Supertec SuperCrank

[Flieger]

Sorry, but I can't help myself.

Here's fuel for the fire

[Henry Schmidt]

Originally Posted by jpahemi

Henry:

Are the OEM 911 cranks considered inferior to this crank? My understanding is the 911 crank is one of the better cranks produced...in the production car category.

jp

Porsche is renowned for their design prowess. That said, the Porsche 911 crank is inferior because it uses a 40+ year old deign. The oiling system is inferior as are the fly weight shapes and materials used.
As far as production car parts are concerned, Porsche parts are generally higher quality than most.
I will say that if I could buy a 66mm 9 bolt Porsche crank for a reasonable price, I would. One problem with the 961 (66mm, 9 bolt)crank that is somewhat available is that they use shouldered bearing for their titanium rods and those bearing are unobtanium.

[Tippy]

Bad@$&nes bump.........WOW!

[racing97]

"Porsche is renowned for their design prowess. That said, the Porsche 911 crank is inferior because it uses a 40+ year old deign. The oiling system is inferior as are the fly weight shapes and materials used."
Henry your marketing is getting the best of you. You must know that the reason Dave uses the Chevy Oiling method is he can't duplicate the path the oil passages take in the Porsche crankshaft currently with his CNC equipment it would take 5 axis he has 3. He (David) is a remarkable craftsman and a valued Vendor but inferior hardly applies in regards to the approach taken by Porsche.
Regards
Buliwyf

[Tippy]

How did Porsche create the oil passages since 5-axis wasn't around?

[Henry Schmidt]

Originally Posted by racing97

"Porsche is renowned for their design prowess. That said, the Porsche 911 crank is inferior because it uses a 40+ year old deign. The oiling system is inferior as are the fly weight shapes and materials used."
Henry your marketing is getting the best of you. You must know that the reason Dave uses the Chevy Oiling method is he can't duplicate the path the oil passages take in the Porsche crankshaft currently with his CNC equipment it would take 5 axis he has 3. He (David) is a remarkable craftsman and a valued Vendor but inferior hardly applies in regards to the approach taken by Porsche.
Regards
Buliwyf

I guess we'll just have to agree to disagree. I believe the newer design is better as are the materials.
Better oiling, better torsional rigidity and lighter. We also offer stroke and rod combinations unavailable from Porsche production cranks. Inferior? I guess that depends on your needs and your level of acceptable compromise.

[racing97]

"How did Porsche create the oil passages since 5-axis wasn't around?"
Five Axis was done manually with Dividing Heads and Indexing tables all hand cranked
The manufacturer for Porsche is
Overview- Maschinenfabrik ALFING KESSLER GmbH
The closest Quote to duplicate the original oiling in a Billet crank here is Braynt or Wineberg the best we have in country@ $6,000 to & 7500 each for 10 cranks.
So Marine is cost effective and quite skilled and David is very accomplished and a Gentleman and provides a viable product by all means.
I have no bone to pick but take issue to premise that the very cranks in the current 991 are inferior is opinion.

[Tippy]

^ thanks for the info! Good stuff.

[Flashoir]

B-e-a-utiful piece of kit, Henry. I'm not interested in a debate about who's is best, but I sure would love to hear that 3.0 revving over 9,000!

[chris_seven]

Originally Posted by racing97

"How did Porsche create the oil passages since 5-axis wasn't around?"
Five Axis was done manually with Dividing Heads and Indexing tables all hand cranked
The manufacturer for Porsche is
Overview- Maschinenfabrik ALFING KESSLER GmbH
The closest Quote to duplicate the original oiling in a Billet crank here is Braynt or Wineberg the best we have in country@ $6,000 to & 7500 each for 10 cranks.
So Marine is cost effective and quite skilled and David is very accomplished and a Gentleman and provides a viable product by all means.
I have no bone to pick but take issue to premise that the very cranks in the current 991 are inferior is opinion.

I have to agree that in general to suggest that new components are 'better' than traditional components can be a moot point.

Four Cylinder Ford cranks are a perfect example - the standard cast iron cranks work very well and have excellent fatigue life even at high revs but we always replace them with expensive 'steel' components because they are better.

The reality is that they just don't fail so why spend the money.

Short stroke 911 Cranks with counterweights seem to be fairly bomb-proof and if we do some very basic analysis are a long way from their torsional resonance and unlikely to suffer from fatigue failure.

When we -recycle one of these cranks we do shot peen the fillet radii locally as this will help to remove any of the accumulated damage that can result in a longer term problem.

Material selection is always interesting and the basic steel used by Porsche does seem to have stood the test of time and provided a durable crank quite cost effectively.

Material cost when only making small batches is, of course, largely irrelevant as it is such a small proportion of the total.

Clearly when you are making a million parts it really does matter so it is quite normal practice to select the lowest cost material that gives the required result.

Using costly VAR materials such as Boehler V358 or one of the Nitrodur range is a good insurance policy if you don't plan to carry our any fatigue testing or detailed torsional analysis as it gives a 'new' design the best chance of survival.

If you have access to good software it may help to improve confidence in a basic design.

We used to work with software developed in Germany which always proved useful in ironing out design issues.

ARLA Maschinentechnik GmbH

[Henry Schmidt]

A few simple questions.
Do you believe (as I do) that a billet crank made from E4340AQ alloy steel (chromoly) offers superior performance (longevity and rigidity) when compared to production forged cranks?
Are the 66 or 70.4 mm stroke cranks 6 bolt as apposed to the 9 bolt crank used in the 991?
Is it possible to improve the oil flow characteristics on 911 cranks by cross drilling them?
Did Porsche redesign the 2.4/2.7 (6 bolt 70.4) crank for high performance applications because the original design offered poor torsional rigidity?
Is there an application for a 66mm crank not offered by Porsche in a production 9 bolt crank?
Are there design flaws in the 3.2/3.3/ 3.6 air cooled 74.4 & 76.4 that can be corrected by changing the oil flow characteristics and rod journal size?
Is it possible to improve the 2.0 crank for high performance application by reshaping flyweights and reducing the rod journal size?
If you answered yes to any of these questions, perhaps there is a need for a viable (perhaps superior) option.
I never said the factory 911 crank was bad. I am just suggesting that for some special applications, my crank is superior.

Of course. your mileage my vary.

[Tippy]

Seriously, hats off for the endeavor.

Mad respect.

[cmw]

All of our billet crankshafts utilize the factory oiling design