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FE Power Forums => FE Technical Forum => Topic started by: Boiler Ben on August 31, 2024, 08:04:03 AM

Title: cylinder pitting
Post by: Boiler Ben on August 31, 2024, 08:04:03 AM

I have 7 nice looking cylinder walls in my 390.  Number 8 has some pitting as you can see in this photo.  This is not an extreme build and won't be raced, just a fun driver.  Any concerns with this?  Anything special I should do?

Title: Re: cylinder pitting
Post by: blykins on August 31, 2024, 09:45:31 AM

Can you feel them?  A pit is different from a stain.

Title: Re: cylinder pitting
Post by: Boiler Ben on August 31, 2024, 12:42:39 PM

I can feel them, but only very slightly.

Title: Re: cylinder pitting
Post by: blykins on August 31, 2024, 02:34:11 PM

I don't like to see them but they don't seem to hurt anything.

Title: Re: cylinder pitting
Post by: oldiron.fe on August 31, 2024, 03:00:31 PM

                                                                                                                                                                                                                                                                                                             clean pit-nothing to loosen-low in bore better-ring width wider than pit better-best thin quality ductle sleeve for harder use-good luck--oldiron-john   

Title: Re: cylinder pitting
Post by: Barry_R on September 01, 2024, 06:41:44 AM

Quote from: blykins on August 31, 2024, 02:34:11 PM

I don't like to see them but they don't seem to hurt anything.

Kinda the same feelings - - as long as none of them are deep enough to bleed coolant.
Probably 95+% of them are OK to use in a street build.
Should have been pressure checked before assembly.
Even then, you won't really know until they are running under heat and pressure.

Title: Re: cylinder pitting
Post by: pbf777 on September 01, 2024, 07:27:53 PM

      Nope not ideal but, I would highly doubt that that sum of irregularities would create any noticeable problems, and amounts to a far lesser evil then boring to the next size up, or sleeving that cylinder would be.   ;)

      Scott.

Title: Re: cylinder pitting
Post by: Boiler Ben on September 02, 2024, 07:05:46 AM

Thank you guys.  I will go with it as is.

Title: Re: cylinder pitting
Post by: Falcon67 on September 03, 2024, 10:00:40 AM

This is one of the cylinders in my 351C post driveway hone job.  There's a couple with similar stuff.  The engine runs fine, no issues.  No blow by, oil clean, plugs look good. Typical dial is around 7.39 @ 92 MPH in the 1/8 at 3250 lbs race weight, air shifter set at 6200.  Cylinder fresh hone with lube and 320 grit hone, then ball hone with lube, new moly face rings.  It's a thin wall block, already .030 over, just going to run it until it falls apart.

(https://raceabilene.com/misc/351cNotes/2023/Cyl2.jpg)

Title: Re: cylinder pitting
Post by: Phil Brown on September 03, 2024, 10:25:29 AM

Think of them as mini oil reservior's for the piston skirt  ;D