Taing it to the next level- 3.6 engine build

[Jake Raby]

Originally Posted by jaykay

Is this engine configuration only workable with a 3 - chain motor???

No, this can be done with any engine, 3 chain, or 5 chain. This particular engine has retained its 5 chain design.

I am currently building a 3 chain version of this thats based from a 3.8 997S engine. I am making that engine SMALLER to produce 100HP+ more than the factory rating.

While everyone else has been busy bragging about how big they can go, I was busy creating what will kick their asses. They never even knew it.

[Porsche9]

Originally Posted by Jake Raby

No, this can be done with any engine, 3 chain, or 5 chain. This particular engine has retained its 5 chain design.

I am currently building a 3 chain version of this thats based from a 3.8 997S engine. I am making that engine SMALLER to produce 100HP+ more than the factory rating.

While everyone else has been busy bragging about how big they can go, I was busy creating what will kick their asses. They never even knew it.

Smaller = stronger cylinder walls to handle the extra power/cylinder pressure and/or higher revs? Just curious. Sounds like we are talking about a 460 hp motor. Sweet!

[j.fro]

3.8 block destroked w/ 2.5 or 3.2 crank??? longer con rods w/ better rod angles?? Short stroke/big bore w/ improved combustion & spark timing?? higher CR??

[jaykay]

Originally Posted by Porsche9

Smaller = stronger cylinder walls to handle the extra power/cylinder pressure and/or higher revs? Just curious. Sounds like we are talking about a 460 hp motor. Sweet!

From the standpoint of straight mechanics I believe the larger diameter pistons give a greater potential for cylinder wall scuffing when coupled increased heat loads of the larger displacements. So you want to stroke it if you can......but in most cases that takes a much higher level of skill

[BYprodriver]

Originally Posted by jaykay

From the standpoint of straight mechanics I believe the larger diameter pistons give a greater potential for cylinder wall scuffing when coupled increased heat loads of the larger displacements. So you want to stroke it if you can......but in most cases that takes a much higher level of skill

Generally true about piston diameter, but longer stroke is problematic also. To minimize piston inertial cylinder loading you may need to increase connecting rod length. This also moves peak torque up the rpm range for higher horsepower peak.

I'm guessing Jake is building a shorter stroke, bigger bore engine to raise rpm level.

[The Radium King]

Originally Posted by jaykay

From the standpoint of straight mechanics I believe the larger diameter pistons give a greater potential for cylinder wall scuffing when coupled increased heat loads of the larger displacements. So you want to stroke it if you can......but in most cases that takes a much higher level of skill

pg 20 - fixed cyl height w longer stroke crank means shorter con rods which increases lateral loads on cyl walls. cyl wall scoring showed up on the 997 engines w the move to longer stroke. piston size not as much of a factor (note the variety of bores on the m96 engines, but bore scoring not typically a factor on these engines). of course, improved cyl liners seems to have fixed it all:

http://www.hartech.org/docs/buyers%20guide%20web%20format%20Jan%202012%20part% 205.pdf

[Jake Raby]

Its all in the combo. This combo has taken since 2007 to develop, and I've shared all about it that I am willing to.

Stroke, rod length, bore, valve sizes, port flow margins, CR, and every other dimension within the engine is altered in some way with this combo. None of these are OEM Porsche dimensions, to include the stroke.

"The bigger is better crowd is always the easiest to beat".