What does "blue printed engine" mean?
Steve K. Lee
this and other forums. It seems like higher end car manufacturers
"blue print" their engines. Can someone kindly explain to me what
this means? Thanks.
Don Dixon
news:pomacvod5fuotncok...@4ax.com...
On the blueprints (engineering drawings) for any machined part, you see size
specifications like:
4.00" +/- .05"
or
12.03mm +/-.005mm
The +/- are tolerance allowances, meaning the part can be 4 inches plus or
minus .05 inches. This allows for normal variations in the machining
process.
What blueprinting does is to reduce this variation as much as possible.
This reduction in variation applies to both size and weight. The idea is to
match all components as closely as possible with the designers "ideal" part.
This gets you closer to the designers "ideal" engine. The benefits? More
power, better economy and a smoother engine. Normally, the engines rotating
parts are also balanced to a much tighter tolerance at the same time, which
allows the engine's redline to be increased. This is why you hear racers
referring to their engines as "balanced and blueprinted".
Why don't manufactures do this in the first place? Cost. With less
variation allowed, more parts head for the scrap bin or back to be
remachined. Some manufactures have done the B&B on factory engines (as
limited editions), as Chevy did for some Camaros used as the basis for their
specs for a "stock" engine for racing purposes. They built the CRT engines
by going up and down the assembly line, finding matched sets of parts (after
all, some parts would end up being "exact", just by the law of averages).
HTH,
Don
JXStern
wrote:
>The +/- are tolerance allowances, meaning the part can be 4 inches plus or
>minus .05 inches. This allows for normal variations in the machining
>process.
>
>What blueprinting does is to reduce this variation as much as possible.
This was a big deal in the 1960s, when manufacturing tolerances were
huge. Does anybody do it with modern products?
J.
Steve K. Lee
wrote:
>"Steve K. Lee" <plz_ask@if_needed.com> wrote in message
Great info, thanks!
Steve K. Lee
wrote:
Someone told me that Porsche does this and plus the higher end BMW and
MB cars, but don't quote me on that.
JXStern
wrote:
>Someone told me that Porsche does this and plus the higher end BMW and
>MB cars, but don't quote me on that.
They do it in the manufacturing process?
I ask, cuz it used to be something that was done in the field, after
you bought a car off the lot -- if I ever understood it correctly.
I'm not sure how you would distinguish this from standard quality
control and manufacturing tolerances at the same level, maybe 100%
testing instead of statistical?
J.
Steve K. Lee
wrote:
Sorry, I honetsly have no idea. After having read at various sites
and forums, those were some of the manufacturer names that were
included when blue printed engine talk came up.
Bill Freeman
(i.e. total quality management) methods advocated by the late American Dr.
W. Edward Deming (Juran, et al). These manufacturing methods advocated a
virtual "zero" tolerance for fit and finish .. . instead of the + or -
larger tolerances of American standards. Ironically, the tighter
"California" emissions standards ( plus Japanese competition) forced
American manufacturers to adopt many of Deming's methods de facto. Blue
printing is still used by racers the world over.
Bill
"Steve K. Lee" <plz_ask@if_needed.com> wrote in message
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-dave diego
soon...
Every manufacturing process has tolerances. It has to. Asking a machinist to
mill you
something with a diameter of 8.03" is entirely different than 8.0300", even
though the dimension
is the same. The decimals indicate the tolerance. the more decimal places,
the angrier
he gets.
TQM refers to quality at every level, not just higher quality at the
manufacturing level.
With CNC equipment and the accuracy of todays' heavy equipment, you can now
mill
an engine block to tighter tolerances than every conceived, and now we can
use thinner
oils and get better performance.
Don't mean to split hairs, but I've already had those angry machinists in my
yard. It wasn't
pretty.
-dave diego
"Bill Freeman" <bf...@netzero.net> wrote in message
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Bill Freeman
Ha, ha, ha .. . will try to find greater tolerance machinists!
Modern Japanese assembly line "zero" tolerances are achieved by computer
controlled processes (e.g. "transfer machines" .. . invented by Renault)
checked by QC people at each stage of the process .. . not just by "random"
checks or by large tolerance acceptance. See >> http://caes.mit.edu/deming/
or http://www.gslis.utexas.edu/~rpollock/tqm.html . The idea is that it is
ultimately cheaper to reject off-scale quality than to have to
replace/repair same in the field (or have a product fail outright -
milspec). Computerization and laser measurement are two big instances of
improvement .. .
Bill
"-dave diego" <dli...@san.rr.com> wrote in message
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