I finished building my 355 last month. Long story short it is still burning oil. Not as much as it used to but it still is. It used to burn about 1 quart every hundred miles. Now it is down to one quart every 300-400 miles. I have about 1200 miles on it's clock right now. It is a roller camed block with roller rockers, double roller chain, and I have heard the it takes longer for roller camed blocks to break in.

My plugs are not fouling with oil and the oil looked good when I changed it the first time. No antifreeze or anything. When I rebuilt other engines they burned much less oil, but they had much more friction loving parts. The pistons seemed to go in really tight. I used moly rings if that would matter for break in. I have not done a compression check yet. But just how much oil is a normal roller block going to use and how long?

 

Were the cylinders honed for Moly rings? Makes a difference on how/when they'll seat.

Since oil consumption is less as miles go on, something must be seating, but I'd still be concerned about a quart every 100 miles and even every 300 miles. Are you driving it hard?

 

most rings seat fairly fast anymore. i'd run compression and leak it and if all looks good there i'd look at the intake gasket or maybe just replace it.

 

I am not sure if they were honed for moly rings. I have the hypreutectic pistons with the heat/thermal coating and I know I said to have them honed for it.

Intake gasket sounds familiar. I have the HSR and have heard some bad stuff about a HSR and intake gasket with oil leaking past it. My current CR gauge will not fit in all of my plugs and I will have to buy a new one first.