burgessdg

Putting together a 383 chevy motor. I have always struggled with this subject. I have a couple of diagrams. All of them show basically the same pattern and it appears that they are telling you to put the 1st compression ring perpendicular to the wrist pin and second compression 180 degrees from that and then the oil rings and separator in another pattern.

My conundrum is that the one diagram does not say to rotate the pattern from bank to bank. It references the front of the engine and left and right side. My interpretation of the diagram is that I would set the pattern in the same orientation looking at the top of the engine. So, I would have 1st compression on the thrust side of the piston on the passenger side of the motor, and the 1st compression on the non-thrust side of the piston on the driver side. This has never made sense to me and I believe I have always modified it to put 1st compression gap on the non-thrust side on both banks and just follow the pattern from there.

Any definitive knowledge out there? I have searched the internet for 2 days, including several piston and ring manufacturer sites with no good info and no definitive answers.

Thanks in advance,
Dan

mr.beachcomber

Interesting question. I've always installed the rings as recommended by ring/piston/engine manufacturers. I couldn't find anything definitive in reference material nor the Internet either. The two things that are most important in ring installation (after having the correct cylinder surface for break-in) I've found are (1) getting the ring gaps correct (wide enough) for the intended engine usage, and (2) orienting the ring gaps so that there is no direct path past the rings for either oil or combustion gases.

That being said, your proposal to switch ring gap orientation patterns such that actual gaps are not on the thrust side of the cylinder may have merit. I'll try it my next build.

If you do find a definitive answer anywhere, please post it to this thread! Thanks!

burgessdg

[QUOTE=mr.beachcomber

If you do find a definitive answer anywhere, please post it to this thread! Thanks! [/QUOTE]

I also posted this question an another forum. Still nothing definitive (well almost nothing). Mostly the opinion is the rings move in the bore and on the piston when running, so why care...

I did get a link to hastings rings document. I really just pulled 2 things out of that. 1 - hastings says put ring gaps 180 from each other. 2 - If your hone job is not cross-hatched and slanted in one direction only, it will cause excessive ring rotation.

I am just gonna draw something up for my reference so I'm not asking this question again. I do know one thing that is not often addressed is that if there are any scallops in the cylinder bores (like a big block) you need to keep the gaps out of those scallops so as not to break a ring when putting piston in the bore.

But if I do get something definitive, I will share.

Dan

Apocolipse

Rings rotate around anyways, you do the initial so they have a better chance of not lining up when they spin at the same time.

C409

..... The rings are always "clocked" to the front of the engine because the right side of each cylinder is the load side . Right side as looking towards the front of the engine . The crank rotates to the left (from the drivers seat) putting the connecting rods at an angle to the piston that puts more pressure to the right sides of the cylinder walls on the power stroke . The clocking is intended to keep the ring gaps out of harms way in terms of wear , tear , and load .............

RobnLisa

As Apocolipse said, rings rotate. The most important thing is gap. Gap the rings and just be sure they are not lined up when you install the pistons.