance. You may also note that the U-20 has an harmonic
>balancer, that the R and H engines lack, that was not put there to waste
>money.
>
>Dished or recess top pistons are not performance oriented. Engine
>performance is somewhat proportionally related to compression ratio. The
>compression developed by flat top U-20 pistons in an R block with a U-20 or
>H-20 crankshaft is not excessive and affords much better performance than
>the lower compression dished forklift ones as long as the cylinder head is
>not cut excessively.
>
>My R engine with a U-20 crank, rods and pistons and a cyl head cut at least
>.100" made it to and from Shasta in the 110+ deg F temperatures without any
>cooling or pinging problems while using a 4 row high efficiency radiator
>core and the original 4 blade steel fan. It got a little over 20 mpg for
>fuel consumption with Solex carbs.
>
>If you are lucky you get what you pay for. Cheap isn't always the best.
>
>Stan
>========
>
>At 07:40 PM 8/27/02 -0400, you wrote:
>
>>For a good example of your theory see definition of Chevy Small Block.
>>Manley valves which cost me 20.50 are about $8 each. Pistons? Except for
>>forged or HP units are ridiculously cheap and made by respected
>>manufacturers.
>>
>>It makes me sick looking through a Summit catalog. Look at the prices of
>>Mopar or Ford engine parts and they cost more.
>>
>>BTW, the forklift parts are made for industrial use and are more often than
>>not, overbuilt for reliability. People use the equipment to make money can't
>>afford frequent breakdowns.
>>
>>Mike
>>
>
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