Excessive Blow-by on Fresh Engine

[G72Zed]

I had what I thought was blowby. Turned out the carb was sucking oil through the hose that ran into the breather of the valve cover.

Discuss with your builder, he may in fact have further details and information on a updated or "restricted" PCV setup for those style of rings he swears by. Again, assuming it's a Gapless Top ring pak.

The engine builder is probably right. Is that 600 easy cruising miles? It is barely broken in. It's time to hammer on it a little and do some deceleration runs to seat those rings.

And hence the reasoning for my questions on some details, it may in fact be difficult to "seat" the rings now, pending on how it was broken-in in the first place, high decel runs may add to the "blowby" issues.

 

[G72Zed]

Torque plate honed?

I had asked this question, I assume it would be, not much sense skipping this very important step, and in light of using premium higher cost rings on a used bore without the proper prep is asking for trouble. Just my direct experience.

 

[CNC BLOCKS]

I don't care what rings you have if the block was not plate using the correct gaskets and hardware used in the end build, Using a good hone is a big plus and knowing what your doing. Those rings will not seal. I build a lot of circle track engines and have seen guys that have block machined and not plate honed and after 2 years of racing fail a leak down test which indicates the ring did not seal. To the OP do a leak down teat # TDC and 40 degrees after or before TDC. see what happens
Here is a link to look over
https://www.chevelles.com/forums/148-2005/93364-values-torque-plate-honing.html
How can rings seal with cylinders that are not round.

 

[CNC BLOCKS]

This is a factory 454 block .030 that was machined by another shop. I have seen work from this shop many times and their work has always been spot on. This is a marine build went to plate hone the block and measured the cylinders they were .0035 distorted. I can not stress enough that on factory blocks plating honing is a must to achieve good ring seal. People say the rings will break in LOL I have seen circle track engines with rags around the breathers for 2 or 3 years leak them down up to 35% leak down. I have always said its best to do a leak down 40 to 50 degrees BTDC or after TDC. Here is an article I did on plate honing years ago
https://www.chevelles.com/forums/14...KYUVefvkKTDtrASQlbQL35qmRHjh16NrlhkkkWTSDDaDo