Pros and Cons of grinding/polishing combustion chambers smooth?

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Bad Sport said:
That's pretty wild.
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It is wild. I've tried for many years to perfect it. I've spent several hours on the phone with Larry Meaux about it. Talked to Chad Speir too. Both really nice, smart, helpful guys.


I can't duplicate their pattern. Don't know why. So my stuff runs better with a paper roll finish.
 
I like to read Chad's post over on Speedtalk.com . I sure have learned a lot of the professionals that post there. Some VERY heavy theory too.
 
Bad Sport said:
That's pretty wild.
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I'd hate to have to do that manually on iron heads! Mostly done via cnc on aluminum heads... some guys claim 15-40 hp on a race engine.

I guess I would believe that a rough texture would keep the fuel mixed with the incoming air... I might rough up the intake side of my W2's before the next racing season.
 
Mopar-Man said:
I like to read Chad's post over on Speedtalk.com . I sure have learned a lot of the professionals that post there. Some VERY heavy theory too.
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Chad's a good guy to talk with... I think I will have him try to see what he can do with a set of Gen 3 heads when I'm ready.

Talk about 'theory'... I get lost pretty often over there. I guess those three years in 3rd grade didn't do much...
 
Just my opinion but i don't think I would mirror polish the combustion chamber and have proved that a mirror in the intake is a bad idea.
A mirror combustion chamber may be a good idea for detonation problem, but don't see any other advantage. Texture keep the air/fuel mixed in the port..............why wouldn't it do the same in the combustion chamber. I wouldn't polish up the combustion chamber any smoother than 80 grit on a cast iron head. here is a picture on top of a piston, that still make me go, Hmmm, was this machined????? or a nos created piston. Ask the owner of the piston but never got an answer. it was posted on facebook to show the crack on top to the piston.
12039272_1708361706043635_8290404600877522958_n.jpg

If that pIston was intentionally made that way, and i think it was..........why would you want a polished combustion chamber.!?
 
Cudafever said:
Just my opinion but i don't think I would mirror polish the combustion chamber and have proved that a mirror in the intake is a bad idea.
A mirror combustion chamber may be a good idea for detonation problem, but don't see any other advantage. Texture keep the air/fuel mixed in the port..............why wouldn't it do the same in the combustion chamber. I wouldn't polish up the combustion chamber any smoother than 80 grit on a cast iron head. here is a picture on top of a piston, that still make me go, Hmmm, was this machined????? or a nos created piston. Ask the owner of the piston but never got an answer. it was posted on facebook to show the crack on top to the piston.View attachment 1715122384
If that pIston was intentionally made that way, and i think it was..........why would you want a polished combustion chamber.!?
Click to expand...
-----------------hot spots!---- no wonder that piston cracked ! Surely that is a joke !
 
Sorry,
I kinda detored this thread with that piston.
 
Cudafever said:
Just my opinion but i don't think I would mirror polish the combustion chamber and have proved that a mirror in the intake is a bad idea.
A mirror combustion chamber may be a good idea for detonation problem, but don't see any other advantage. Texture keep the air/fuel mixed in the port..............why wouldn't it do the same in the combustion chamber. I wouldn't polish up the combustion chamber any smoother than 80 grit on a cast iron head. here is a picture on top of a piston, that still make me go, Hmmm, was this machined????? or a nos created piston. Ask the owner of the piston but never got an answer. it was posted on facebook to show the crack on top to the piston.View attachment 1715122384
If that pIston was intentionally made that way, and i think it was..........why would you want a polished combustion chamber.!?
Click to expand...
That image is the underside of a modified piston, maybe even a stock-type cast one at that. Why is anyone's guess, but weight reduction would be most likely, and it is way
too heavily relieved in a high heat/stress area. That has nothing to do with polished chamber surfaces. Breaking ALL sharp edges & polishing them some is std. op for Me on
just about anything I work on, that & getting rid of as many little "hidey pockets" that isolate the flame front, that is primarily what is needed to resist detonation. Polishing
the whole thing is for heat rejection and reduction in carbon which of course long term can help inhibit detonation as well.
 
Killer6 THANK YOU!!!!!!!!
That pic has bugged the crap out of me for over a year. Makes total sence, with that being the inside or under side of the piston.

You turned the light on. Thank you!
 
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