I have about 300 miles on my 383. Relavent specs as follows:

TRW forged flat tops, PN L2256, 0.004 bore clearance
Speed Pro ductile file fit rings, 0.018" top gap, 0.012" 2nd ring gap
Bored and honed with torque plate
195 AFR's
9.8:1 SCR; 7.8:1 DCR

I pulled the plugs for an inspection (call me paranoid) #1-6 and #8 were textbook normal. #7 was wet with oil and the porcelain coffee colored.

I ran a compression check on #1 and #7, cold engine, throttle plates closed. #1 had 170 psi; #7 had 175 psi.

I also pulled the valve cover and verified that the valve stem seals are indeed installed on this cylinder.

Any idea where the oil is coming from?

Oh yeah, #7 has a sleeve, but I am absolutely certain it was installed properly.

Look forward to your ideas.

I`d have a look at the intake gaskets.

Jim

I had the speed pro plasma moly rings installed in my freshly bored 396/now 402 with speed pro forged slugs which was using a fair amount of oil until i got 800-1k miles on the motor which was scary.

My machinest said these type rings are made of a very hard material that is more resistant to detonation which also makes them take longer/more miles than std rings to seat.

This worried me to see my car using oil up until
approx 1k miles because any motors i rebuilt in the past didnt smoke even when they were just a re-ring on old worn cylenders with just a glaze breaker.

So don't panick yet,some of my plugs looked dry and some had some evidence of oil before all the rings seated because some cylenders/rings just took longer to seat than others did.

If you check out your intake and it's not leaking i would wait until you get approx 1k miles on the mil to give those hard rings time to seat.

If it's still using a lot of oil after 1k miles i would then replace the intake gaskets and have the intake magnefluxed at the same time for cracks while your at it.

If your intake is good and your mill still uses oil after the new gaskets i would maybe look into the possibility your carb was too rich on startup thus causing a fuel wash problem in the cylenders
preventing the rings from seating properly.

If your running a perf cam with a fair amount of duration be sure you have enough intial advance dialed in (approx16-18 deg btdc) to ensure it's not causing low intake vacuum at idle due to overly retarded timing . Retartded timing can cause lower idle vacuum making the power valve in the carb to open too early resulting in a rich mixture causing in fuel wash that stops the rings from seating properly.


Also,after you check the timing you still need to check your idle vacuum to ensure youv'e got the correct power valve installed in the carb so it is not open at idle or low/part throttle settings resulting in a rich mixture. If thats what is happening to you right now it could be part of your oil burning problem due to fuel wash on startup impeading your ring seating so check it out.

Is it possible the sleve in #7 was not honed or not honed properly and the rings are not seating?

Also,is your pcv valve/system possibly sucking up any oil into the intake?

Let us know how you make out.

Scott

Thanks for the input.

I'm currently running a 1850 Holley with 66 primary jetting. It is not too rich. Initial startup went flawlessly. Started on the first crank and headers didn't even glow during cam breakin.

The cam is a mild hydraulic. Pulls 15" vacuum out of gear and 12" in gear @ about 600-650 rpm. I'm running 22° timing at idle with the vacuum advance connected and 36° total, not including the vacuum advance.

I've already had the intake off to check the gaskets. The block was decked true, and the imprint on the gasket was all around. Plus, if the intake were leaking, I'd think it would show up on the entire left bank.

I have baffles in the valve comvers. These same covers were used on the previous 327 and did not suck oil through the PVC system.

I think all the rings except for #7 have seated with no problems. This thing pulls 21° vacuum on the highway at 3,000 rpm and the plugs look perfect.

One symptom I forgot to mention is that under WOT, crankcase pressure pops the dipstick. The more I think about it, chances are I broke a ring or installed the second compression ring upside down during assembly. I don't see how it could have happened because I was extremely careful, but S*it happens.

Again, thanks for input. It keeps me thinking.