I finished building my engine not too long ago it is a 383 carbed. I did not have it running very long because I heard the rockers were not adjusted correclty and so the story begins...
A few weeks ago when I went to readjust my rockers. I took off the valve cover and it looked as though the oil and coolant were mixed together. I asked alot of people and the final verdict was "hopefully just condensation."
Well I agreed just hoping that was true. I took off my intake to replace it with a better one and while I did that I accidently let coolant get in the oil.
Before I did anything else I drained the oil and poured some fresh oil over the lifter valley and drained that. I put the new intake on, started it up and see smoke coming from the front gasket of the intake. It ran for maybe 2 minutes before I noticed this.
So I take the intake off this time and remember to drain all the coolant so nothing gets in the oil. Well just out of couriousity I drained my oil and there was some coolant in there This time I didnt let any coolant get in the oil when i took off the intake so my suspicion remains.
I ended up reinstalling my new intake with silicone as the front and rear gasket and new intake gaskets with silicon. Then I reconnected all the coolant hoses and refilled the coolant. I put a pressure tester on the radiatior and pumped it up to 16psi which is what the cap says. It seems to lose about a lb per minute of pressure with no visual leaks of any sort. I am a little scared that one of the coolant passages in the block was cracked.
What do you guys think about my situtation?

 

Head gasket.

 

If it were the head gasket wouldnt coolant be leaking into the cylinders? Not into my oil? I was thinking and hoping that at first but it just didnt seem to work as an explanation. The other thing that swayed me away from a headgasket it that I dont have much run time on this at all and it never overheated. This is a fresh built engine.
Anyone else think it could be a headgasket?

 

it is possible. but i can't say for sure if that is your problem.

 

Intake gasket is my guess.
A cracked block is so rare that i'd doubt that's it.
Were the heads ported by chance?

I had to replace my intake gaskets 2-3 times this build before I stopped getting water in my oil. Not sure how I managed to screw it up that many times, but that was the only logical answer and it doesn't leak now so....

 

Yes my heads are ported. the ports are huge also, but i figured if the guy who ported them went through the water jackets that again they would leak into the cylinders and that isnt happening because i pulled all the plugs and they are dry.
I was thinking the intake gasket, but I am pretty sure I am doing it correctly and I am using the felpro 1206...
I am putting silicon around the ports and the water ports on both sides of the gasket... I cleaned the surfaces of both mounting areas. I dont know what else to do. I REALLY hope i dont need to tear down the block.

 

The valve spring seats could be cut too low.
Your pressure test leads me to believe it's not leaking. 1lb/min is error in measurement or error in how you set the thing up. I think that's ok.

What heads are they? 1206 are big gaskets, you sure they aren't overlapped?

 

The heads are Victor Jrs 2.08 1.6 valves. I bought them from someone whos friend got in a car accident and couldnt use them anymore... They were never used/ mounted before I got them. They were however ported to what looks to be a 1206 but could be a 1207, the difference between the 1206 and 1207 is very minor. So I decided to go with a 1206. I am using an Edelbrock super victor intake since that is the only intake that will cover the ports.
I dont believe that the person had the valve seats cut. The heads were brand new and looked to be professionally ported. The port job looked very good.
It is auctually leaking less then 1lb/min but I feel that it shouldnt have a leak at all...

 

What is the history of the block before it was turned into a 383.
Was the block taken to a machine shop first and gone over, or was that part skipped?

 

Yes, it is an 85 block out of a corvette. I bought it from a trustworthy person on here that had the machine work done for me. The block was bored .060 over, the shop also put new cam bearings in, installed the freeze plugs and it was also decked.

 

Ouch, I was kind of hoping to hear that it wasn’t decked. Would have definitely left more room for head gasket issues.
Right now I am leaning more towards the coolant passage like you mentioned.
Not sure how you would verify a bad coolant passage without a lot of expense.

 

Yup, it was decked and the heads were checked for flatness just so I would be safe.
I used a generic headgasket from a rebuild gasket kit... it seemed like a cheap gasket in comparison to some of the ones i see being sold. Could a cheap gasket maybe have caused this?
My plan once it stops raining is to keep putting pressure on the system with the drain plug off and the oil filter off and see if any coolant comes out. If some comes out then I most likly have a problem but if none does then hopefully I am fine. What is worrying me is that i am losing pressure and not seeing a leak...

 

Pull the pan and redo your pressure check. They might have gotten into the coolant passages when clearancing the pan rails for rod clearance.

Cracked blocks aren't that uncommon. I've had two that were cracked in the lifter valley above the lifters. Typically from freezing. One was in Colorado, the other in San Diego (it does freeze inland and at higher elevations in San Diego, but not everyone uses antifreeze there).