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-   -   Repair combustion chamber and piston top (https://www.racingjunk.com/forums/showthread.php?t=30713)

robinh 07-19-2011 09:25 AM

Repair combustion chamber and piston top
 
I had a foreign object (carb vent tube) fall into the engine and enter two cylinders. The damage is confined to dings on the top of the piston (forged) and head combustion chamber (aluminum). My question is can the dings be ground and polished down? If so, what would be the recommended procedure and tools? Thank you.

TheYellaBrick 07-19-2011 09:40 AM

Street - race - high compression ?
Depending on exactly how much any grinding/polishing it will be removing materiel. The end result is change of cylinder volume/compression ratio.
Got Pics ?

robinh 07-19-2011 01:47 PM

it's a race motor with 13 to 1 compression.

here's some pics:

[img]http://img577.imageshack.us/img577/3...mg1190u.th.jpg[/img]

[/img]http://img197.imageshack.us/img197/9...mg1194p.th.jpg[img]

[/img]http://img5.imageshack.us/img5/1507/cimg1193q.th.jpg[img]

[/img]http://img812.imageshack.us/img812/9...mg1192w.th.jpg[img][/img]

I realize I'd be changing the compression ratio. Just want to smooth things out to avoid detonation.

wazup 07-19-2011 04:52 PM

Get a port and polish kit and it will clean up fine with that. I would pull the pistons on those cylinders and check the ring lands and make sure the rings move free and check the valves to make sure they did not get bent.

Good luck i hope it turns out well for you.

Robert Fla.

TheYellaBrick 07-19-2011 07:33 PM


IMHO; I'd replace the affected pistons, smooth out the heads, CC the affected/smoothed chambers, and match the rest of the good chambers on both heads. CR will be a tad less but all the cylinders will be the same.

------------

zipper06 07-19-2011 07:34 PM


Originally Posted by wazup
Get a port and polish kit and it will clean up fine with that. I would pull the pistons on those cylinders and check the ring lands and make sure the rings move free and check the valves to make sure they did not get bent.

Good luck i hope it turns out well for you.

Robert Fla.

Spot On.

JMO

Zip.

TS1955 07-20-2011 09:07 AM

I agree with DD. Replace the pistons on the two cylinders. Repair the chambers. The pistons could have small fractures and come apart. JMO

TS1955

robinh 07-21-2011 08:41 AM

I think replacing the pistons and repairing the heads is what I'll do. Thanks for the advice.

itsabird 07-21-2011 10:05 AM

Good advice, i have seen a lot worse, maybe a light reserface pass on the heads.


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