I've got a 383 stroker that I built in my '78. I've had it in for over a year now and it runs very well. The problem is, that I've had a small oil leak and after spending a couple of hours locating it, i have discovered that it is coming out at the left (passenger) side rear head where the head meets the block. I have checked to see if it originated at the distributor or the valve cover. Aftere checking, I am sure it is coming out of the rear corner of the head. The engine runs very well and the oil is not contaminated with coolant or water. Has any body experienced this problem before. Also, any ideas on fixing the leak. (it leaks about a quart every 200 miles) Thanks in advance for your suggestions.

Steve

 

My best guess is the oil is from the rear corner of the valve cover, but two quarts every 200 miles is excessive!!! Is there a puddle under the car when you park it? Are you sure its not burning oil? A quick look at the plugs would tell whats goiing on. I am fighting an oil leak too on my new 383..looks lik my rear cam plug is seeping....best of luck

 

MBEEMAN350, thanks for your reply. I'm wrong about the comsumption rate of oil leak.. It's actually about one-half quart every 200 miles. I'm sure its not burning oil because the plugs are clean. I am sure the leak is at the rear left head. I'll probably start by putting a new head gasket on and see if it helps. Thanks again.

 

My 350 does the same thing. The car has "smoked" whenever it's driven above 55 mph - and I mean visible blue or white (hard to tell sometimes) smoke in the car. I've fixed leaking intake gaskets, radiator leak, brake lines, fuel line, valve cover gaskets, oil pan gasket, distributor gasket, thermostat housing gasket, lower rad hose, heater hose, and installed a bolt in the fuel pump pushrod hole on the front of the motor. Just took the car out today thinking the bolt I put in the front of the block had fixed my last leak. Got the car up to 55 mph and - smoke coming from the passenger side vent! Good thing there aren't any cliffs around here to drive off!
Anyway, cleaned the passenger side of the block, starter, and headers again and proceeded to rev the engine a few times to find the leak. It only leaks if I rev it up. Saw some blue smoke from the rear passenger side and noticed some fresh motor oil dripping on top of the solenoid. It doesn't seem to be coming from the valve cover and the bottom head bolt under the No 6 plug seems to be fairly "wet" with oil. Could enough oil permeate through those headbolt threads to leak that much? I don't remember if I used any sealant on those suckers when I swapped heads. Maybe the head gasket is bad? Also noticed my rear header bolt is missing! Maybe that rear bolt goes into the crankcase and oil is running out the open hole onto the head?
Sorry for the long post, just thinking out loud, as we seem to be in the same, leaky, boat!

 

Your leak is either from the intake end seal or the v/c's. There's no high pressure oil port or oil returns in the head gaskets on sb chevys. Could be from the oil pressure sender also, either from the body or NPT threads.

Couple of tricks we use are oil dye in the oil and/or RTV dam across the head and block edge. This way anything leaking down the joint with be deverted away making it easier to pinpoint.

Can get cheap oil dye kits at the partstores now that come with the dye and a cheap UV flashlight and glasses. Just clean the area with degreaser, add the dye and drive as normal. Later pull it in the garage, kill the lights and you'll see the leak. Warning - you may find more leaks than you originally thought you had.

Additional info:
Make sure you have the pcv and a vent in your crankcase ventalation system. A change to new v/c's with failure to use both holes (1 each) can cause crankcase pressures that will build up and blow out gaskets. Such as intake end seals, v/c, and others.

 

Or should I say, found my last oil leak? Anyway, I just replaced my dipstick with a new Lokar unit. The old stick was missing the mounting tab and had two 1/8" holes where the tab was probably spot welded. The stick did not fit very well at all, either. I easily pulled it out of the block. The Lokar didn't really fit very snug either, but it does utilize a rubber O-ring at the sealing surface to the block.
Just took the car out on the highway and NO MORE BLUE SMOKE! HA! It has only taken me 4+ years to chase this gremlin down, as I don't really drive the car much.
Now that there isn't a bunch of oil leaking from the side of the block I can see all my tranny leaks! Next project - 700R4.

 

ECPirate take a look at this pic

Right there at the rear of the head mating surface(left head) you can see a oil plug.It's towards the top almost at the intake manifold parting line. Make sure thats not where your leak in coming from.
Yes you must remove the head to access that plug.
Thanks to whoever I stole the picture from(sorry I didnt write down the name)

 

Had the same problem with my 383, a check with the dye kit previously mentioned comfirmed it was the oil plug. Had to pull the head again, but I got the leak fixed