water in motor?
 

Ok here goes. went out in the boat one afternoon was running up the river. Motor got to about 4600 and pop through the carbs. I shut her down. Popped the hatch and foam was comming out of the breathers. Had alot of condinsation on the blower,intake and valve covers. Checked the oil and it was dis colored but not frothy. So we sat for a few. then fired the boat and watched the oil pressure and water temp. All was good. so off we go 3200-3500 all the way back long run 45 min or more. Oil pressure and water temp never changed. Checked the oil when we got back and it was more sis colored but not frothy. What could this be from? Motor only has about 15 hours on it.

Motor is a BBC 515ci 8/71 around 6psi boost.

It sounds like it could be a head gasket or a intake gasket on the intake manifold. The head gasket could be leaking between the water passageway and cylinder. A leakdown test could elimanate the head gasket.

Thats what I was thinking. I orderd new intake and head gaskets. But the pop through the carbs would the gaskets have anything to do with that or is that timming.

I'd say once you find out if its the gaskets then run it and see if it still pops.

Ok I will. Thanks

What about risers? Could be a simple fix here.

Risers? Im running water jacket lightning headers. Maybe a header is leaking?

The concern is are the risers pointing downward or strait back. If it is strait then water is running back threw the exhaust valves.

here is a pic

http://www.hotboat.com/image_center/...60_0001_2_.JPG

The headers look like there in good shape i cant tell how much drop the exhaust is do you have a flapper on the tips to keep water from coming in when you come off plane. It could be a cracked header but chances are not.

I would agree on the head or intake gasket failure.How much boost are you running?
Even though the oil is somewhat discolored still should change oil/filter.

Yes there are flappers.

There was no issue before the rebuild was done. I bought the boat and this was the second time I had it out. So Im leaning twardes a gasket or my oil cooler.

About 6 psi not sure. Im installing a boost/vac oil temp water pres. and a fuel pres. gauge. I am going to change the oil and filter then run the motor and change it agian. Then go run the boat and see if the gaskets worked.

I think your on the right course of action.i've got friends that run blower motors with high boost and they are always blowing head gaskets.you'll be fine.

I hydrolocked my 502 last week from a leaking exhaust riser.At the shop now but haven't heard yet what kind if any damage.

Damn that sucks.

Im hopping its mine not anything more than gaskets.

Hate to be the bearer, but i'd guess you will most likely need a new crank/rods if it truly hydrolocked. It can weaken the rod/crank to the point that it will run for awhile, then fail.

This is damage that can not usually be seen by the eye. Can't say it for 100% that it will happen to you, but I've heard this story before and Murphy's law prevails.

DaveO what is the chance that when the motor was put together no one checked to see if the head bolts ran thruogh any water passages on the heads and there for they didn't get sealed properly?

Compression check and leak down check should be the first order of business. If nothing is found (which more then likely there will be) you can pressure check the water system fairly easily. Water comes into the motor in one place and exits in 2. I used radiator pressure checker to test mine, worked well. If you test it right it will include everything from the sea pump to the inlet to the headers.

I would say 9 out of 10.

Thanks That could tell me more about my cooling.

I would say that would have nothing to do with a backfire through the carb

not the backfire but could be why there is water in the motor.The backfire Im guessing is a timming issue.

What's your water pressure @ 3000, 4000, and 5000 rpm? My Eliminator for whatever reason had extremely high water pressure above 4500 rpm. I could run all day long @ 4000, once I reached 4500 it would leak water pass the intake gaskets every time. Took me a while to figure it out but my water pressure was spiking to 40 lbs:eek: . I installed a relief valve and a dump out the rear and never had a problem again, 20lbs. of pressure wot.:D This might be something to check.

Ive heard that also but Im running my pick up through the drive. not an exturnal pick up.

Mine was through the drive also. Just a thought??? I had the milk shake in the v/c's and breathers. Pulled the intake and the valley looked like pudding.:eek:

I have heard that from more than one person. It might be a good security just to put one in.