Technical quick chevy ring gap question please

engine is 40 over, with some wear - 4.040 plus wear

does this ring gap 'look like' stock 4.000 rings

 

looks like to much gap. You might be right

 

Wouldn't a .040 increase in diameter equal about 1/8" increase in circumference, or about how much too large that looks? Meaning yes...

 

something about a couple of pies and a pirate......
anyways, bought a motor in bits - a heavy smoker -60 a day by the look of the spark plugs and valves
ALL of the pots were bad
the question then is, do I simply buy 4.040 rings - knowing I have some wear, or do I get file to fit slightly oversize and file them

stock is 12.56
40 over is 12.69
.13 of an inch in the metric as I don't have a clue what .13 of an inch looks like is
3.3mm

so yes, that would suck oil up like a sponge I suppose

 

do it right and punch it out to .060 over with new pistons and rings

 

.004 per inch of bore. If it is a used bore check it top to bottom also!

 

you can buy pistons for SBC in any size,so you can bore it a couple .001.They have been doing that on sprint cars for years,the block last a long time.

 

Used to be .004 per inch of bore was the rule of thumb

 

I had a .060 over 350 that had some wear and I needed a motor for my dirt track the next week.
Couldn't find a block so I bought some .060 over file to fit rings and put it together. It was supposed to be for a few races until I could find another block. Well we started winning races and that worn out block won 23 out of 26 races and gave us the points championship that season.
It eventually got an .080 over bore. Sonic check one before you try that. It was a 4 bolt one ton truck block.

 

It might not be the case here, but hyperutectic pistons require a bit more end gap. It's been a few years, but I believe Keith Black hyperutectic pistons had a spec. of about .007"/inch of bore, at least on the top ring. I had a customer who years ago about ruined a circle track engine with hyperutectic pistons in a few practice laps because he threw it together paying no attention to ring end gap.

But, that said, the gap seems excessive as pictured in the original post. I agree with ROADSTER1927's suggestion. Push the ring to various positions up and down the cylinder and square it to the bore with an upside-down piston and check the gap.

Lynn

 

I had a dummy tool I made up that located the ring 1" down into the bore. Sort of a sweet spot an old timer showed me. The tool was made out of a couple pieces of phenolic plastic sheet. It would place the ring square in the bore.