Piston deposit removal

[flyman219]

I'm doing a valve job on my 2007 3.0 and I noticed a small deposit on the top of the #2 piston (Same cylinder that had 0 compression). I'm thinking it's a piece of the original spark plug that broke off sometime. I tried to pick it off with a putty knife but it's on pretty secure. I was wondering if I should just grab a dremel tool and sand it off as much as I can without scarring the piston. Or should I just leave it? I'm thinking it might create a hot spot and start some pre ignition or detonation problems.
Here is a picture of the booger on the piston top.

Thanks,
Mike

 

[DeepBlue2010]

It sure needs to be grinded down. You are spot on on your worries of hot spots. It would be a little tricky to do with piston inside the bore but it can be done

 

[NHGuy]

If the motor is out do it upside down. If not grind it while holding a vacuum cleaner to it.

 

[flyman219]

Thanks for the input,

Motor is still in the boat so I'll need to have the shop vac pulling as I'm sanding or grinding. I plan to mask off the entire top of the block when I do this with just the booger exposed to reduce the chance of sending grit where I don't want it.

Mike

 

[DeepBlue2010]

fill the grove between the piston and the bore with a molding clay or silicon as an insurance. You don't want the fine sanding particles to get in between.

 

[flyman219]

Thanks DeepBlue, I'll see what I can do to control the particles at the cylinder wall gap too.

Mike

 

[Bondo]

I'll see what I can do to control the particles at the cylinder wall gap too.

Ayuh,.... Grease,..... Coat/ pack the area yer protectin' with Grease,....

It catches everything, 'n washes out/ off nicely with most any solvent yer cleanin' with,...

 

[fishrdan]

Is the edge of your piston chunked up? Looks like it from the pic.

I've cleaned up carbon like that with paint stripper or oven cleaner, don't spray it on, put some into a small container and brush it on, use a rag/paper towels to clean it off and then a damp rag to clean off the chemical residue.

Ayuh,.... Grease,..... Coat/ pack the area yer protectin' with Grease,....

That's a good idear' Wished I would have thought of it, but then again, I'm not the Grease Ninja