Ok, I'm getting a little blow-by in my brand new built 383 from coast high performance at coasthigh.com. I asked them about this, and this is what they told me:

Most likely what has happened is you have not sufficiently relieved the
pressure in the oil pan. This will result in pushing oil around
everything. As well as creating blow by. Remotely, if you used regular
oil instead of non detergent you washed all the moly off the rings and
they didn't seat correctly.

I personally have never heard of this, not to say it isn't right, but can someone give me some insight to this? Thanks.

Josh

 

Blowby gasses are what leaks past the compression rings. Poor ventilation can cause oil leaks but not blowby as that's the cause, not the effect.

Non detergent oil helps in breakin as it allows a bit more friction to help the rings to seat. GM doesn't use it, Ford doesn't use it. Some cam manufactuers recommend it during flat tappet breakin. Non-detergent oil is usually the cheapest oil at the parts store in their own branded bottle. Its not very high distribution.

Moly doesn't "wash off" the rings. Its a filling sprayed into a grove of the compression ring that reduces wear. When you tear into the engine after several tens of thousands of miles the moly will still be there.

Modern moly rings will seat just about as soon as you load the new engine for the first time provided the hone isn't out of wack. All bets are off if you didn't dilligently scrub down the cylinders until clean before assembling the short block.

You should also describe what "a little blow by" is. If you're seeing smoke or vapors without any pressure behind it on a brand new engine that it may well be fine. Blowby will cause oil to push out of the breathers and make a mess on the valve covers or where ever you're venting from.

If you haven't gone out and stood on the engine yet, shame on you. Go out and get on it a bit. Not super high rpm, but lean on it some.

 

As far as oil goes, I'm using royal purple, so that wouldn't be it. The block was already assembled and balanced at coast high, so if there was a problem with it, it should be on them?

I WAS using the pcv system AND had a breather on the valve cover. I did play with the car a little bit, and my dipstick popped out and vapors were coming through the breather. I since then took off the breather and hooked up the pcv sytem better, but I haven't had a chance to drive it because I'm waiting on a part to come in. As soon as that's in, I'll drive it again and see if that helps.

So, basically, the people at coast high have excessive blow by because they blowing me a bit of smoke up my ***? Or would that be me having blow by because of the smoke that's filling my ***?