Hot Rods Oil on plugs

I have a new rebuilt 396 BBC with 8-71 Littlefield driven at about 10 over because I'm at 4700 ft. elevation, about 20 miles on this motor and have oil on the plug threads and electrode. I have breather on both valve covers, is it the wrong type of rings or does it need more ventilation, any thoughts, thanks, Alcoholnova

 

It's pretty hard for us to tell....we don't know anything about the rebuild, or what type of breathers you have, etc. It's been my experience that plug threads on BBCs collect oil, after a while. But the electrodes should be dry.

If you tell us a lot more about the engine, we might be able to start trying to figure it out. I've always done a mostly stock rebuild on my blown big blocks, nothing fancy, and they work pretty well.

How much boost is it making? That's a lot of blower for a little 396.

 

Details man...we need details...! None of us have "crystal balls" to view into !

Low tension rings ?
The rings broken in yet ?
The correct cylinder hone for the given ring ?
Did you use valve guide seals on all valves or just intake ?
Proper valve guide clearance ?
Intake manifold leaking ?
Blower leaking oil ?

There's a coupla things for you to check into...

Mike

 

20 miles doesn't sound like mucn break-in time, does it?

 

I’d be inclined to put some more miles on it to be sure the rings were bedded, if things were done correctly. Re- torque the top end bolts and give it some more miles, your at elevation, run it up and down some good grades

 

Thank you, this motor is a 1966 396 .030 over with forged pistons with a small dome in 119 cc sq. port heads, I've used Hell Fire rings in the past I used Total Seal this time, stock oil pump, one cylinder is putting a bit of oil out the end the zoomie. the breathers are basic stock type which may more restrictive than I thought,,,,

 

Thank you that is good advice, I'll let you know

 

Yes that is true I'll give it some more miles, thanks