Originally Posted by nick
I would love for you to elobrate a bit more on this cheap horsepower and piston design. You've hinted at it a couple of times in this thread but you keep leaving us hanging
I understand if you don't want to share though. Knowledge is a valuable thing.
On a side note to that, if cheap horse power an be design into pistons how come these aftermarket piston manufacturers design them into their pistons, thats the sort of thing that puts their product ahead of the competition
I would love for you to elobrate a bit more on this cheap horsepower and piston design. You've hinted at it a couple of times in this thread but you keep leaving us hanging
I understand if you don't want to share though. Knowledge is a valuable thing.
On a side note to that, if cheap horse power an be design into pistons how come these aftermarket piston manufacturers design them into their pistons, thats the sort of thing that puts their product ahead of the competition
Piston design is more than just you sending in your sr16ve piston and wanting it +4mm bore and 2.5mm higher piston pin with .100" deeper valve reliefs. There are a number of other factors that affect performance besides those. Weight is a major factor in high RPM power as well as longevity and engine wear. Now I am not going to give out all the secrets here ofcourse but most people do not know that you can make a 92mm piston lighter than a 84mm piston with the right design and "options" ofcourse. But most people do not know what all you can do to a piston when making "custom pistons". The average Joe just wants to spend as little as possible, sometimes not even considering how much power another few hundred $ could do for you, they would rather save $1 if they could. As piston speed increases, the engine moving components are acted on by friction as well as taking more power to continue to make the engine run while outputing "x" amount of power.
I have done 1 back to back comparison of piston design on power output. This was because someone got some "shelf" pistons that had 13:1 compression " stated" compression ratio and they were trying to run the motor on pump gas which didnt turn out too the best. The engine never blew up, it just didnt make the power on 92 octane as it was expected. The peak power was also around 8200rpm and it was thought to be more around 9000rpm. I was called upon to "spec out" a new set of pistons for them to replace their current ones. They bought some shelf stock CP's for $485 originally. The CP pistons that I got for them were $770, a $285 increase over their "shelf" ones. these pistons were spec'd for only 12:1 compression, and the whole piston was redesigned for weight savings where it could be. This motor is near 6000fpm at 9000rpm so any little weight you can save will help a lot.
When these pistons arrived (8 weeks later) the engine was removed from the vehicle and the block re-honed. Then pistons swapped over, and the engine was re assembled and installed. All in 1 day or so with 2 people working on it ( myself included). The next day it was broken in again and then retuned.
In the end, with 35psi less cranking pressure, this custom set of pistons made 7 more LB ft TQ and 24whp at 8800rpm. Some of this power gain was because of a better done design for better flame travel but most was the 269 gram new piston vs the 345 gram "shelf" piston. That is 75 grams in weight savings or about 22% lighter.
There are many options for piston design. Most of it you need to know the limitations of the motor itself, and the parts you are going to use. And as well, you need to know what your cylinder head can do and what its specs are, your combustion chamber as well as the valves and so on.
Next time you order pistons, ask a feq questions about your options.
The same goes for Connecting rods. Most people will put 600 gram Crower Pro series rods in a little 2.0L motor for NA use. Personally if you were going to do that, you better be spraying a nice healthy shot of Nitrous on it. Again, a custom con rod can weigh 25% less than a shelf rod, and yes it will probobly cost another 25% more too.
-Ted