924Board.org

Joes924 · Guest

Thats right I was driven today getting parts together ... and it hit me hey,"Hey how bout I ask the porsche owners here if its a good idea to polish the top[piston] real good along with the under side of the head,real polishy".

"Best idea of the day award." I think.

dwak · Guest

I almost was going to say that's a tad anal but maybe not. Could be useful for seeing bad guys creeping up on you when you're working on the car. On the other hand, more primative Porsche owners may be drawn to the shiny objects and steal them.

924RACR · Posted: Thu Feb 21, 2002 8:57 am Post subject:

Wiseass.

I'd say not a bad idea, when you're running high compression or excessive boost; it'll help prevent detonation (I'd think) if done properly. Not worth it on a standard NA, though.

_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Joes924 · Guest

Ive heard that if you do it it might not work good cause its so smooth that theres no mixing of the combustant then I replied well
its fuel injected your thinking normally aspirated the reply was well then it might work I could see it working real good on the turbo but im using stock compression with a msd6 so is the injection atomized good enough to benefit from a polish job

924RACR · Posted: Thu Feb 21, 2002 12:41 pm Post subject:

I don't think you'll be running close enough to the edge to warrant it.

_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Joes924 · Guest

whats up vaughnn why you knocken my posts
[ This Message was edited by: Joes924 on 2002-02-21 15:16 ]

[ This Message was edited by: Joes924 on 2002-02-22 13:20 ]

924RACR · Posted: Thu Feb 21, 2002 2:21 pm Post subject:

I'm not saying you shouldn't do it, I'm just saying I think it'd be a waste of time and energy. Do what you want, it's your motor, and it's not likely to hurt anything, it doesn't bother me. I was simply trying to save you some wasted effort, but if you'd rather not listed to my opinion, you're more than welcome to ignore it. Personal abuse is quite unnecessary.

I apologize for the confusion on the redline post - I had meant that to be in this thread - I'll correct it. I run Redline myself in both street and race applications in the trans. You'll recall my initial posts in that topic were positive and supportive

_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Richard · Guest

May help delay carbon build-up on pistons. Then again, may not. My engine blueprinting book shows the piston tops all shiny, but does not mention in the text. Maybe they do it for the photographer!

924 turbo · Guest

This thread has me very, very confused.

924_fan · Guest

From what I've read, rather than polishing the top of the piston you would be better off having them coated.

Joes924 · Guest

I talked to another friend and he remembers the time he did his own port job and it was a v-8 any who he over did it and lost the hp instead of gaining it see so ya gotta watch it here ..

924RACR · Posted: Fri Feb 22, 2002 12:25 pm Post subject:

I've heard of that being a definite risk/issue with polishing ports and runners.

_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Richard · Guest

You got to understand that porting and polishing is part science and part black magic vodoo. What works for one engine may be a diaster for another. Race block preparation has a lot of trial and error and just like fashion there are trends that come and go. Use to be head ports were polished to a mirror finish. Then someone comes along and decides that a little roughness is better because the air and gas will swirl and mix better. Mechanics use to shave the edges of crank throws to a knife edge so they would cut through the oil/air mist in the sump in order to shave .000001 seconds off of their lap times. Would have probably been more effective to not eat such a big weiner at lunch and save a pound of extra gut-cargo. Joe, polishing your pistons is about 100 on a list of 100 things you could do to help performance. Would be better to balance the pistons and connecting rods to each other, balance the crank and flywheel. A smooth running balanced engine makes better h.p. because it is not wasting energy trying to shake itself apart.