Pros and Cons of grinding/polishing combustion chambers smooth?

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dibbons

dibbons

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I will be using factory open chamber heads on some street build 340's that will see occasional drag strip time trials.
 
MoparMike1974 said:
I would imagine it cuts back on carbon buildup too.
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I doubt if you see any measureable gains, but it should not hurt anything either, would be best to cc each chamber afterwards to verify they are all still in the size range that you desire once your smoothing and polishing is complete.
 
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I cannot think of any cons.......other than the time and work involved.
 
IMG_20171202_201607.jpg
like this?
 
It is time consuming to do a nice job---con.
It does retard how quickly carbon will build up in there, but it will build up eventually anyhow, smooth in form comparatively tho'---pro that diminishes with time.
Heat rejection is improved, but the amount is debatable & the effect degrades with the inevitable progression of the above---pro that diminishes with time.
The next time You've got 'er torn down, they'll clean up a lot easier---pro
You won't be removing more than 1-2cc's at most just doing that unless You start relieving the chambers on purpose, and there's really none on a smallblock to do,
so I wouldn't anticipate a problem with the squeeze. I have seen BB 906's (more than a couple) that have the chambers that represent cyl's 3&6 cast ~.025" shallow
compared to the rest,..that is an issue, and I've corrected them.
 
I can't take credit.... That goes to Ryan at Shady Dell. And he did an amazing job on the portwork! Very consistant from port to port.
IMG_20171202_201730.jpg
IMG_20171202_201654.jpg
 
Killer6 said:
It is time consuming to do a nice job---con.
It does retard how quickly carbon will build up in there, but it will build up eventually anyhow, smooth in form comparatively tho'---pro that diminishes with time.
Heat rejection is improved, but the amount is debatable & the effect degrades with the inevitable progression of the above---pro that diminishes with time.
The next time You've got 'er torn down, they'll clean up a lot easier---pro
You won't be removing more than 1-2cc's at most just doing that unless You start relieving the chambers on purpose, and there's really none on a smallblock to do,
so I wouldn't anticipate a problem with the squeeze. I have seen BB 906's (more than a couple) that have the chambers that represent cyl's 3&6 cast ~.025" shallow
compared to the rest,..that is an issue, and I've corrected them.
Click to expand...

Yeah but a quick suck of SeaFoam through a vacuum hose will clean any carbon right on up.
 
If you are CCing the chambers it may take a loooong time without any grinding.

They main reason to polish them if I understand correctly is to remove high pionts that could become essentially glow plugs and cause pre-ignition. As well as deterring carbon build up.
 
You can see some pretty nice gains with a rough texture similar to golf ball dimples in the porting job... lots of discussions about this on many sites.
 
Krooser said:
You can see some pretty nice gains with a rough texture similar to golf ball dimples in the porting job... lots of discussions about this on many sites.
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Intake ports only,?
 
toolmanmike said:
Intake ports only,?
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Intake, bowls and chambers. Done with a slightly bent carbide burr with a few teeth broken off to help the texture... golf ball dimples work, too.

Not worth for a street driver but sure works good on race motors.
 
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