Blowby, undersized Piston Rings, and 1/2 second

jimmyray said
Interesting. I was "sure" that I put them in according to the directions supplied with the rings, but then...

I plan on pulling the motor in a couple of weeks, and going through it. I recently had Bobby at BJR go through the heads, and have eliminated them as a root cause. I am thus left with these possibilities:

1. Uneven surface of the block deck causing blowby past the head gaskets - Bobby and I did notice there was carbon black between cylinders 4&6 and 3&7, as well as in other places, on the block side of the gasket.

2. Piston slap, out of round cylinders, excessive gap between the cylinders cuasing slight rocking of the piston or poor ring sealing

3. Ring issues - installed or gapped incorrectly, the undersize issue, or perhaps they were collapsed at start up due to a lean condition or running hot.

As you all note, the only way to know for sure is to pull it and disassemble it. However, I am going to try a leakdown test first. Incidentally, I have issues with leaking out of the dipstick at higher RPM from the beginning, it's worse now, though, since I have been inching the shift point up from 5500 towards 6500.

Hey 69Chgr, when you rebuilt, what changes did you make, and what was the result in 1/4 times?

Hey Jimmy,

I see the dot on the second ring, but I was referring to the top ring. I found the ring manufactures instructions to be a little vague on my set. I'd be more interested in seeing if the chamfer on the top ring is facing up(towards cylinder head) than I would the dots. I learned a hard lesson on mine. I only ran one time, and that was an 11.98 @ 113 before my motor puked so much oil out the front seal and valve covers at Ennis, Texas I had to stop. After fixing my rings, I had Ryan @ Shady Dell perform a Stage 2 port job, mill the heads, regrind the roller and match the intake. I don't know what it will run now as my new combo ate the A998! So I'd say a considerable much more, even still on pump gas. I could have sworn I've seen your car at the Texas Motorplex one year at the Mopar Nationals.