Boat tailed main webs

[Mick_D]

12 year old threads never die, they just get spicier.

[Mark Henry]

Originally Posted by Mick_D

12 year old threads never die, they just get spicier.

Dang....some anthropologist dug up an ancient thread and I fell for it

[chris_seven]

Originally Posted by Henry Schmidt

Gilroy was the garlic capital of California, the USA and maybe the world but almost 60% of the garlic sold in the US is grown in China.

Henry,

Have you tried 'Rose de Lautrec' Garlic from France or Aglio Rosso di Sulmona from Italy? I always used to buy these types when I travelled to Europe for work.

The bleached rubbish from China is poor and if Monsanto win the battle most garlic will be GM type.

Boat tailing has always interested me but I have never seen any test results.

In theory at least fluids moving in a streamlined manner don't like square corners and depending on their density and viscosity the turbulence generated can be significant.

The worst impact may be on oil temperature which could be difficult to translate into a parasitic loss that could be measured reliably on a dyno.

I would think that the 10% claimed would be quite easy to measure on a repeatable basis as we certainly achieved around 0.25% on a high speed water brake with in-line torque measurement.

Modern 4 - Quadrant 'motoring' dyno's of the type produced by AVL should manage this accuracy quite easily (https://www.avl.com/-/avl-dynospir-1) and even older designs with load cells and trunnion bearings should manage 1%.

I must say that I think 10% is very optimistic as the effect of this much windage on oil temperature would be huge and easily observable.

[afterburn 549]

I bet Smoky Yunick would have boat tailed .

[AlfonsoR]

OK, I'll bite..... Chris, where can i get this fancy garlic? I love the stuff.

[Henry Schmidt]

Originally Posted by chris_seven

Henry,

Have you tried 'Rose de Lautrec' Garlic from France or Aglio Rosso di Sulmona from Italy? I always used to buy these types when I travelled to Europe for work.

The bleached rubbish from China is poor and if Monsanto win the battle most garlic will be GM type.

Boat tailing has always interested me but I have never seen any test results.

In theory at least fluids moving in a streamlined manner don't like square corners and depending on their density and viscosity the turbulence generated can be significant.

The worst impact may be on oil temperature which could be difficult to translate into a parasitic loss that could be measured reliably on a dyno.

I would think that the 10% claimed would be quite easy to measure on a repeatable basis as we certainly achieved around 0.25% on a high speed water brake with in-line torque measurement.

Modern 4 - Quadrant 'motoring' dyno's of the type produced by AVL should manage this accuracy quite easily (https://www.avl.com/-/avl-dynospir-1) and even older designs with load cells and trunnion bearings should manage 1%.

I must say that I think 10% is very optimistic as the effect of this much windage on oil temperature would be huge and easily observable.

I would be interested in seeing your actual data on oil temp changes directly related to boat tailing a 911 case.
I wonder why Porsche factory in all their wisdom missed this aspect of case design.
I always thought that if their was any benefit to shaping the main webs that Porsche would have simply cast the case with a slight taper or curvature of the web instead of the flat surface we see in every engine. The early engines (sand cast aluminum ) had a slightly round main web but in later designs Porsche moved away from that feature.
Live and learn..