Plain cast rings bad?

Nice, thanks.

Plain cast rings are fine for most passenger car applications that don't see high temperature, RPM, or dirt conditions for excessive periods of time. I tend to consider trucks, tow vehicles, or anything that sees a lot of off road duty a step above this. This usually dictates moly coated rings. Moly is nice because it retains oil in its porous surfaces. This will reduce wear and scuffing in the right application. Chrome is for severe dust and dirt conditions, and isn't really recommended for normal car/truck use anymore. Moly is more than likely the best choice for a typical off road vehicle, including yours. The rings are still cast or ductile iron, but they have the moly coating on them. Top of the line moly rings will be plasma coated, but these are quite a bit more expensive.

Remember that whatever rings you decide to use, you need to do this before you have the block bored and honed. This is because each one of these ring types needs a different hone finish in order for the rings to seat properly. If the bores are honed properly, the moly ring will seal the fastest of the three, and chrome will take the longest.

One other thing to watch for is oil ring tension. You want to make sure you get standard tension oil rings. Racers use low tension oil rings in order to reduce friction, but these do not last nearly as long, and will exhibit more blowby under daily driving conditions.

If you want to get real fancy (be prepared to pay for them), you can go with the gapless second rings that Total Seal and Childs & Albert make. These rings eliminate the ring end gap on the second compression ring to reduce blowby. They are good for a few horses, but like I said, they are pricey. The biggest advantage to them is that as the bores wear the ring end gaps get larger which increases blowby. the gapless rings will remain gapless even as the engine wears.

Chris

Now this caught my attention. Coud you describe how these 'gapless' rings work? I can only imagine a tapered overlap instead of a flush end where you would normally have a gap. Other than that, looks like getting one on would be problematic, to say the least.

There are two different designs. One uses 2 rings in the groove (Total Seal), and the other uses a stepped end on the ring. The Total seal uses compression pressure to help seal the ring as well. I've used both and they both work good. Total Seal has a street type ring that works great for anything but all out racing. The racing version has a low tension oil ring and a different type of coating on the compression rings.

Total Seal:

Childs & Albert: Here's a good article on ring technology: This is based on the C&A rings. Chris