Cylinder wall stain marks

[wagoneer]

My B2B 230 engine seems to have been rebuilt prior to my acquisition but it's been sitting for a spell. I'm concerned about the stain marks on the cylinder walls, and worse worried it might be rust spots. Some are black and some have a little rusty look to them. How to treat them properly to get rid of them? I have wiped away some minor ones. I can see the proper hatching marks on the rest of the cylinders.

 

Help and advice please.

 

 

 

 

 

 

 

[soth122003]

The walls don't look that bad from the pics. Is the cylinder running at a lower compression? 

Short of pull the pistons and re-honing the walls, I would use a green scrub pad soaked in oil and lightly scrub the affected area. Put the head back on and run it. The piston ring will remove the stain after a while and Bob's you're uncle.

 

Joe Lee

Edited August 24 by soth122003

[wagoneer]

Would it be acceptable to re-hone the visible portions of the cylinder walls with the pistons in the car?

[Los_Control]

46 minutes ago, wagoneer said:

Would it be acceptable to re-hone the visible portions of the cylinder walls with the pistons in the car?

Depends on who's world you live in.

 

In my world I have a engine like that .... I used a 3" wire cup wheel in my electric grinder ..... the bores were 3.25 so it was not tight.

I very lightly touched the sides and they cleaned up perfecto!

 

I was just investigating to see what I had.

I then did disassemble the 1951 Ford Flathead V8 for a complete cleaning ..... I knew those cylinders were fine and before re-assembly would just re-hone them.

 

What you are suggesting will work fine for a old forgiving flathead motor ..... others will not agree.

 

[Sniper]

2 hours ago, Los_Control said:

What you are suggesting will work fine for a old forgiving flathead motor ..... others will not agree.

 

I've done that with a nylon abrasive wheel, finest grit I could find.  But it was on a 318, lol.

[soth122003]

That was going to be my first suggestion, but lots of people think you will get a lot of crud from the hone falling into the gap between the piston and the cylinder wall. This is true if you were trying to re hatch the walls. Looking at your pics and you say the hatching is still good, a quick hit with the hone won't hurt, depending on the hone. The hone that has the 3 bars fine. The hone that looks like a toilet brush with little balls on the ends, maybe not, as IMHO you will get a little more honing material to come off using that one.

 

Joe Lee

Edited August 24 by soth122003

[Los_Control]

10 minutes ago, Sniper said:

I've done that with a nylon abrasive wheel, finest grit I could find.  But it was on a 318, lol.

As a carpenter, a grinder with a  32 grit piece of sandpaper was one of my favorite tools.

 

When you create a curved maple rail for a custom home you do not need it .... the rail is sitting on the stair treads clamped down .... the next day when you raise it up in to position ...... then you start adding all the connections to the custom rails .... there are some cuts you can do with a saw .... most fitment is done by hand with a grinder and 32 grit paper ..... once you fit the pieces together then join them ...... now you can start using more conventional means to achieve a proper sanding finishing level.

 

For some of the finest carpentry I have ever done ..... A grinder with paper and a very light hand has created some great masterpieces.

I do not hesitate to use one ..... I caution others because it is such a powerful tool .... If I pushed too hard I could easily ruin $6K worth of materials.

 

Used properly and lightly .... it is your best friend.

 

A engine bore done very lightly will remove some minor stuff .... but not fix problems.

[Kilgore47]

I'll probably get a hard time for this.  But for an old engine it looks fine.  No matter how much you polish the stains the pitting will still be there.  In fact the more you polish it the larger the pits will get.   

12 hours ago, Los_Control said:

If I pushed too hard I could easily ruin $6K worth

Put it back together and drive it.   

[Dartgame]

Just an idea. Consider using some clay to lightly seal the pistons against the cylinder wall. I'd do this regardless of whether you hone, wire wheel, or sand. One at a time - move the piston 2/3 the way down, lightly oil wall near piston, seal it, and then sand, hone etc. Remove dirt etc as much as possible, then move piston down, and peel out clay, clean again, done.