sysopt

I was looking around at http://www.theoldone.com aka TOO and ran into this page:
http://www.theoldone.com/articles/en...pistons_1.html

He says just like one should remove the sharp edges from the cc, one should remove the edges from the piston as well. As you read on he claims on a boosted 340hp engine he tweaked out another 28hp from this modification alone (a little more than 8%, and in my opinion very significant). My question is why would one remove the egdes from anywhere inside the engine and how can one extract more power from it?

Thanks in advance (I'm new here, great web site, needs a few more people)

sysopt

Another question... Would this be worthwhile on a n/a application?

Grumpy

Sharp edges on a piston would tend to heat faster than the surrounding surfaces causing hot spots during the combustion process.

bps2799

While I'm not disputing the value of what you read at TOO, take some of what is said there with a grain of salt.
The guy has some credibility problems and may be exaggerating his claims.

raene

True.

On the other hand, if I get pistons from, say, Arias then I'm not going to go polish off the sharp edges if they're designed that way .

sysopt

Well removing the sharp edges would help prevent hot spots like grumpy said, and therefore possibly make the engine more detonation resistant. This might allow for more aggresive ignition timing and thus more power, yahoo! Does this theory make sense?

hybrid-t

what would you use to smooth the edges of the pistons?

bigTom

comments on edyn;

i dont believe anything he says anymore... and if i was you... i wouldnt either... if he made x amount of horsepower... show me a dyno graph... at least then it will be more believeable... anybody seen any graphs?

13secLSVTEC

I have also seen them talk about doing this in Super Street...they have more creditability...but again, no dyno to back it up....

92Si

I used to be "in awe", but I guess if you're making 350+ FWHP on an all motor B series and 400+ FWHP in daily driven supercharged applications, why don't we ever see any of these cars at the track? In theory yes, removing the sharp edges from pistons should reduce the number of "hot spots" and maybe in doing so you can also smooth the "bottom of the combustion chamber", but i'm not about to take a hand grinder to a piston (as Larry uses hand tools due to lack of MACHINE EQUIPEMENT @ his house) that I just paid a bunch of money for. Sorry about the ENDYN rant, but before I take advice or purchase pistons/rods whatever, I would like to see:

1. Shop Address & Credentials on Webpage
2. Showings WITH cars @ major race events
3. Real photographs of shop and dyno charts

Don't get me wrong, I still read the forums and will still consider purchasing a set of the Rollerwave pistons, but I'd like to know where my money is going.

vhd

use emery paper/crocus cloth to smooth out the sharp edges from the pistons(top only), even aftermarket pistons will have sharp edges that need to be removed

accordking

Rollerwave pistons have been around since the early 80's........It's nothing new.

blkDOHCsol

I dont want to get into the endyn ****..but if you think Larry is full of **** and want proof of his work, then look at his car..He has an old *** civic hatch running low 11's on street tires...my boy has got his head ported by endyn and his car screams...im a believer.

89civicdx

Smoothing out sharp edges around cylinder head combustion chambers and on piston tops is not really for the purpose of making more power but is a key step in a well built motor. The shap edges will get hot and glow like a spark plug causing the fuel/air mixture to pre-ignite (detonation) which is not good for your motor.These are very good steps to take especially if you are building a road race motor that will spend long races on the track as those motors will see more heat than a drag motor. Larry is not the only one who does this ,anyone who knows about building performance motors will perform this kind of work and its good sign of a experienced engine builder.

In the CC there are sharp edges around the valves and the CC wall closest to the valve, they are normally smoothed as well.

accordking

Did I ever say anything that mentioned Larry "is full of ****"? Quit thinking too hard. I mentioned that Rollerwave piston's have been around since the 80's.