V12 Engine Problems

[Bored&Stroked]

Originally Posted by Ken/Alabama

Got 300 plus miles on the V12 in my Zephyr. Runs good and has good power. Stock engine bored .060. Changed the oil ,had 30 Weight in it during break in. Put 10-40 in it . Took it on a 500 mile round trip with no issues. On the return trip I noticed I begin to smell something like blow by coming from the engine. When I got home I raised the hood and revved the engine. Getting lots of blow by from the oil filler and smoke from the tail pipe. It's like the rings unseated, I've rebuilt many flathead V8s and a few V12s but never seen anything like this.

The fact that it wasn't there before - and now it is, makes me think that something has failed. Potentially a broken ring would be my guess.

I would do a compression check first -- if that doesn't show anything obvious, then I would proceed to a leakdown test.

D