Technical cylinder cross hatch

I came into a sbc recently with 4k on the clock that had been rebuilt and had machine work done by a reliable source. This came to me in a trade and was up and running with no issues.

I'm taking out the dish pistons and going with flat tops. The existing pistons have the moly top ring and I will put a new set of moly rings on the flat top pistons also.

New pistons and rings in 8 very nice clean cylinders that of course show the cross hatch quite clearly as you would expect. This was bored (+.030) and honed with a plate on it.

Question is how far off base am I to think that I can replace the existing pistons and rings without even having to use a glaze breaker? Seems like I've either heard or read that.

The holes certainly don't need a ridge reamer by any stretch and as far as a glaze breaker goes would we be thinking ball type or stone.

 

Should hone it. I wouldn't want to tear it apart again because I didn't take the time.

 

I agree and I would check the piston wall clearance before I decided what to use for a hone, if it is right now with the new pistons I would use a bottle brush and if it was tight I would use stones.

 

Agree, I'd run a "flex" hone thru it to give the rings something to seat to.
http://www.brushresearch.com/brushes.php?c1=2
Get a fairly fine version, 320 or 400.
I recently did the same thing on a "quick" rebuild.

Mike

 

I'm with ****** on this. If you could look at the cylinder walls under a microscope, you would see that the material was tiny peaks and valleys with the tops of the peaks knocked off. If it was honed correctly, which it sounds like it was, there would be no metal folded over. The bottle brush would just clean out debris from the valleys. If you would get aggressive with a hone you might do more harm than good.

 

Don't take short cuts.

 

if you're using moly rings, I'd probably leave it alone. Modern engine machining is a bit different than when most of us learned decades ago....turns out, a smooth finish is just fine with modern rings.

 

Hastings want you to "bottle brush " it , there grit of choice is 240..
dave

 

Modern performance "Moly" rings take a slick surface. In my work, I use a CK-10 or a CV 616 Sunnen hone. Final p*** with a torque plate, is with a very fine stone. Then a "cork" or "plateau" stone that knocks the points off the cast iron grain. Makes the cylinder finish darker in color and like a mirror finish. Very little, if any cross hatch is visible.

My drag race customers replace only the top ring on scheduled refresh, during the season. .No hone or glaze break. Some say they get a better seal on re-ring with the type of ring they use. Feels strange to turn over a fresh short block that has no ring drag!! Like no pistons in the thing.

As you don't know how this engine was honed. I would use a brush hone, just a couple of strokes per cylinder..

 

Molly rings like relatively smooth bores. The old cast iron or chrome rings needed to "seat", but modern rings are ready to go and factory bores are much smoother than old school engines.

Leave it alone.

 

If it were mine I'd run a bottle brush through it and then use bunches of paper towels and lacquer thinner to clean the walls. Don't stop until there is no black (racist *******) anywhere on the paper towels.