Head Deck Scratch

[SchmidtMotorWorks]

Thanks for the idea but I'm not sure I follow this one... In order to move the material, won't the punch actually make other indentations in the surface? I guess I'm just not sure where the "filler" material will come from without further damage.

When you punch a dent into a piece of metal, an equal volume of metal will be raised around it.
If you do it carefully, you can drive a wave of metal toward the low spot.

Start by punching about 3/8" or more away from the spot you want to fill.
Aim the punch towards to spot that you want to fill by making it maybe 20 degrees from perpendicular to the deck.

After the first punch make one to the left and one to the right by about 1/8" to make a trough like you see between two waves.

Next punch the wall of the trough over to the gouge.

If you have something very flat, you can see how much it bulges.

Resist the temptation to file down the bulge to see if it will clean up.
Instead, beat down the bulge with something flat, then file it flat.

This is a common way to repair very large molds and dies weighing many tons (sometimes valued in the $millions) when they are in the press and cannot be welded.

[rfoll]

Using the smallest possible bore is a not widely-known speed secret. The reduced crevice volume has a disproportionate benefit, since the not usefully-burnable mixture is compressed into it by as much as 100X.

Bill, agree completely and I work to reduce crevice volume/increase squish/quench on the obsolete stuff as well. However, as is our wont, I'm taking this further OT; recently we were discussing piston top design and how now pistons have high ring groove placement to reduce the crevice volume you referenced.

Then, my machinist brought out a OEM 350" SBC piston from a time period where GM machined an approx 45-degree taper around the circumference, making for a huge crevice volume.
Earlier and later pistons were the traditional flat-top-with-valve-reliefs. What was GM thinking with that beveled edge, as that's been bad science forever?

I heard this was an emissions device to keep nasty things from growing in the crevice. I installed Vortec heads on an engine with these pistons, and at 8.6:1 CR, it pinged on regular gas. Quenchless design piston.

[Alkyfool]

That bevel design it the worst thing to have when a combustion chamber is detonating. The decreasing cross-section speeds( looking as 2 dimensional) up the flame or combustion pressure wave and puts it right on the top ring.