✪ Alekshop 4.6L S65 Stroker - World's Highest HP NA Motor

[monkawekrue]

so sick

[Disturbed]

Nice build. Best of luck selling them as fast as you can build them! If my motor ever pops, I'm giving you a call for a "rebuild" ;-)

[bmwusa]

awesome build, what do these guys run price wise did I miss it? are these cheaper then the dinan options?

[Ofmalik]

Congrats Aleks, what a build! I follow your official profile on Motoroso and caught a sneak peak of this stuff there

Here it is for anyone else wanting to follow Aleks and his crazy builds and shoots: http://www.motoroso.com/alekshop

[MKE_M3]

Being honest, is there anyone who would not have preferred this motor in the F8x? U wouldn't imagine it's would cost much more than the base S65 if produced in the same volume by the factory, though emissions and gas mileage would obviously be a serious problem.

[ATH_M2]

That is awesome, good work!

[Hujan]

Originally Posted by MKE_M3

Being honest, is there anyone who would not have preferred this motor in the F8x? U wouldn't imagine it's would cost much more than the base S65 if produced in the same volume by the factory, though emissions and gas mileage would obviously be a serious problem.

Eh, maybe. They could have made the secondary cats 400 cpsi instead of 200. As for MPG, they could have made the 7th gear much taller on the DCT to boost highway MPG. Plus, the lighter weight would have improved MPG.

A lighter, stiffer, more torquey NA motor with a mild increase in MPG would have been an amazing F8x M3/M4.

[Dave07997S]

The issue for the fuel economy could have been greatly alleviated by the use of Direct Injection. Not to mention the potential for more horsepower. Look what Porsche is doing with their NA motors ala GT3.

Dave

[bradleyland]

Originally Posted by Hujan

Eh, maybe. They could have made the secondary cats 400 cpsi instead of 200. As for MPG, they could have made the 7th gear much taller on the DCT to boost highway MPG. Plus, the lighter weight would have improved MPG.

A lighter, stiffer, more torquey NA motor with a mild increase in MPG would have been an amazing F8x M3/M4.

The output RPM limitation of the Getract sourced transmission (DCT) won't allow for a taller overdrive.

[Sean@PSI]

Incredible, great info!! Love it all!

[Hujan]

Originally Posted by bradleyland

The output RPM limitation of the Getract sourced transmission (DCT) won't allow for a taller overdrive.

You're saying they couldn't keep every gear the same except fit a taller 7th gear so 75 mph would be 2500 RPM instead of 3000? Not sure I follow.

[IMG]

Originally Posted by Alekshop

Great!

Your LC build is up next ?

That's actually not a bad idea 😬

[bryan292009]

Alek,

What are your thoughts on adding these cams to a non stroked S65? I am looking at increasing power but don't want to go the SC route. Already running test pipes, Corsa axle back, under drive pulley, and Dinan intake! Thanks for any input!

[sales@ESSTuning]

One of my favorite cars

[warp10]

Originally Posted by bryan292009

Alek,

What are your thoughts on adding these cams to a non stroked S65? I am looking at increasing power but don't want to go the SC route. Already running test pipes, Corsa axle back, under drive pulley, and Dinan intake! Thanks for any input!

Would like to know this as well. Don't want to SC but would consider a cam upgrade. I know Schrick makes two different types.

[e46e92love]

Can someone explain to a novice on engine building:

1) why no one else used cams
2) why cams would take away from torque down low
3) why I am not successful enough to afford this to be done to my e92 this weekend.

Cheers,
e46e92

[Teeopi]

any updates for the sound clips?

[Ezio]

Originally Posted by e46e92love

Can someone explain to a novice on engine building:

1) why no one else used cams
2) why cams would take away from torque down low
3) why I am not successful enough to afford this to be done to my e92 this weekend.

Cheers,
e46e92

usually cams or a cam keeps the valves open longer, to get more fuel/air for more power. When the engine isnt spinning quick you have a slower cycle. you dont have a fast open close cycle.

I had a after market cam in my camaro. in the camaro we use a single cam, the M3 uses more than one cam.

[bradleyland]

Originally Posted by e46e92love

Can someone explain to a novice on engine building:

1) why no one else used cams
2) why cams would take away from torque down low
3) why I am not successful enough to afford this to be done to my e92 this weekend.

Cheers,
e46e92

EDIT: I typed this in a hurry, so if anyone notices any errors, please feel free to jump right in and correct me.

Engines are, essentially, air pumps. They burn an air/fuel mixture that must be very close to an optimal ratio, or they don't run well. Fuel is where the actual power is (thermodynamics, yo!), and because the engine must run at a fixed air/fuel ratio, if you want to burn more fuel, you'll need more air. A performance cam increases the size of the valve opening (lift), and the length of time that the valve is open (duration) during each rotation.

In a simple universe where everything worked without complication, we could simply go about our business increasing lift and duration until we had the power we want. Unfortunately, there are other dynamics at play. Air flows most efficiently above a certain velocity.

To understand how lift affect this, consider what happens when you blow air through a straw versus blowing air through a garden hose. A human can blow a pretty good jet of air through a straw, but through the garden hose, the air will move much slower.

The same problem occurs at low RPM when you have a large valve opening. The air moves through slowly, and sort of "stumbles" (it doesn't actually stumble, dur) its way in to the cylinder. This is an inefficient flow of air, which -- you guessed it -- causes a reduction in torque output at lower RPM.

Duration has similar negative effects at low RPM. With a high-duration cam, you'll have a lot of overlap between the intake and exhaust lobes. This literally means that your intake charge (fuel/air mix) can flow right out the exhaust while the overlap is active. At high RPM, the actual length of time that overlap occurs is small, and provides some advantages, because it creates an effect called scavenging. Air has inertia, just like any other object with mass. When you have valve overlap, the inertia of the existing exhaust charge creates a slight vacuum as the piston begins to move downward on the intake stroke. At low RPM, however, the velocity of air isn't high enough to create the scavenging effect, so the overlap has negative effects. Some of your intake charge can literally flow out of the exhaust port.

These negative effects are why an engine with a really aggressive cam must idle so high. An engine with aggressive cams will idle more roughly, and might not feel as fast when driven around town, because you never get in to the engine's higher-RPM power band. That's why many people prefer a supercharger. You can get an increase in power without giving up low-end torque. To the contrary, a SC improves torque output throughout the RPM range. The SC ends up being more practical. Not everyone cares about practical though. I'd take this stroker over an SC'd S65 any day of the week. Not for any objective reason, but because I love the character of naturally-aspirated engines.

[bradleyland]

You should also check out this link, you'll really like it if you're curious.

http://www.autozine.org/technical_sc...ine/Index.html

[e46e92love]

Most of the tech I basically understood, I guess what I was missing is not that you lose low end torque, but could lose low end smoothness and practicality.

That being said, I would rather lose that then have my engine go dead around 7k like other strokers and redline under 8k.

Thanks guys!!

Cheers,
e46e92

[AP3X_FTW]

We need a video of this beast! How have we gone this long without capturing it on film...?