I recently changed the cam on my 79. It came to me with a bad cam and this is the first thing I "fixed". The cam is an xe268 from comp cams, I pre-oiled the engine before dropping the dist in, added cam break-in fluid etc.
She fired up right away and ran for 25 min at around 2000rpm. Everything seemed good. Time being short as a father of two small boys, I have only started the car a couple of times since and run it for a half hour or so to keep it fresh. There are a couple of leaks around the exhaust manifolds & small drippage from the breather on the valve cover. Nothing too exciting just had'nt got around to fixing them. I changed the wires over to msd 8.5 mm at this point as the stock wires were pretty beat up.
Anyway, to get to the point. Today I started her up with the intent of setting the advance and taking her for a ride around the block. BIG TIME SMOKE. Oil is dripping from the left manifold nr. the the heat riser and also at the inlet to the catalytic converter to the ground. Needless to say there is a lot of smoke out the back. I am totally confused as to what could "let go" or work loose to produce this much smoke. The engine sounds unchanged to my eneducated ear. During the cam change out I left the heads in-place and did not mess with them. When I got the car the cam was ground round at 2 & 4 but did not smoke like this. How would I troubleshoot the source of this? Cylinder head or bottom end? Ineed help from someone a lot more experienced than me. Thanks for reading! I need a beer!
Cheers

 

Pull the valve coversand see if the oil is draining down and the passages aren't pluged. I had a freind whos son had put some rags in the holes to keep dirt out while they were working on his and fogot to remove one and he had the same thing happen. If thats not it then put the intake off and reset it. I have seen some where the gaskets moved during the install and let oil free flow into the cylinders.
Good luck

 

Valve guide seals?

 

Thanks for the suggestions. I will check them once everything cools down. If it was a plugged oil galley or moved intake gasket why would it show up now & not at start-up?
Could upgrading the ignition wires be involved with this? I was heading down the road of a burnt valve...
Keep the input coming, all help appreciated.
Abdy

 

Poor intake gasket sealing. Oil is being drawn into the cyls. Gotta redo the intake gaskets bro. If using an aluminum intake you'll need MrGasket or equiv. paper type gaskets or proseal from FelPro. Use hi-temp silicone on head side of gasket and the 4 corners of the head to block area. Only silicone on fwd and aft portions of block (no rubber seals). Also silicone the first 3-4 threads on your intake bolts prior to install. Torque in 3 steps to get to max and retorque at max at least twice in the first hour. Wait 24 hours (to set silicone) prior to firing the engine. That should do it.

 

Thanks for the help guys. Hopefully it is just poor intake gasket sealing. I am confused as to why it would only manifest itself on the third start-up though.

 

I put hy-tack gaket sealer on the side that goes to the heads. Then I place the intake on and snug it in place. Let it set for a couple of hours to setup, then remove the intake and check the position of the gasket. Then if everything is good I reset the intake and follow the three step method to torque it down. The I retorque it after I run it up to normal operating temp. It usually takes 2-3 times before it seats in. It may have taken a couple of runs before the gaskets lost there ability to hold if they were on the edge of not sealing.

 

I see you used the break in lube. This is good. :yesnod:

I do NOT see where it says you changed your oil after the break in time. The break in lube is a moly based lubricant and can/will clog your oil filter which will cause the by-pass to kick in. ( same as NO FILTER ) :eek:

I agree with the others above, it does sound like the intake gaskets moved.

:seeya Jeff

 

There are several different sizes of intake gaskets for small block Chevy's. I would probably remove the intake and make sure that the gaskets match the ports on the intake and also match the ports on the heads. This is especially true, if you are using an intake that is not the original. And as mentioned earlier, throw away the two rubber end gaskets, and use silicone.

Trust me, I've been building these for 40 years.

Good Luck

 

:iagree: with Phil

 

I have to agree with the valve guide seals.

BTW, you can have the beer below. :D (just click it) :thumbs: