New 360 build with oil leaking into coolant

[chermik1999]

Hi guys.

Have another build on the go. This time a 360 LA 72 block.
Without all the details, some brief history is as follows. 10.5:1 KB, all new and machined parts. Block is one that I've had kicking around for some 10+ years. Originally it had 8:1 and mild cam. Was a short block for sure as it needed everything including a crank bolt..lol. Bought from S &S in Spokane.
Decided weeks ago to upgrade the pistons etc and get the build started.
Aside from a bad set of speedmaster valves on one head, got all that sorted with a new set of PW heads.
Was working today to get it all ready for breakin Monday when my pushrods arrive from Smith Bros. So got the wires set up and only thing left was to get it primed to make sure that was all good before buttoning up the intake and top end.
Started well with 70-80 psi oil pressure. Turned engine over as usually to get oil to the rockers. Did it 2x per side to make sure I didn't miss anything. Then this:

Ran out of oil like dry in the sump. I thought well maybe the filter ate it. So added 2 more qts over the original 5 qts having a deep rear sump pan. Then noticed oil pouring out the waterpump??? What the heck...

So took a break then started back to troubleshoot. Did I miss a plug or something? Nope..all there.....

Turns out the pass side coolant bank had all the oil. Popped the drain plug and drained the rest of my lost oil.

Now I'm stumped...did pressure tests in each hole. No problem there so no blown head gasket. Ran a scope in the holes looking for a Crack or something. All look OK.

Then I remembered something during the build. While I was working in the block, I noticed something like a loose bolt in the block. Turned out it was a piece of casting on both coolant banks. I had to remove both frost plugs to get them out. Both in the same location on ea side.

My builder machinist told me that's common on old blocks that were cleaned. It's old rust and crude build up and then just let go. You'll be fine. Finish the build.

Well now I'm not too sure....here are the pics of what I found....any thoughts or same experience?

 

[RemCharger]

Maybe try pressuring up the coolant system and see where it's joining the oil system??

 

[chermik1999]

Yuup...that was next plan. As the intake is off I'll make 4 plates to cover the coolant passages. Then plug the water pump outlet and large return. Just leaves the heater inlet to run some pressure.

 

[chermik1999]

I found these in the center of ea side. Removed frost plugs to remove as was too large with a grabber...think they came from somewhere?

 

[Demonic]

Head bolt too long and cracked a bolt hole?

 

[Bighouse]

Head bolt too long and cracked a bolt hole?

Or oil in a bolt hole somewhere and hydraulically cracked tightening.

 

[chermik1999]

New ARP bolts for the block. Block is fresh and clean. No oil was put in until last night when I went to prime. Ran up to 80 psi quickly but was a long time to get oil to the rockers. Finally it came in as I was getting worried. That is making me think that the right bank has a hole somewhere where coolant meets oil rails. Left bank is dry in the coolant rail.
Will mock up a seal system and pressure test it today. I suspect that those chunks of cast are the problem.
With a .060 over bore and a piece of cast in the coolant rail means rust got cleaned out when it was cleaned and it had enough rust to blow a hole between the 2.

 

[RemCharger]

Head bolt too long and cracked a bolt hole?

Or oil in a bolt hole somewhere and hydraulically cracked tightening.

Reminds me of a guy that used to impact headbolts in.

 

[chermik1999]

Reminds me of a guy that used to impact headbolts in.

Haha..ya. see later today

 

[dvw]

Friend had a Koleno block that leaked oil and coolant together. Made a fitting for the oil pressure gauge port. Coonected it to shop air. It blew coolant out of the radiator. Turned out it had the right side oil feed hole in the block from the cam into a coolant passage. Easy test
Doug

 

[chermik1999]

Hum...that makes sense. But these are new heads? Gaskets only go on one way as well?

 

[chermik1999]

Also I finally made oil pressure to the rockers, but like I said took a bit. Didn't notice the oil out the water pump until the oil pump ran dry......but that sounds like what it's doing. See what I find later today with pressure test.

 

[chermik1999]

OK update.

Pressured coolant system and had oil coming through the right bank head oiling hole for rockers. Isolated that closed and seems its leaking around the oil pump?
Have a video but it's too large. I'll post it to YouTube and post link.
Can the oil pump be linked to a water jacket?

 

[chermik1999]

Well after many hours looking I have come to the conclusion that I may have a cracked block. Started tearing it down and checking for cracks etc. Not much I can do at this point.

 

[chermik1999]

So now that I'm over the shock, I still want to find it. With heads and water pump off, how can I pressure the system to check for the intersect? Run the oil pump with some cheap oil and look for leaks somewhere?
Would be nice if I could pressure the oil system with say 30 psi of air and see what I can find. Pretty hard to do I'm thinking.

 

[Timothy]

So now that I'm over the shock, I still want to find it. With heads and water pump off, how can I pressure the system to check for the intersect? Run the oil pump with some cheap oil and look for leaks somewhere?
Would be nice if I could pressure the oil system with say 30 psi of air and see what I can find. Pretty hard to do I'm thinking.

I think I would try to pressurize the oil system though the oil pressure gauge sender. Making sure to block off any open oil ports.

 

[chermik1999]

Well that's tough with open lifter bores etc.
Cam and crank are still in. Guess load lifters back in and check other possible openings. Maybe so yuup

 

[chermik1999]

Well going to get a helper tomorrow to run the drill. As the heads are off, I can have access to the water rails. I'll run a camera down each hole and see what I can find. That's all I can do at this stage with the next step getting another block ready for the parts swap.

 

[dvw]

Why not air up the oil gauge passage and see if it pressurizes the coolant passages. It’s a 5 minute test.
Doug

 

[chermik1999]

Today I did this. Left lifters and cam in place. Positioned where oil galleys were closed.
Removed the pickup screen and replaced with a air valve and shut off. Put gauge on the sender and applied air to the oil pump. Then sprayed soapy water in the water jackets with heads off on pass side (right bank). Ran a boroscope for the next 3 hours looking for air leaks.